Search for Bridge Oscillator help needed in Topics

Wein-Bridge Oscillator help needed

I've been searching google for about an hour now, and I need help with making a Wein-Bridge Oscillator. What I need help on:- Can I use any op-amp? I want to just go buy one at radioshack (don't feel like paying 7 bucks for a tiny IC online)- What kind of incandescent bulb should I use/is there a more modern substitute?solved by killerjackalope- Is there a way of controlling the frequency with only 1 potentiometer (I found this website but I still have the same questions as above and I don't know if it'll apply).-how much power does it consume assuming there's only a light load on the output?

Topic by guyfrom7up    |  last reply

Circuitry help needed!

So I'm working on a project to build a binary clock style watch. I have found a fairly simple system to replicate though I plan to downsize the circuit to fit within roughly a 40x40mm area, the height I am not too concerned about right now. Here is the link to the project I plan to replicate: with the circuit presented I plan to break it into two boards(possibly three). The top board would utilize 2.8x3.2mm LED chips and connect them properly for the ATtiny and shift register. The second board would house the resistors, ATtiny, shift register, and buttons. It would connect to the LED board via vertical wires that would pass through the LED board and hold it directly above. On the bottom of the second board would be the battery holder and wires to directly connect the positive and negative leads to the needed inputs from the backside of the board. This would result in the second and third boards being back to back. (And I do plan on designing and etching my own boards for this project)So my questions for you are:I want to add a 16.000 Mhz crystal oscillator to the circuit to increase the accuracy of the internal clock of the ATtiny, so where would I add it in?How could I reduce the output power from the battery to run the system on minimal power so that my battery can last a year or longer?And is there such thing as a dual sided pre-sensitized pcb board I could use to make the circuits?

Question by Tman179    |  last reply

Need urgent help in H-bridge!! Answered

Hi,      I am building a H-bridge to drive my robot's motors. I am using the circuit from the following link     (Figure 12). For the mosfets I have used IRF540 and IRF9540. The moment I connect this circuit to my 12v power supply, the IRF9540, heats up very quickly although I have not connected it to any load !  For logic input, I am using the Arduino. Please help me with this H-Bridge circuit. Thanks in advance.

Question by Jayvis Vineet Gonsalves    |  last reply

I need help setting up a 2Mhz oscillator circuit

So here's the backstory : Last night I was poking around in our shed looking for ..... when I came across a box of old electronics. Inside was a lot of old parts, from about the 1970's, a few 555's and 741's and a big 28 pin chip I didn't recognize. After plugging the numbers on the chip into google (AY-3-8500) I found out that it was freaking pong on a chip. Apparently my dad had bought it as a kit in the 70's but never got around to make it.So I took a look around the net for schematics and found's the problem, I don't have easy access to the 90uH inductor in the schematics or a 2Mhz crystal.So how can I create the 2Mhz I need to run the chip? It's the only thing between me and pong X(

Topic by greendude    |  last reply

Need expert engineering help to build a foot-bridge!?

I want to build a foot bridge across a creek! The width of the creek is 16', but I'm going 24' long to support the footers. The bridge itself will be 4' wide. I was thinking of using "C" channel iron welded onto I-beams to hold the treated 2x6's in place. I need info on what type and size of beams, etc. If it's not too obvious I'm a complete engineering noob, but this is the kind of project that makes country living worthwhile. Thanks in advance for your kind help!

Question by FyreAntz    |  last reply

Diodes for Bridge Rectifier?

 Please Help! I need to make a bridge rectifier for a shake charging flashlight which also include using a 5V regulator - so it won't be a very high voltage, if that matters.  What type of diodes do I need for this bridge rectifier?  HELP!  thank you! patti :)

Question by mckywer    |  last reply

Hartley or Colpitts oscillator

I need Hartley oscillator or Colpitts oscillator. I tried a lot but failed. I am simulating circuits on multisim but not been able to get sine wave. Can anybody help me with that?? I am using these oscillators because I want high power oscillator in high frequency range.

Topic by m_uamir72001    |  last reply

bridging my connections

I need help bridging my connections. everytime i try it says i must select two LAN connections that are not using internet connected sharing. i have looked all over and am pretty sure its all off, it wont let memerge the two together by highlighting them either it just moves the connection order around please please help. thank yoou!!!?

Question by RECONWARRIOR    |  last reply

Need help with guitar ground wiring! Answered

 Earlier this year I bought a super cheap Squier Affinity Telecaster. A couple weeks ago I opened it up to change a tone cap. Every thing seemed fine, all the pickups worked the tone control worked the switch worked and the volume control worked but I noticed that there was quite a bit more buzz and it would stop whenever I touched anything metal on the guitar. Ground problem right? Anyway, I thought I had accidentally snapped the bridge ground wire or the main ground wire (the only ground wires that weren't 7 strand). So I ordered some 7 strand luxe cloth wire and replaced both of the ground wires. I tried the guitar again, the buzz was quieter but was still there and it reacted the same way as it had before when I touched it. The buzz stops when I touch the bridge, anything in contact with the bridge (i.e. strings), and the control plate. The buzz is very faint and the reaction to me touching the guitar is even more faint.   My soldering skills are pretty poor. I think it's likely that my solder joints are the problem but I would also like to know if there are any other possible causes because since the first time I have redone the solder joints a number of times.  If my soldering is the problem what is the best solution to the problem other than connecting myself to the guitar via wire every time I play? And what is the best way to improve my soldering skills for future projects or even this project? Thanks, Adam

Question by adamgillies    |  last reply

PSP Fix, Need Help

Hello all! I recently aquired a broken PSP 1000 as sort of a challenge to myself. Now however, I actually want it to work. I need some help with the fix, so here are the problems I have been able to identify: -PSP won't always charge, I strongly believe it is the battery though. When I tilt the PSP around at different angles, it will charge. Also, fiddling with the battery makes it charge. -PSP won't tun on. I have checked the power fuse, and it was burned out. I placed a jumper across it like so many internet guides say, and it now has continuity. When I hold the power switch, the PSP will do one of two things:                                  1. The light will turn off, and then turn back to solid orange (charging)                                  2. The light will turn green for about 0.5 to 1 second, and then turn off -PSP will make a rythmic clicking when not charging, doesn't seem to be a problem though. -Battery is cracked, and I don't know if it works properly because it won't maintain proper contact with the PSP. I have also checked the backlight and USB fuses, they both have continuity  so I'm not worried about fixing them. Right now I would just like it to turn on. If anyone knows anything, please make a comment, perhaps someone else has this problem. P.S.  What is a pandora battery? I keep hearing about those, what do they do? Also, what exactly signifies a "bricked" PSP? Thanks UPDATE: 11/08/2009 I had a friend test the battery, he said the battery works and he charged it for me.  Now the PSP turns on. But, (there's always a but) there is no activity on the LCD. I tried bridging the backlight fuse with tweezers to see if the fuse was the problem, no luck. So what now? All I have learned is that the charge circuit doesn't work and that the PSP turns on with no activity. I held a white LED flashlight up to the screen, but I didn't see anything. any suggestions?

Topic by gimmelotsarobots    |  last reply

Using the IRS2110 for 36v H-bridge? Answered

So i have some 850W 36v DC motors that i need to design an H-bridge for, and ive decided to use the IRS2110 to driveing them, since i need to drive the highside fets. I however have no idea of how to use that chip. Any help? :P

Question by dumle29    |  last reply

Reefing it with LED's (help needed)

Well this is my second post and I am a bit more learned in the ways of LED circuits from many of your posts. Objective: Create a high light output LED array that will peak at around 16,000K for growing coral for reef aquariums.Primary strategy: connect 10 or more Luxeon III stars in seriesPreferred requirements: Energy efficient, Low Heat emittance, Needs to peak out at the appropriate spectrum for the coral ( I have that covered just by changing the ratio of cool whites to royal blue Luxeon III's)At the moment I a just going for a simple on/off, later i would like to employ a form of automated dimming so that it fades on and off so there is not such a sharp on off with the LED's. So far I have a circuit that i plan on modeling my LED array after since it was readily available for me to dissect. The following is an LED array. I know that there is a diode rectifier bridge built in there and a smoothing capasitor but there are to components i do not recognize they are connected at the positive and negative ends of the circuit. One is the Yellow (doohickey with part # 684j 250) component attached to the positive lead and the other is a clear (fuse/resistor hybrid) component next to the resistor on the board. was able to draw the circuit and it seems pretty straight forward but I just need to know if I will be able to spec the appropriate components to operate 10 leds in series (Each LED operates with a Vf=3.9 V and I= 1000mA ) they will need a supply of more then 40V DC.Any help or dialogue I can get the more the better and the more I will learn In addition I looked at Dan's high power constant current but not sure how well it would operate under the conditions that I have specifiedPrimary LED's in use for the Reef light: (note all are stars)LED part # Color Type Vf Amps Lux LXHL-LW3C cool white Lambertian 3.9 1000mA 80lumensLXHL-LR3C Royal blue Lambertian 3.9 1000mA 445mWLumensLXHL-MW1D cool white " " 3.42 350 mA 45 LumensLXHL-MRRD Royal Blue "" "" 3.42 350 mA 220 mWLumensThere was little to no difference between the 700 mA series and the 1000mA series so I did not list themI look forward to all your helpTom

Topic by Aquatope    |  last reply

Do the bridge pin holes need to be tapered?

I am replacing a bridge, on an acoustic, the new bridge does not the peg holes drilled out yet. I found one site that says to ream with a tapered reamer from some company. This has got me worried because I have drilled the holes to 3/16" but the pegs don't go all the way down. I have not gone to my go to guy yet cuz its almost twelve thirty at night, please help.

Question by addicted2paintball    |  last reply

Help! Building an optical pickup for a bass guitar.

I am building a bass guitar and would love to have an optical pickup on it. I am a experienced with building circuits but i need help. This is what i know so far. There will be an ir led on one side of the string and a photo diode on the other. This will cast a shadow on the photo diode to make an analog signal. One led and one sensor for each individual string. Then I am lost, all I know is that it has to go though an oscillator of some sort to produce the sound. If anyone could give me a good schematic that would  be great.

Question by kyrisroy    |  last reply

Need help with MOSFET h-bridge; gets hot when using PWM frequency of ~500Hz. Answered

Hello, I recently bought an Arduino and used it to control a MOSFET h-bridge circuit.Everything worked fine until I started using PWM to drive the motors.The PWM frequency is about 500 Hz and I've already tried switching out the 1N4004 flyback diodes in the h-bridge circuit for 1N5819 shottky diodes but it didn't help. The schematic of the h-bridge can be found here ( ) What should I do? Andy

Question by Monoclecat    |  last reply

I need help with modding my original xbox, can you help?

I found an original xbox (1.0 motherboard) at a garage sale because i wanted to put linux on it. I softmodded it with the splinter cell exploit like on this. I now have the xbox at the modded xbox dashboard. I wanted to put in a new hard drive so it would have more space for linux and installing stuff. when I plugged in the hard drive it didn't boot up. I think I have to replace the BIOS with cromwell (using raincoat). I know you have to make 2 bridges on the motherboard to rewrite the BIOS and i have done that. Now I'm at a confusing part, do i have to use bSOd to flash the BIOS or is there something else i have to do? Thank you for the help.

Question by orangecrush    |  last reply

BRIDGE RECTIFIER ? used electronic transformers 240AC in, 65va max - 12AC out,, to power LED strip lights?

Hi, I need help to understand what I would need to use a bunch of these (free) old transformers to power various 12vdc LED strip lights in my garage.          I have read-up on the subject of using a bridge rectifier in each circuit to convert the AC to DC,,, BUT,, being completely useless at formula / algebra / maths, I cannot work out which bridge rectifier would work for me. I can adjust the length of LED strip to suit, but the longer - the better!  The LED strips I have are 5m long, 300leds, & the specs say 5amp for the full length. So, is there a bridge rectifier available to buy, what number is it? (same if I need anything else)  Please help,, and try not to baffle me with techy science.  Many thanks.

Question by bowtie262    |  last reply

Circuitry help needed - microcontroller in binary clock

Ok, so I am currently working on a project which involves some circuitry and programming. I am planning to make a simple binary watch. Now with my current plan I am planning on making 2-3 circuit boards depending on what I can get. The first circuit board will connect the leds for the time read. It will be a standard four column hour and minute binary clock readout. The second board will contain an ATtiny85 microcontroller, a 74HC595 8-bit shift register, two push buttons, two 10k ohm resistors, and four 220 ohm resistor. The third board will be glued to the bottom of the second board for the battery holder and some extra space to add wire tracing. Now I plan to design and etch my own pcb boards and solder them together. Though for the second and third board being glued together would add a bit of thickness so I am wondering if I can buy a dual sided pre-sensitized circuit board to etch?Thes plans are based off the work of another user on here, link to his clock below: Credit to him for this great and simple system. With my very limited knowledge and understanding of circuitry and programming, this is one of the most straightforward clocks I have found. This is general format I will try to follow, though I do wish to make some modifications to the circuit or program based on what is possible with the circuit setup. First I am concerned about the power consumption of the system and how I can reduce the supplied power to make it run on a watch battery and run for about a year if possible or longer. Second I know that adding a crystal oscillator can improve the accuracy of the clock by synchronizing the internal clock on a set frequency. So with that, how would I add a 16 Mhz crystal oscillator to the circuit? The program that is given in the project runs based on the internal 16 Mhz internal clock of the ATtiny85. Third question is what system works best to program the ATtiny85? I have a Raspberry Pi 3B+ and I also have Syper IDE and I am fairly good at programming with python. So could I program the ATtiny85 with my Raspberry pi and use python? Or would I have to use a different board and language to program the micocontroller?

Topic by Tman179    |  last reply

stepper motor question

Ok, i am trying to make a chain clock, its just a clock with a gear instead of a minute hand that turns a chain with 12 numbers on it. my problem  is; the chain i am using is too heavy for a conventional quarts movement. i would like to use a stepper motor but all the drive circuits i find need an arduino. are there any simple circuits i can make, to use a stepper motor for a clock? i do have some circuitry skills so i can work around some stuff. thanks for the help :)

Topic by golddigger1559    |  last reply

Need help powering two circuits on a single power supply

Hello, I need some help with a project I'm working on and hopefully someone has an answer. I'm building a white noise generator  and it consists of two circuits, the white noise generator and a amplifier. Now when I bread boarded these I had each circuit built on its own bread board powered by its own 9v battery supply, but I want to have both circuits powered by a single 9v power supply with a 5v voltage regulator. Now when I bread boarded the device it worked fine using two 9v batteries powering the individual circuits, but when I connect them to a single power supply the circuit starts oscillating instead of generating white noise.  I've tried all sorts of different ways of rewiring the circuit, but I can't get it to run on a single 9v source without it oscillating. I think it has something to do with the amplifier signal feeding back into the white noise circuit. What I can't figure out is why it works when powered by two separate power sources and not a single power source. Anyone have an idea of what's going on here? I could really use some advice.

Topic by nfortier    |  last reply


Dear Experts,This is my circuit diagram,I am Using1. SELF-OSCILLATING HALF-BRIDGE DRIVER ( IR2153 )2. MOSFET ( 47N60C3)I have a problem is the circuit sir,it works better with 10 Ohm resistive load but when I connect an inductive coil (which has very less resistance and homemade using coils) and a free-wheeling diode across it, I am facing a problemProblem: Power supply is in constant current mode at most of the time and 5A and 8V drop which is the max that I can achieve my power supply is 30V, 5 Amp power supplyRequirement: 12V-15V drop at 1-3Ampswhat could be the necessary arrangements to achievewhat are the possible ways to achieve this?

Topic by m.a.dasunumayanga    |  last reply

help with a chaser board

Hi all i am very very new to all of this and i am working to light up a model if you can help me i would be very great full. Ok so i want to connect Led 1 threw 5 to the 555 timer and 6and 7 to be solid on. The resistors are 1/4 W 5% 470R OHM I was told to put the resistors on the negative point of the LED for the chasers. Do i need to put some on the Solid ones? I am using 4 AA Batteries for power and that gives me 6V. All of the lights will be in a serial circuit. The chasers Led are 3mm 5.0V @ 20mA The solid Led are 3mm 3.6V @ 20MA The fun part: How do i connect it all together? I bought a Breadboard and i am trying to figure it out lol !!! Now i was told that the timer chip is to bridge the gap image 2 That i also has to connect the the bottom and top of the gap like so image 3 OK so on the breadboard the resistors go parallel? from the 555 chip image 4? And the Led goes like this for the chaser image 5 ? Any help would be great and thanks

Topic by doormanwade    |  last reply

I need help setting up my H bridge for a motor design

Please help me ! I am working on an electric motor design, and I am having trouble understanding the sizing of the resistors required to set up my H bridge. If you look at my diagram you will see each phase consists of four power coils wired in parallel . There are two sets of reed proximity sensors that turn the circuit on one way then the other. I am using a TIP 35c & a TIP 36c for my Transistors I am using a 1n4936 for my Diodes I am using a PRX 8200 for my Reed Sensors  You will find data sheets attached  So far I have only been running my project at 12 volts DC . At 12v the transistors are running cold with no resistors at all. I have tried to apply OHM’s Law but I’m not getting it right. I am confused about a few other things as well. The Data sheet for the Transistors tells me the Base- Emitter Voltage is 5v & the Base current is 5a . Should I be running a separate power supply for the sensor feed to the base ? Or dose the resistor adjust the voltage for this? When you buy Resistors they come in 1/4 watt ½ watt 1 watt 2 watt etc. How do you choose the wattage? I would like to run my motor in 24, 36, 48, or higher voltage, to as much as the transistors will take , but until I understand this set up I fear I will only fry my transistors or sensors if I get it wrong.     Can you help me turn up the power?

Question by Masternot    |  last reply

Calculate capacitance across full wave bridge rectifier? Answered

OK,so I need an AC to DC converter.I used a 9 Volts transformer to convert 220VAC to 9VAC,then rectified it to 9VDC using a full wave bridge rectifier(IN4007).I need to know the value of capacitance which is to be connected to the 9 volt DC output(I heard somewhere that its got by multiplying the forward current*5 then dividing it by input voltage to the rectifier and the result is obtained in Farads........well I'm not sure if this is right and I need clarification).I've currently used a 1000uf capacitor and my multimeter shows the dc output from the bridge as 14 volts which is really confusing because before I used the capacitor it showed 9 volts.I really need a way to deal with capacitance.Pls do help me. I've added some pics(not much of help but.....)

Question by Adarsh_tronix    |  last reply

dc- motor ultracapacitive skateboard

Need help in this project as I am abit lost with the programming of my project. My skateboard will be able to charge by manual moving and then discharge to electrically move the skateboard when needed. Im using an arduino board and I need to program a H-bridge with pwm and controlling the motor speed. Hope somebody can help me out asap. Thanks!!

Topic by Nicktyw  

Need some help with a parts list for a RGB array.?

Im saving up money to build a wall of 512 RGB LED's from a site called solderlab, and they provide real good documentation, and pics, but im still confused on what I need EXACTLY for the PCB boards. There will be 8 with shift registers, and one for power. I will link pictures to the schematics, renders of the boards. And Ive got some, I think. Also where I can get the custom PCB's made, and or, how much they will be! :D  Heres the Power board: Render of the Power board: One of the 8 Shift register boards: And lastly, The render of The shift register boards: And as far as I can tell, I need: 36 RJ45 Jacks 32 Shift register 74HC595's base resistors 10k Conrad Electronics 64 npn-transitors BD139 Conrad Electronics 64 34 pin ribbon cable connector 3- 22p ceramic caps And they say ( but im not sure what or where to get them) Pull-Up / Pull-Down resistors 10k     x5 4 x pin header quarz 16MHz (Im assuming this is just a 16 mhz crystal. And two Electr. Caps 100 µF So what am I missing? and how do I make/get those little wire bridges? Thanks! :D Im excited.

Question by 'earl    |  last reply

help on mutiple steppers on arduino mega

Hello, I am hoping to get some help for my project here. I have three steppers that would like to control using an arduino mega first question is: is this possible? in other words can i connect the wires from stepper (bi-polar and 4-wire) directly to the arduino pins? secondly, is there a sample code that i can use to make the steppers sweep independently? are there specific libraries i need to use? Regards, Behzad.

Topic by karim_bj    |  last reply

how can i fix my bass guitars electronics wiring? I have a disconnected jack and ground wires that need sorting Answered

I have a bass with some wires lose in its wiring. the output jack has come off- there is a red wire and a white wire going to it, i know where the red wire goes because that came off whilst i was fiddling, i presume the white wire goes to the only other contact? Also as well as the red and white there was two bare ground wires that had snapped off inside the heatshrink, where should they be connected to? Also the ground wire that goes under the bridge is lose, i need to know where that goes. The thing is that the only place i can see broken wires from the solder blobs on the jack is where the white wire should go but that would mean the white wire + 3 ground wires all soldered to the same contact, does that sound right? Hopefully the pictures will help you imagine the situation a little better, as i haven't described it very well. Thanks to anyone who helps

Question by mdog93    |  last reply

Control Logic with PWM? Answered

I am currently working on a robotics project, and need a bit of help. I have this H bridge, and would need to control it via PWM. Speed control isn't necessarily what i need, though i wouldn't mind. (In4 i should have just bought an ESC) The whole bot is controlled by PWM (All servos) except for the two DC motors that i have on it -- One for forward and backward, and another for rotating an arm. How would i control the H Bridge with PWM? Which pins would i connect what to? 

Question by RocketPenguin    |  last reply

Wiring up a filter copasitor?

For my Cold Fusion Project I was told to use a filter copacitor with the isolating transformer and the bridge rectifier.  I have had some trouble understanding this.  The mains AC runs through the isolating transformer and right after that I need to hook up the filter copacitior.  How do I know which is positive and negative.  I know AC alternates between + and - but when I need to hook it up to the rectifier I need to find + and -.  How do I do that?

Question by Kalrag    |  last reply

Crystal radio help anyone?

(If you want the blow-by-blow of my questions, skip the following gigantic piece of text and proceed to the 2nd list after the first)   I was reconsidering making a crystal radio the past week and so I set out to research the topic on the 2nd most popular information database on the internet which comes out of the 1st most popular one. According to wikipedia, all you need is one diode in order to split the AC signal coming in via the antenna in half, therefore it uses half-wave rectification (it's not quoted; it's what I understand from it). Could full-wave rectification be also used? Like connecting the antenna to a bridge rectifier (aka. diode bridge, aka. 4 diodes stuck together)? I know that half-wave rectification yields pulsed DC, but I also don't understand how. By that I mean what happens to the other half? Does the other half of the wave connect directly to the output? One last thing, I know the largest metallic object I can ever use as an antenna is basically just my roof, but then I don't like coming up to the roof and looking for some exposed metal to connect to. Any thoughts on what huge, metallic items I can use in my household? I've already thought up a list of what I could use for an antenna: -Window screens -Extremely long piece of wire (I have an 8 meter long CAT5 cable going from the 1st to the 2nd floor) -My front gate -Sheet metal laying outside my front door (not the gate) Here is the summary of all my questions: -Is this wikipedia article true? (see at the list "semiconductor" area) -Can full-wave rectification be used on such radios? -In the case of half-wave rectification, where does the other half of the signal go? -What can I use as an antenna (excluding my roof)? Aside from the asked questions: -Is there any other way to tune to a particular frequency? -I'm asking opinions to people who know what they're doing (no offense to beehard44, this is more of a poll that anything else).

Question by nutsandbolts_64    |  last reply

How to set 2-wire into bridge mode? Answered

Hi everyone! I have a 2-wire 3800HGV-B wireless router from AT&T; that I need to set into bridging mode not DMZ.  I have a DD-WRT router that I just installed on my home network, and I also have a small server.  Before the DD-WRT router, I had the server on DMZ on the 2-wire, and after I setup the DD-WRT router, it made me put that into DMZ mode.  I tried connecting the server to the DD-WRT and putting that on the DD-WRT DMZ mode, but that doesn't work.  I've tried using port forwarding on both my 2-wire and DD-WRT routers to send specific ports to the server on a private IP address, but that isn't working either.  The best solution I can come up with is to put the 2-wire into bridging, and a friend of mine did it with another 2-wire router (not the same model... he tried to help me out and wasn't able to do it), so I think it's possible, but I've tried to do it with no luck. I have tried Google, but everything that comes up that claims to be bridging is just setting the router to DMZ. Any help or other suggestions would be appreciated!  Thanks!

Question by thegeekkid    |  last reply

I have 2 rough-running, four-point, orbital, oscillating buffers that need to run smooth again.

These are heavy duty, 2-handled, 2 Amp, 3240 rpm, four-point, orbital, oscillators that were converted to professional massagers. Both of them now run really rough and I can't keep buying new ones nor can I afford to ship them back to the company for refurbishing. I assume they only need lubrication, but I can't figure out how to open them up nor does there appear to be any one around here who repairs power tools. (Rock and a hard place, eh?) Can anyone help? I have a photo, although those two black knobs do not exist on my units.

Question by NYCtherapist    |  last reply

A little help with identifying Ceramic Capacitors?

A friend asked me to fix his tv's power supply, and i accepted the challenge. Upon closer inspection of the circuit board of the power supply, i saw that a resistor bridge, a rectifier, a diode, a capacitor and 2 power transistors were blown. I purchased the appropriate replacements, and as i was about to install them earlier today I saw that two ceramic capacitors are blown. One of them has '684J' printed on it, the other has "SCK 206 or 296" printed on it I need a little bit of advice on what replacement capacitors to buy, or if i should take them out of the circuit. I could leave them out, because they seem to hook up to a rectifier and then to a transistor, but i would rather buy the appropriate replacement capacitors. Thanks!

Topic by Sandisk1duo    |  last reply

Driving DC brushed motors with Pi/PWM/Arduino? Answered

I have a few motors (2) that i would need to be able to drive via a PWM input (Probably from pi/arduino). I have been looking at H bridges, and that seems to be my answer, however, I can't figure out which one i need... The motors are identical 9v ~2 amp stall current motors. I would need both directions for each, and would obviously be using an external power supply.  With that said, which H bridge would suite my needs, along with what type of setup? I only have abut 4-6 PWM pins left to use, if that helps.

Question by RocketPenguin    |  last reply

Why my quadcopter is oscillating and crashing after taking off?

Hi guys, I am new to this multirotor domain. We are strugling with our first F450 quad. Below are the specs: 1. F450 quadcopter chassis 2. KK2.1 Flight controller. 3. FLYSKY CT6B --- 6 channel radio transmitter 4. 1400 KV Brushless motor 5. 30 amps ESC 6. Lipo battery Firstly the quad was not taking off properly. More over, after activating self level mode also, the quad is not at all stable. If we max up the throttle, then it flips in one side and crashes. Otherwise, it takes off from the ground upto 1-2 feet if we slowly increase the throttle and then oscillates and to avoid crash, we then decrease the throttle. Please see the video HERE for more reference. Please guys, really need your help in this matter. We are not able to understand exactly what is wrong with our quad. We have already calibrated our ESC's and the Accelarometer but no luck. Please help guys.

Question by RohitR66    |  last reply

Will someone please help me build the needed electronics for my hydrogen project?

Ok earlier I asked how I can build the needed 110 DC out of 110 AC.... I can't seem to get things going so I was wondering if someone was willing to help me?   I will be glad to pay a reward or payment or tip?? for anyone willing to build this for me...   I need it to plug into the house 110 AC then go through a dimmer switch then a diode bridge then a ?? resonator or filter? or ? then this would be placed into the hydrogen generator.. Of course I would not hold any animosity over any problems that may happen, I will simply have someone else do it... as I'm disabled and have problems with soldering.. so if you can please email me and let me know what you can do for me...  or if that is to much to ask, can you please send me all the parts I need and very detailed instructions... hahaha  OK?   or.... ??? I will be glad to send money for your time and the parts.. please contact me at        

Question by bboyden    |  last reply

how to convert ac to pure dc? Answered

I want to convert 5volt ac to 5 or less voltage! i got  a transformer it gives out 5volts dc! i used four diodes bridge ! but the current is still vibrating i came to know this by using a simple white led it vibrates! although the diode bridge converts it to dc but not in pure dc format help me!! can anyone give me a simple circuit to convert it to dc ( i have used diode bridge but it it is still vibrating i need some more out here to make it!!  )

Question by ubdussamad    |  last reply

Shake charger for a blackberry whose battery is 3.7 V. Would p a 5V regulator in still be too much voltage?

 Hi - I just need to know exactly what components I need besides a coil, a bridge recitifier and a capacitor I need in order to create a shake (faraday) charger for my cell phone.  Any help would be appreciated.  Thanks so much!!

Question by mckywer    |  last reply

How to create 120 VAC to 90 VDC Power Supply?

I need to create a 90 Volt DC Power Supply using a capacity, toroid and bridge rectifier. I know that with a toroid you have a primary (input) voltage and then you'll conserve power but have a different secondary (output) voltage. I know that if you put say 120 VAC in the primary, the outputs might be, for example, 50 Volts out, which are also AC. I want the voltage to be DC, so I know that I need a bridge rectifier that will boost the voltage by 1.41 because of the AC to DC conversion. However, you also need a big fat capacitor, and I have no idea how to size and select this. Help?

Question by Matt Adams    |  last reply

Can you help me with some circuit specs?

I am planning to build a driver control system for a variable speed DC motor. My initial design has shaped up as follows: AC voltage from a wall plug to a full-wave rectifier with a four diode bridge and a T or Pi output smoother. The rectifier would then be connected in series to the motor and a potentiometer, like a dimmer switch. Now the part that has slowed me down, the voltage range for driving the motor is 0V to 120V DC, which leads to the question. If I took out the transformer that is normal seen in a rectifier circuit to keep the higher voltage, what sort of specs would I need for the diodes, capacitors, and inductors in my circuit? Or is there a better way to obtain the desired Voltage range from an AC wall plug with out buying something costly?

Question by knotmuch    |  last reply

Help with adding LED's and mini fan to existing circuit.

Hello, and thank you in advanced for taking the time to read through this and give me feed back. I greatly appreciate it. So I have a working circuit that is running off a 3 prong 120 V AC 10 amp power supply. I thought i would pretty it up by adding a led lit power switch and another plane led in a different spot, and make it a bit more reliable by adding a fan on the inside of the enclosure. I downloaded and app that calculated how much Resistance I need from the power supply to each led and fan (all in parallel). After i hooked everything up to what i thought would be an easy mod. to my surprise I smoked the resistors in under 60 seconds.   I talked to a friend who gave me some basic direction but couldn't give me technical stats. He said i needed to start with a transformer (i believe is the term he used) to drop the voltage, then to go to a bridge rectifier to turn the AC current into DC, then after that i would need a current regulating switch to give the proper supply for the LED's and Fan. Then from there he said i would be able to calculate the Resistance needed for each Led and fan and would be able to hook up the resistors needed with out damaging them. If this is the correct steps to take I can understand that; however, he was not able to give me any technical info on any of these components and what i would require. If these steps are correct, what i need help with is to determine what specs i would need for each piece, Including the resistors after the current regulating switch. (Technical Info) The 1st LED im using is a Switch that lights up when on and has leads just for the LED (the switch is already being used and works). I could only find the style i wanted from an automotive shop so it says for the led 12V only(unfortunately i couldn't find specs on the amperage the LED takes, but the switch itself is rated at 5amps). The second Led is a basic Green Led that i Purchased from radio shack, It is 2.1 V and runs on 30 MA, The fan im using is from an old game console and is 5V and runs on 80MA. Thank you for any and all help you give, this went from what i thought was an easy stylish mod to me ripping my hair out and scouring the internet for info, i finally gave up and decided to join this great community to ask for help with my specif conditions. Thanks Instructable Fam.!

Topic by 3CEnterprises    |  last reply

Can anyone help me set up Guitar Rig and Reaper?? Answered

Can anyone help me set up Guitar Rig and Reaper?? I am able to choose the VST from reaper, it brings the GR4 (Bridged) Player and I can choose amps and such but when I add those effects to a MIDI track I get no output. I use Kontakt 4 with Steven Slate Drums on a drum MIDI track and it works like a charm I had to initially set inputs and outputs and save that configuration but it was a one time thing. do I need to do a similar thing for GR4?? any help will be greately appreciated.?

Question by doggyd69b    |  last reply

Stepper motor driver?

Hi! I am trying to find a good h-bridge for a 3 volt stepper motor. Basically my plan is to build a stepper motor controller with an arduino for controlling various functions in a model kit. I have the arduino-kit and the motors. But I need a good reference for a h-bridge, but all i can find are chips rated for much larger drive currents. Also exactly how hot does a hbridge get when under load? I would like to integrate the bridges into the kit, but since it is plastic, I would like to know in advance how hot it gets, and if it gets too hot I'll have to look at another solution.Any help appreciated! PS. If you can please put the hbridge part ID in your answer for easy reference. DS.

Question by feldreich    |  last reply

How to properly bridge 2 mono jacks using a 1uf capacitor and connect to rheostat?

Hello everyone, I am struggling on the proper way connect a few parts in my power source. At the moment I am about to wire my rheostat to a mono jack. From there I need to wire a 1uf capacitor to a 2nd mono jack. I do not understand where to connect each wire. I know how to wire the rheostat to the first jack but from there I do not know how to properly bridge the 2 jacks with the capacitor. I know I need to connect both jacks but how do I wire this? Do I connect the capacitor between both "ground" leads on the jacks? Does this also constitute  connecting both jacks in general? Also, the 2nd jack will be connected to the rest of the negative circuit in the source. I really hope I explained this well enough. I am new to electronics and I am still not that familiar with terminology so please bare with me. I would appreciate any help offered. Thank you in advance!

Question by alp0204    |  last reply

Reefer meets High Power LEDs (looking for help)

Well this is my second post and I am a bit more learned in the ways of LED circuits from many of your posts.Objective: Create a high light output LED array that will peak at around 16,000K for growing coral for reef aquariums.Primary strategy: connect 10 or more Luxeon III stars in seriesPreferred requirements: Energy efficient, Low Heat emittance, Needs to peak out at the appropriate spectrum for the coral ( I have that covered just by changing the ratio of cool whites to royal blue Luxeon III's)At the moment I a just going for a simple on/off, later i would like to employ a form of automated dimming so that it fades on and off so there is not such a sharp on off with the LED's. So far I have a circuit that i plan on modeling my LED array after since it was readily available for me to dissect. The following is an LED array. I know that there is a diode rectifier bridge built in there and a smoothing capasitor but there are to components i do not recognize they are connected at the positive and negative ends of the circuit. One is the Yellow (doohickey with part # 684j 250) component attached to the positive lead and the other is a clear (fuse/resistor hybrid) component next to the resistor on the board. was able to draw the circuit and it seems pretty straight forward but I just need to know if I will be able to spec the appropriate components to operate 10 leds in series (Each LED operates with a Vf=3.9 V and I= 1000mA ) they will need a supply of more then 40V DC.Any help or dialogue I can get the more the better and the more I will learnIn addition I looked at Dan's high power constant current but not sure how well it would operate under the conditions that I have specifiedPrimary LED's in use for the Reef light: (note all are stars)LED part # Color Type Vf Amps LuxLXHL-LW3C cool white Lambertian 3.9 1000mA 80lumensLXHL-LR3C Royal blue Lambertian 3.9 1000mA 445mWLumensLXHL-MW1D cool white " " 3.42 350 mA 45 LumensLXHL-MRRD Royal Blue "" "" 3.42 350 mA 220 mWLumensThere was little to no difference between the 700 mA series and the 1000mA series so I did not list themI look forward to all your helpTom

Topic by Aquatope  

Can someone help me with my Veeder-Root electro-mechanical counter reset solenoid ?

I have an old Veeder-Root electro-mechanical counter.   The counter works on 12V but the solenoid for reset seems to need a totally different voltage.  I have gone up to 24v DC which is as high any of my power supply equipment can go with no luck.   In desperation I tried to throw 120VAC to it and it buzzes so I am thinking it needs 120VDC but I am not 100% sure the best and easiest way to get it there.  I am guessing some sort of bridge rectifier, any thoughts or ideas?  I am working on a sculpture that counting is part of the look but I would love to have a pushbutton control to reset the counter. There is no model number but the Form NO is 1 159196  ELC    12V DC

Question by CharlesR88    |  last reply

I am doing a "plans" project in pre-ap high school physics and i need ideas!

This project is where I have to have someone else's plans for a project and I have to give a lesson over how physics works in the thing I make. I could make a building or bridge or radio and anything basically as long as its not outrageously simple and has physics behind it. however I would need to spend under $15 otherwise I have to submit what I am buying and how much each things costs ahead of time. if you have any great ideas and maybe could help with the physics behind it that would be grand! thank you!

Question by hefner93    |  last reply

My network is really screwed up

I seem to be fighting a loosing battle with my network, things just never work like they're supposed to.For example, sometimes I have to reinstall my network printer on both my laptop and my ibook to get it to print again, even when the server has been running fine sans problems for a week, it will randomly do this shit.Another example is, right now I "was" just trying to copy some music over to an external firewire drive on my server that I have shared. I had the permissions on everyone set to full access yesturday but I noticed when I restarted my server, it did not detect my drive properly until I re-seated the firewire cable :S Thusly somehow it lost my share configuration for my music folder.I set it up, but this time I left it on read only because I wasn't planning on adding any music earlier, itunes and everything was working fine when i mounted the volume. I went on there and changed the permissions back to full access just 20 minutes ago as I wanted to add some music to my drive, I right clicked in my mac os x explorer and made a new folder just to see if I could copy over now, it worked, aswell as deleting the folder.So I drag the 60mb folder of mp3 files over, and it just sat there...and sat...and sat.... until eventually giving me an error -36, upon searching about, it means "-36 ioErr I/O error (bummers)".That's straight from the horse's mouth, and that really tells me nothing, what exactly does "bummers" mean???It's frustrating for me non stop, and it does this to me with other shares in mac os x, or they will randomly disconnect for no reason, sometimes after 15 minutes or sometimes after 3 days. I will note too, I can't connect to my server now, it just says missing alias in the mac os finder. Yet I can VNC into it no problem, wowa, but just upon checking my pc just now, it can't access any shares on it either, the cursour is just spinning, however I usually have no problems with my pc's accessing it, other than the printer thing.I'm just so god damned frustrated with my set up, I've looked it up and down until I was exhausted, several times, and I know I must be missing somewhere along the way, but I just can't understand how it doesn't work like I want it to. Shares are set up, firewire is out of the question, permissions set up, mac os x can log into server, check. It's all good until I actually go to use it for something when I really need it.I'll have to restart my server now to get it to work properly was fine until I vnc'd into it to change the permissions, im gonna try restarting it now and just access it from it's own screen, perhaps vnc has something to do with it.Oh and to clear up any questions before they're asked, this is how I have it configured, as quickly and detailed as I can explain it:My network starts at my ADSL +2 4 port router/modem thingy (Speedtouch 546, it has it's own connection issues on the isp's side, but they don't seem impact LAN side data flow)That then gets split off to:*Port 1: iBook G4*Port 2: 25 ft. cable to 8 port switch (I'll explain that a little further down)*Port 3: 50 ft. cable to apple airport basestation in livingroom for wifi*Port 4: My main AMD PcMy ibook is configured for DHCP with manual address switch just makes the modem think I have like 5 computers hooked into one port lol...My airport, for a long time I thought was perfectly fine as far as usuage with my thinkpad, however, I've been noticing the last few times it's powered on, the airport connects to the thinkpad, but assigns it a address which does not exist on my network, but if I turn the wifi off and back on, it connects fine and assigns it a dynamic ip on my network.Other than that, I have it in bridge mode so that it acts pretty much the same as if the laptop were wired via ethernet, vnc, filetransfers, and online games all work good albeit the wireless delay, still not bad in VNC however.My AMD machine is set up for static ip at 2 of my modem goes to port 8 (uplink) of my switch.*Port 1: My server (Configured for static ip at rest are just my B&W; g3 setup for static ip at and an old P2 I believe is at .69 and a 1.5 amd athlon aswell setup on, all of those in no particular order except I made sure my server stays on port 1.I did have everything setup so my server was on port 2 of my modem all by itself, but I needed the switch over by my server so I moved it, however, I was still having these problems before hand, even when my server was running on a completely different motherboard!Also, maybe could someone tell me why my server won't boot unless I have a bootable disk in the drive (IE: my windows 2003 server install disk), just so it goes to "press any key to boot cd.......", of course I don't push any key, and it continues to boot into windows.However, if I dare start my server without that disc in there, it simply goes to "Invalid System Disk error, insert correct/valid disk (can't remember it word for word), and push enter"I've tried reinstalling windows server 03, and same deal, yet it's using the same hard disk for the OS that my previous motherboard used and booted from not a problem.I really apologize for the long post... but I've quite literally burnt myself out and lost all motivation with continuing to expand my computer network and so I figured I would ask for help on here for one last resort, but I know many people probably won't read it due to the long post, but I have a lot of problems I don't have answers for and I need to explain myself somewhat thoroughly or else I won't find the proper solution for the problem, now will I?

Topic by Punkguyta  

Im starting an ebay gadget store. what are some cool fun things to sell?

Well technically ive already started, but now, ive made enough profits to begin expanding. At the moment i sell 70mw green laser modules (not pointer pens), carbon graphite rods 5/7/10mm wide at any length and from time to time i try and get rid off my liquid a$$ stink spray, though people tend not to buy that as postage is $6, and lastly long range, but very cheap, 433mhz receiver transmitter pairs . All of this , from within australia, i plan on selling things which are awsome, as well as generally inaccessible by many australians. Currently i intent to buy up 6v spark gap ignitors , identical to those on sparkfun, different coloured laser modules, titanium to weld to my MMO anode mesht cuts, more wireless receiver/transmitter pairs, though, this time, toggle/momentary ones, currently my ones are latching, i plan on buying small shockers, and lastly, Nitrates, Aluminium powder, sulfur, and all those chems which are so hard to find in australia. Also, i will start buying more, and in larger amounts, thermochromic pigment. I also plan on building DC-DC HV converters, for charging coil gun capacitors, (based on the instructable of the same name, once i get permission to use the schematic to base my design off to sell), small shocker modules (to make taser things from), Various oscillators, like flyback ones, 3D printing services and 1W regulated 808nm burner modules. Now, ever since i discovered the spark gap ignitor wholesaler, ive been thinking, "what else could i sell thats awsome and hard to come by?", but legal too, this is ebay after all. I would really like some help in finding things which arent especially expensive or big (im not buying stuff which costs like $100 a peice), but also things you would like to see sold in your local gadget stores. Really, just anything in this general catagory, stuff which is really awsome or very hard to get, either in australia or anywhere, but not illegal. like novelty gadgets, or things which do amazing things, such as mini spy cam bugs or something. I really need help, i know what kind of things I LIKE, and want, but not what others like and want. please help me out!

Question by oldmanbeefjerky    |  last reply