I need to make the circuit that every time it charges the capacitor to a certain voltage (e.g. 5v or 12v) it discharges it
Question by Dantex | last reply
Hey, I want to make an external pulse generator, mainly so I can power a simple coilgun. I know I have to have a bunch of capacitors hooked up in parallel, but what value would be ideal? And what kind of transformer do I need? Say I use a 9v battery, how would I calculate the ouptut voltage? I know trial and error would work best for me, but I don't have any transformers lying around so I need advice on which one to get. Thanks.
Topic by Jackhole | last reply
Hi. Does anybody have an idea on how to connect a Nellcor Probe to an Ohmeda PulseOximeter? Or can anybody point me out to a pinout of the Ohmeda Pulseoximeter? Reason for this is that our hospital recently received a donation of Ohmeda machines and all we have are Nellcor Probes available.
Question by 1213441 | last reply
Ok so I have two questions. First I have a very week solar panel like it can't even power a motor I can power with a AA. I would like to know how to test how much voltage it can produce. Second I'm wondering if I could use this week solar panel to charge some little capacitors which would charge up and then discharge with enough voltage to power my motor. Would this work? thanks for your help!
Question by inconceivable1 | last reply
Hi there! I have successfully been making some LED hula-hoops but my ultimate challenge lies before me: I want to program colour-changing LEDs so that they pulse ultra-fast and appear 'white' when at standstill but leave rainbow trails when they move. I believe it to be an optical illusion caused by the pulsing... I assume this requires a PIC program but I have no idea where to start or even if I am on the right track - does anyone out there know how I might achieve this? thanking you in advance, Amelia
Topic by funkylamb | last reply
Here is my proposal. I'm building a pan/tilt unit. I plan to have a 200 step motor attached to a 20:1 worm gear, (the latter is needed so it will 'lock' in place, and not be solely reliant on the motor's holding torque.. So in order for the output shaft to turn 180 degrees needs the worm gear to turn 10 times. In turn the motor must do 10 revs, which would need 2000 pulse steps. It's the pulse generation that's proving difficult. Whilst a 555 timer could generate pulses, I want it to be 'mechanical' For example, if I turn the knob 90 degrees, I want to create 1000 pulses, (45 degrees creates 500 pulses) and so on, so the knob matches the physical position of the camera. If I turn the knob 180 degrees in 1 second ... the motor will turn 180 degrees in 1 sec. If I turn the knob slowly, pulses will be generated slowly, and the camera/motor will turn slowly. My idea at present is some sort of optical encoder ... but that would need 4000 divisions on the wheel!! Or - a 1024ppr wheel with a 1:4 step up gearing ... but such encoders are several hunderd Pounds!! And I would need two of them!! I have software that will allow me to print an encoder wheel, but resolution will have to be 'course' since it will use an LED / transistor, so I suspect around 64 divs. I purchased a RC servo, wondering if I could remove the motor, and turn the output shaft by hand. Couldn't be done. I've also considered 'planatary gears' in reverse to 'step up' the revs ... but I cannot locate any 'hobbyist' versions other than the Tamayia type. Also briefly looked at RC servos, but having done the maths, it would be impractical to get the output to move (say) 0.1 degrees as the motor would only move about 1/4 of a rev and have no torque!! (One option may be to make it continuos rev, and place a feedback pot externally.but again, moving 0.1 degree around a pot would create minimal feedback) Incidentally, 0.1 degrees is the stepper resolution 180 degrees / 2000 steps Anyone any ideas? Bearing in mind that the speed of the pulse train is dependant on how fast the control (pot) is turned, and also matches physical camera position. Encoders are preferred option as it's then possible to electronically guage which way the motor is turning. If electronic, here is (sort of) what the circuit would need to compute. (Sample and hold?) Moved from 0 to 45 degrees in one second. That degree of movement needs 500 pulses, thus need to generate a pulse width to get 500 pulses in 1 second timescale. ** This is just to give an example. The actual sampling rate would be much faster. If it was a 'slow' 1/10th second, in the above example it would check every 4.5 degrees, and generate 50 pulses in that time scale.
Question by ChrisB1957 | last reply
I am making a pulse sensor using an arduino, and I was wondering what type of arduino would be the best for this project. Here is a link to the tutorial I am basing my design off of: https://docs.google.com/a/hightechhigh.org/document/d/1FVFffuKD9OnkTOwxs3dVaxp5LYb4S1aj65MS6lvIZbA/edit?hl=en_US My goal is to make the pulse sensor as compact as possible while still able to be powered by an external power source (so it does not need to be connected to a computer to function), and as of now I have access to a traditional arduino and a lilypad arduino...which could be used to make the pulse sensor compact, while still allowing it to be powered through an external power source? Thank you!
Topic by hthnc-student
I want to make a pulse jet which will produce about 100 pounds of thrust.
I'm trying to build a model with a small remote control laser pointer aiming system. I'm not exactly a mechanical genius and, I don't want to spend over $100, or much over $30 if I can help it. I figured I could set up a simple pulley system with some cord running from the laser pointer to two small electric motors, one for right and left and another for up and down. I don't need the laser pointer to swivel 360 degrees, just about 90 vertically and horizontally would work fine. If I were to attach a few monetary switches, I would be able to run the motors one way or the other, and get the laser pointer to point wherever I want. The main problem I am having is that every electric motor I find has a RPM in the thousands. Such speed would jolt the laser to one side or the other without any means of fine adjustments in aiming. I've looked around and it seems to be the general idea that either a PWM (pulse width modulation) controller or gear box are the best options to get lower RPM out of a motor. I don't have much room to work with where I want to mount the laser pointer, so I decided to go with a PWM controller and spread the components around the model to save space. I've been doing my best to construct this.... www.discovercircuits.com/PDF-FILES/SIMPLEPWM2.pdf ... but my knowledge of circuitry is rather limited, having only take a college course on basic circuitry, I'm in a little over my head. Could someone please identify the component labeled "PULSE WIDTH ADJ" (center bottom, between the two diodes) is it two 250K resistors in series with the lead to the left acting as a resistive load or something else? Also, what is the component labeled "IRFD024" (far right below the motor) I would be very appreciative for any information that would aid me in getting a PWM controller to slow a motor down to around 50 RPM. If some one has a better idea all together, I would be willing to scrap the motors for another project and start from scratch.
Topic by cruton | last reply
Good Day, I'm new in Android and Arduino Programming. Does anyone here have an Idea how to send coinslot pulse to android app via bluetooth. The Coinslot is connected to an Arduino with Bluetooth module. and will send pulses to android app if coin is accepted. any help will be greatly appreciated. much better if with example codes. Its for school project. godbless.
Question by DJGETZ | last reply
I am a complete bigger to all magnets, electromagnets, and electronics in general. Recently I've had an interested in different electric motors and have been looking into trying to make a pulse motor that is both efficient and powerful. To do this I want to be able to have the best arrangement of the magnetic fields of the neodymium magnets on the spinning disk and the electromagnets on the outside. I started playing around with the magnetic calculator found on https://www.kjmagnetics.com/calculator.asp but I don't really know what I'm looking at, just that different shapes and sizes have different fields and strengths. Since a pulse motor is built by using an electromagnet to repel a neodymium magnet, what would be the best design for a strong burst electromagnet in the direction it's repelling the neodymium magnet? Also, what would be the best shape for the magnet to have the biggest repelling effect from the pulsing electromagnets?
Question by AlanR18
Consists of 21 blue leds connected in parallel taken from one of those cheap toy lightsabers. Before disassembly, the leds were powered by an on/off switch and 3 AA batteries. All options considered - 555 PWM, PIC, or even descrete components. Finally, circuit to be powered from 5V-9V.
Question by clint2880 | last reply
Im making a battery powered coil gun.. each coil draws about 180-200 amps of a pulsed current. I want to know what fuse ratingi should use to protect the circuit.? or if there aint such a fuse.. what gauge wire should i use as a fuse..
Question by icey.hood | last reply
Hi,I have a simple buzzer which I want to convert to an oscillating buzzer so as to obtain the sound similar to that of an automobile's reverse indicator.I've posted a schematic(borrowed from electroschematics.com) below.I intent to replace the LED with my buzzer and omit the resistor.I hope by building this circuit,to make my buzzer 'buzz'(or make noise) at an interval of 1 second(since its a 1 Hz pulse generator).Would the results be similar to my needs?
Question by Adarsh_tronix | last reply
Hello.. I built a transistor scr to turn on leds in my car from my remote.. my remote uses negative pulses to turn on and off... now the problem is that the scr needs a positive pulse to turn on but it uses negative to turn off,, so turning it off isn't a problem.. Im pretty sure I can just use a transistor to do this.. here is the schematic I used to build the scr...http://www.talkingelectronics.com/projects/TheTransistorAmplifier/TheTransistorAmplifier-P2.html#Latch ... fig 75b... is there a way to modify this circuit to make the turn-on negative or just a way to use another transistor to make my negative pulse positive? I could easily use an automotive relay to do this but im trying to make this as small as possible and its still on the breadboard.. I want to get this figured out before I put it on pcb.. thanks for your help
Topic by aclark32
I'm trying to get a crash sensor to output a single 800ms pulse when depressed and held down until it is released and repeat when depressed again, I have had this working before but cant seem to achieve it again. It either continually loops while depressed or wont output at all until it's released. Any help is greatly appreciated :)
Question by KentB2 | last reply
Hey guys, I'm trying to build a portable EMP generator, which will be powerful enough to knock out (temporarily) my neighbors stereo (if he plays it on loud at midnight again). My setup is as follows: 8 330v 160uF Capacitors wired up in series. 8 330v charging circuits for the capacitors with their outputs in series wired to the capacitors through a switch. The 8 capacitors are wired up to a coil through a switch. The coil is made from 6 gauge wire (or a 1/16" copper strip) that is coiled 5 times. I would really appreciate any feedback because this is a fairly large undertaking for me, and i'm kind of nervous at working with over 2000v of electricity. Does anyone know if you can discharge a cpapcitor by throwing it into a swimming pool???
Topic by recon506 | last reply
Hello... ive built an scr using transistors to turn on leds in my car with my remote.. my remote uses negative pulse.. now the scr(latching transistor) that ive built turns on with a positive pulse and off with negative.. so turning it off is not a problem.. I need to change the negative turn on pulse to positive to turn it on though. I know theres a simple way using a transistor to do this, but im still learning and my knowledge of transistors is still limited.. here is the schematic I used.. figure 75 b. I followed the schematic and it works just fine..http://www.talkingelectronics.com/projects/TheTransistorAmplifier/TheTransistorAmplifier-P2.html#Latch ... thanks for helping me out here
Question by aclark32 | last reply
Hi, I have a tiny solenoid from an automatic air freshener that I want to control manually. The solenoid acts as a valve that opens when fed 5v, and closed when no voltage is present. On the factory board, there's a timer that triggers the solenoid every few minutes for a fraction of a second (opens and closes so fast it just sounds like a click). What is the simplest way (No Arduino, Raspberry, etc.) to make a 5 volt pulse to make it go "click" on the push of a button? Further more, how would I control the length of the 5v pulse? I want to be able to control the amount of gas it passes (Pun intended) when activated. Any information would be helpful, and a circuit diagram would be greatly appreciated (I can read diagrams but can't design a circuit). Thanks!!!
Question by Morgantao | last reply
So i pulled out an led brake light from an old nissan spoiler that has its own circuit and resistors on the board with only + and - wires coming out. Is there any way that i could hook it up to the headphone output that i have in my current car? I know that i have to use a tip31 transistor but i dont know how to wire it up.
Question by gman15 | last reply
I need a schematic and the code for a square wave generator, with the following specs (although it is a bit specific) Repition Rate (external trigger, 20 Hz 200 Hz 2KHz 20 KHz 2 Mhz and 5 MHz) controlled by a rotory switch. a vernier (pot) controlling pulses per second.) a single shot button (N.O. push button) external trigger (BNC Connector) Delay (Rotary Switch) .1, 1, 10, 100, 1k, and 10k microseconds Vernier (pot) for the delay a sync output (BNC Connector) with a toggle switch for polarity. double or single pulse on the output (toggle switch) polarity selection on the output (toggle switch) gate on off (BNC connector and toggle switch) 10db step (on or off toggle) 50 ohm load on or off (toggle switch) rise and fall time (pot) Any help would be greatly appreciated, as this is a bit specific. I only need a schematic, and everything else i can take care of. Once again, Thanks for the help.
Question by mchp82 | last reply
I love to graph things. Everything from outside temperature to server room temperature to the number of users on the network to my weight.I just read an article in Make magazine about DIY ECGs, and it got me thinking.. i want to graph more things about my body :)Would a microphone embedded in the bed be able to pick up the heart beats and calculate the BPM? This way I could graph development in resting heart rate over time. The microphone would pick up lots of noise from the person moving around etc.. but that doesn't mather. It only needs to get a few clean heart beats in order to calculate the bpm, right?What hardware and software would be suitable to create something like this?Any ideas?Yeah, of course there are other more traditional ways of measuring heart beat.. but I'm to lazy to do that.. I'd rather spend some time making a fully automagickal system.
Topic by chr | last reply
Question by tanujlife | last reply
I want to turn a garage door opener into a remote relay because i have a million and one uses for it, but when the sensor senses the signal, it activates the internal relay for a second or two, i want to know if or how i can turn that into a toggle output so when i press the button it turns the rely on if it's off and vice versa. if i need to mod the receiver circuit that's great, but i also plan on using this for a proximity sensor: http://www.ikalogic.com/ir_prox_sensors.phpand if anyone can tell me how to use a 4013 or something like that to do this, i can kill 2 birds with one stone. thanks in advance!
Question by the judge | last reply
Hi! I have a project that needs to sense whether water is flowing through a pipe. I bought a water flow sensor on Amazon (https://www.amazon.com/gp/product/B01LVWHJP0/) thinking I could use it as a basic switch, however, it's got a hall effect sensor and I don't understand how to deal with the voltage output. Measuring from the pulse signal to ground, the sensor swaps the polarity each time it's triggered: With water running, I see a positive voltage. Turn the water off and back on, voltage goes negative. My control system can't deal with this. What I need is a simple circuit to turn the sensor's pulse output into a contact closure. Can anyone help? Thank you!
Topic by rpdubz | last reply
Forgive my ignorance on the actual name of these circuits. The circuits I am talking about are those that receive one momentary signal, and then perform a whole series of tasks, without the use of a microcontroller. Thanks!
Question by mad magoo | last reply
For video diagnostics, a wave-form monitor and a pulse-cross monitor are highly useful tools. Is there a simple way to convert a standard video monitor into a pulse-cross (sometimes called a cross-pulse) monitor? I.e., feed the signal into a box and the box feeds into a standard video monitor and you can see the normally invisible image corners and invisible vertical interval of the video. I think this can be a simple electronics diagram. Thanks for any help!
Question by LightSpeed1 | last reply
I need to toggle a solenoid between 2 positions. It isn't spring loaded so needs to be powered between states i.e. a +6v and GND pulse to the coil then wait 5 to 10 sec's before sending another pulse but with the polarity reversed. Simple to do with a 'Mom-OFF-Mom' double pole double throw toggle switch e.g. JAYCAR Switch Tgl Mini CTR-OFF DPDT MOM CAT.NO: ST0358 but I would like to be a bit more automated. Ideally the cycle will start at power on and then automatically repeat every 30 min's or so but if that makes it too complex, then a momentary push button switch could be included to manually initiate the cycle.
Question by DavidB687 | last reply
Question by wizzywoo | last reply
uhi i want to generate 3 equal variable pulse high with constant pulse low signal that vary with potentiometer and asume it repeat it self every 10us and pulse min is constant 2u and pulse high vary betwwen 5-8u and i want it to carried at specific frequency? i attach the signal i want to generatel
Question by britich | last reply
Here's an interesting idea. It may be possible to control two servos independently with only one output pin and an inverter/NOT-gate. Normally, a servo is at its 'center' position when a pulse is 1.5 ms & its angle (or speed for continuous servos) is based on the difference between the length of time of the pulse it received & the base-time of 1.5ms. The servo itself does not react to the time BETWEEN pulses however. If the signal was inverted, the result would be a pulse with a time being that of the time between pulses of the initial signal. If the width of a pulse and the time between pulses can be independently controlled, then it would be possible to control one servo with the signal directly, and another servo using the inverted signal. I found something similar here [http://www.diyrc.com/reversers.htm] but it seems to be intended for 'reversing' the signal used to control one of the servos.
Topic by Michael_Everett_Feder | last reply
I want to make a pulsing red light to insert into a sculpture project. The finished piece will be about 2' x 2'. They all need to pulse at the same time for the same duration, fade in fade out type scenario. I want the lights to be pretty bright, where do I start?
Question by dangitalltoheck | last reply
I am making a project using an alarm clock, and basically for this part, I am trying to make the alarm turn on an array of leds and I have it working, I have the voltage regulated right and everything, I just need to know how to make the leds stay lit instead of turn on and off with the pulse of the alarm... I thought that I could do it with a capacitor but I haven't figured it out yet... Thanks
Question by arhodes18 | last reply
This mosfet is rated at 110A continuous/390 pulsed 55V with a Vgs of ± 20.. i have a coil that draws about 200amp pulsed current.. thanx
Question by icey.hood | last reply
I have a 2khz lm358 square wave generator i want to boost it to 16-25khz max can someone tell me how link is item plus circuit diagram::: http://www.ebay.com/itm/Pulse-Upgrade-LM358-Duty-Cycle-Frequency-Adjustable-Square-Wave-Module-NE555-/221623454225?hash=item3399c98a11:g:o70AAOSwD0lUfVW5
Question by TheGreatResistor | last reply
For my application , I need to generate a signal wich contains 2 pulses , 1 of 150 ms and the other of 427 ms , seperated with a duration of X ms , using the usb port of my computer and c#
Question by isalhi | last reply
I have a paper model of "Sleeping Beauty Castle" of Disneyland. I got this model from disneyexperience.com and I need to make the lighting on the castle exactly or like the one at Disney during their firework shows.Now I'd like to place the LEDs around the perimeter of the inside of the castle. The perimeter meaning the space in between the castle and the pink top part of the castle. I want to know if you guys know how to program them to change color fade and do other effects and to synchronize the lights to music. And not just flashing or pulsing to music, but being part of it...just like the one at Disneyland. I'd also like to have a dimming effect on it too. And the LEDS will be 7 color changing ones. ANY help would be gladly appreciated. THANK YOU. Please let me know if you need anything on my end.
Question by ray33 | last reply
I'm making a gas mask for my Resident Evil Umbrella Soldier Costume for Halloween but stuck at the LED part. I have the 'Getting Started with Arduino Kit' (seen here: http://www.makershed.com/products/getting-started-with-arduino-kit-v3-0?gclid=CjwKEAjw456hBRDQ4eqg8MzA2W0SJABI2gJ8cIMUx4P7s-7_auRaly1jAeWzXCQwuYyWBtimS1twpBoCwXfw_wcB) which you can see the contents on the link but I'll post it here: (1) Arduino UNO (1) USB Cable (1) 9V Battery Pack w/DC Plug (requires soldering) (1) Clear Breadboard (1) Deluxe Jumper Wires (2) Red LEDs (2) Green LEDs (2) Blue LEDs (1) RGB LED (10) 10K Ohm Resistors (10) 220 Ohm Resistors (10) 270 Ohm Resistors (2) Photo Resistors (2) Momentary Button The mask in question is in the image posted below. That's what I have done so far. I want to have the 8 white LEDs fade out while the other 8 red LEDs fade on and vice versa when I turn the mask on. The timer would be a count of normal breathe basically and just continue as such. I'm new to LEDs and all of this in general so I was wondering if it's even possible to make with what I have in the kit. If not, what else would I need? Any suggestions for tutorials I can look it on how to accomplish this? Thanks.
Question by Doitourselves | last reply
I would like to make a Pulsed diode array: 810 nm for my own use, but have not been able to find any schematics on how to do so. Can any one help me in building this unit?
Hi All, question from a newbie. I'm working on a project for my (steampunk) daughter. For part of it I've taken the flash circuit from a disposable camera (PDF 1:Flash+MechanicalTrigger). This works just fine when I close the trigger mechanically. What I want to do is trigger it with the same pulse (from a 555 timer) that I'll be using to do other things at the same time. To this end I added a transistor as shown in PDF 2:Flash with transistorTrigger. My intention is to feed the 555 pulse to base, saturating it and triggering the flash. Result, abject failure. Help! The proposed triggering transistor is an MJE340(NPN). When set up as shown the indicator LED glows but voltage across Emitter-Base produces no result. When testing I noticed that if I mechanically make the collector-transformer connection it triggers a flash, even with no voltage across emitter-base. I'm stumped. Any ideas very gratefully accepted. Thanks, Fred.
Topic by fredstein | last reply
I need a circuit that will give just a few pulses..... starting with a few seconds of "ZERO"...a long "one"... Then three quick pulses.... then end with a constant "ONE" . I have tried using a binary counter circuit and led's, but my design abilities are somewhat lacking. I don't know how to use microcontrollers so that won't help. I was hoping for some kind of IC that has input pins that can be grounded or diodes attached. Then the IC would scan those parallel pins and send out the serial pulses as described. I need this to activate another circuit at work for my boss. I am good at building electronic circuits but not so great at designing them. Thanks in advance for your help.
Question by framistan | last reply
Hello World,I am currently making a circuit that will produce a single pulse using Arduino. I want that my circuit and code should produce a single pulse, after that the pin o which I am taking output becomes low until I switch off the button. the pulse should again be generated when the button is pressed.I have been using a series of codes. But, whenever I upload the sketch to the Arduino it works for once. after that when I switch the button off and turn it on again it doesn't work. If the switch is kept on after some time it again starts to generate a pulse.Please if anyone can help me out would be a great thing.Thankyou.
Question by shubhamnagla909 | last reply