inline volume control

Hi im ramanta from indonesia i try to add an aux in to my old boombox, the reference from here https://cocodrilabs.wordpress.com/2012/04/05/installing-an-auxiliary-input-on-a-stereo/ i already got it working, but the problem is the potentiometer(volume). Only one channels work my boombox has 2 IC Amp, one for each channel. I already try to connect the source(ipod) directly to the amp (without the pots), work like a charm. But the sound is too loud and distorted

Topic by ramanta 


I'm looking for a small inline vent (1-1.5") to ventilate a small box

I found only 4" and bigger vents (such as:                      http://www.hrpworld.com/index.cfm?tpc=Inline_Duct_Blowers&form;_prod_id=59,7_73&action;=product                       http://forums.bimmerforums.com/forum/showthread.php?t=1207814) I need to place equipment which heats up quickly and I want to blow the air outside. The hole I can drill is 1"-1.5". Any help will be greatly appreciated.

Question by nilovich   |  last reply


What are they

Anybody know what the little single in line components are (not the ICs in plastic cases.)Mine are blue

Topic by gimmelotsarobots   |  last reply


Inline out door amplifier

Okay i posted a while back about a project that I was converting my cd boom box into a mp3 back pack but after tranfering the it into another case it is still to big. I did wire the speaker though to a 305mm phone jack and found that if I pluged them straight ot my ipod that it gave sound, so what i need to do id buil a mini inline amp that runs on batteries so that it can boost the signal to make it louder for the speakers. Any Ideas?

Topic by iathon   |  last reply


water inline low pressure gauge at output

I don't know if they sell them , water Inline  pressure Gauge  made for 5 lbs and under, or is there an easy way t to make one, doesn't have to be inliine, it just needs to  measure the psi at 5 gallons and at 1 gallon.. Even A balloon that burst at 3psi would be good/. it is for a medical device. i spent the last year going crazy cause it was defective brand new.  it was putting out the correct  pressure at the start, 5 gallons, at the half way point it was putting out about half the pressure, didn't know it, almost had  surgery because of the poor results thanks for any ideas

Topic by escapefromyonkers   |  last reply


Why doesn't my RF inline dimmer activate LED strips when powered by a car battery?

I built a 12VDC, 2A lighting system in my truck topper to run off my engine's battery and it works fine unless I add an inline RF dimmer and then it doesn't respond. When the same system is powered by a separate transformer that receives 120VAC and provides 12VDC, 3A the RF dimmer works fine. Any idea how to solve this problem? The system is built with these parts: LED strips amzn.com/B00HSF66JO RF dimmer amzn.com/B00MHKCTLE LED strip transformer amzn.com/B00DKSI0S8

Question by NickD163   |  last reply


anyone have pinouts for a inline mic earbuds?? like the skullcandy ink'd??? im working on a project for my xbox 360 :)? Answered

Well ok so i bought skullcandy ink'd earbuds and i noticed that they have an inline mic which is really really cool cause it works really well with calls and as soon as my call is done i go back to listening to my music :3...and all of a sudden it hit me! what if i can use these same earbuds (with a little modding and soddering) for gaming and chatting just like a regular standard xbox microphone!? and even with game audio too! so i can hear everything that's going on around me also! =D once im finnished i can post the instructable for everyone to see since i had such a hard time finding the information cause no one really came up with this (as far as i know)  and make it easy for anyone else who wants to try it :) all im asking for is the pinouts (what the little rings on the plug do) and ill have most of the information i need to start lol thanks for taking the time to read this!! any help would be really really appreciated :3

Question by brivera-1   |  last reply


Best sub $20 in ear headphones with GREAT bass? Answered

Looking for some headphones to replace my Skullcandy buds that broke... I want something with great bass- something that really punches. Preferably with inline volume control- I am using an ipod touch (really love the volume control). I have a pretty small budget, around $20 is my goal, but as I am not an audiophile, they don't need to be perfect :) Just in ear headphones with great bass.

Question by astroboy907   |  last reply


What comment engine does instructables use?

I like the way it manages comments. It is sort of like an inline forum. Is it made by the instructables team? Is is propriety? Is it open source? Is there something similar?

Question by munchman   |  last reply


What are these? Answered

I came across about 100 of these, I am not sure if they are photodiodes or LEDs would like to use them for something!  Have tried them at alot of different voltages, they all have a resistor inline with them which makes me think they are LEDs not sure on operating voltage. they also have a glass lens. markings - mexico 1150

Question by mutantpoptart   |  last reply


High/Low light LED switch

I recently purchase some 3528 300p LED Strip Light so that I can make some under cabinet lighting. I wanted to make my own because I believe I can to it for a much better price and learn something in the process rather than buying an LED light set from a big box retailer. I have a 3 position rocker switch Off/high/low. If possible I would like to use the LED lights in a High/Low configuration. From what I read they make PWM modules that control the LED making them appear to be dimmable, but I do not want to use one of these devices. For the low setting I was considering wiring in a POT or an inline resistor to drop the Voltage to the LED's. On second thought I suspect that this would not work and if I drop the voltage too low this would result in inoperable LED's. By the way I would not be opposed using an inline resistor if this is a good way to reduce the light level Is there some cheap electronic component that will produce or simulate an approximate 50% PWM that I can wire inline with the switch, in effect producing a low lighting mode? I am not interested in using a variable PWM control, I just want to achieve a switchable high/low lighting. I am not familiar with components and I hope you could suggest a few ideas for my project. Some details: The led strip will be ~11 linear ft using 12VDC and about 40W of electricity.

Question by baudeagle   |  last reply


In the process of hacking the rather cheaply made RS digital voice recorder I bought recently...

Remember the pic of the voice recorder I had in my April Fools entry ? It looked like the first pic below. It uses a cheap speaker for both speaker and mic. The sound from it is less then desirable, but not because of the chip used, but because costs were cut by using the speaker instead of a decent little Electret mic :-( Well, I have started to work on changing this (as it was unusable as it was): I first soldered in a little mic from an old dictation machine (yeah, it used reel tapes) and this helped. But I wanted it to be more under my control, so I added a switch inline to the mic. Now the sound is great, but it is still barely audible, so the next step is to make a 5X or 10X amp for the playback. I might even get ambitious and put a preamp inline with the mic. This I have been working on in my "spare time" and also hope to get a CAKE (torte) entered into the contest on Monday.....busy busy busy :-)

Topic by Goodhart   |  last reply


How to wire in an extra car horn with a switch on the dash?

Hello! I have an extra car horn and I need to install it into my car alongside my other horn, and I have no idea how to wire it! Here is what I have: a Car horn with two wires (black and red, and red) 16G wire, a switch, and a inline fuse. I need to know how to wire it to the battery, and how to ground it. Does anyone have any experience with this? Any help would be greatly appreciated. 

Question by noahwinter357   |  last reply


How can I make an ammeter for ~5V DC up to 3A? I want to connect this ammeter to a microcontroller.

I want to connect this ammeter to a microcontroller ADC and display it on 7-segment displays. I guess a 10W resistor ~0.1ohms or something will be involved. I can obtain them easily. I want to make an inline USB ammeter. I am experienced with PICAXE microcontrollers and surface-mount.

Question by jdorne   |  last reply


how can i use a generator with a 72v electric bike?

I read the article on how to make a 72v electric bike and a 96v electric bike and i was wondering if we could place another 72v motor inline with the main ( so when 1 motor rotates the othere also rotates at same speed producing electricity )and use the 2nd as a generator to charge the battery . if we could use a diode in the circuit so as to make the current flow from the 2nd motor to battery and not the other way.

Question by jona6664   |  last reply


Capasitive start and run.?

I have build this circuit and works great for a 12v pc fan on the bench for PWM. When i hooked this into my ATX power supply to regulate the fan speed the fan doesn't like to run unless i touch some portion of the pcb i build the circuit on. I spliced the wires from the ATX power supply into the PWM circuit, then out of the PWM circuit back to the fan. I guess its a  capactive issue. What could be the fix for this? The other An EE suggested i add several diodes inline to slow the fan down....hhmm maybe

Question by WWC   |  last reply


Question about using LiPo Batteries

Hello, I would like to use a 3V Solar cell rated at 45mA to charge a LiPo Battery (3.7V) rated at 200mAh. am wondering. How long should I allow this to sit in direct sunlight to charge without overcharging the battery? I would also be adding an inline switch to shut off current from the solar cell. Here are the links to the products I would be buying (In case it helps) Solar Cell: (Its about half way down labeled "3.0V 45mA Solar Cell") https://www.futurlec.com/Solar_Cell.shtml Battery (Note I'm only using one) http://www.ebay.com/itm/2x-3-7V-240mAh-30C-Li-Poly-LiPo-Battery-Pack-For-RC-Micro-Helicopter-Air-plane-/300715147936?pt=Radio_Control_Parts_Accessories&hash;=item46040502a0 Thanks

Question by Tuckoguy   |  last reply


I want to build a voice changer that takes its input from a line out?

Hi I want to build an "in-line" voice changer. There are loads of kits and devices to build one that takes input from a microphone but I cannot find an inline one at a sensible price. I bought a Vellman kit - but this too has an on board mini microphone. https://www.velleman.eu/downloads/0/minikits/manuals/manual_mk171.pdf   I was considering just replacing the mic with a line-in socket. I will also attach a line out socket to the speaker output pins. I have done some reading and it appears as if: The mic output will be a few millivolts. The line input will be 1-1.5v So looks like something will go phut. Can I just put a resistor in line with the line-in socket - and if so what size? Any other thoughts on how I can do this with hardware (not software). Many thanks Steve

Question by SteveM290   |  last reply


Wiring a 2 way radio headset to also record audio?

I am a hang glider pilot and like to take videos during flights. I would like to add narration and the back and forth communication with my chase driver as part of that. I have a headset in my helmet that is wired to a ham radio for that communication. The jack to the helmet is a three conductor, 1/8" jack that goes to the earphones, microphone and a common ground. There is a push to talk switch that trips the radio to transmit which is between the helmet and the radio. What I would like to be able to do is put a jack/splitter inline with the existing jack to then go into the mic jack on a voice recorder to get three things; Radio audio (receive), Radio audio (transmit) and me just talking into the headset mic - Narration.Not sure how well I am explaining this and I could just experiment, but I am thinking it's not as simple as just wiring stuff together. I'm good with a soldering iron, but no EE by a long stretch. Any thoughts? Thanks

Question by hang4   |  last reply


DC power logging, or at least measuring (for solar panel & devices)

I have searched and searched, but I can't seem to find what I need. I want to be able to log power and plot a V-I graph and a P-t graph. I was picturing tapping into an iphone charge cable (for example) and wiring in connections. Here, I could connect the device, so that when i connect the phone via charging usb cable, current runs through the device and is measured, and voltage is read from inlet of the device to gnd. Do these exist? I'd like to also use it for a solar panel (putting a big wire loop resistor for a load to draw max power) so that I could see where the power tops out, what voltage is yielded when the max current is drawn, etc. It would be nice to be able to plot data points in excel for example. Any idea? Even if I can't LOG the data, I'd like to be able to read instant power use, not just V and A. I've seen the inline USB meters that do that. Anything helps! Thank you!

Topic by Phoenix17   |  last reply


SCR latching circuits and LEDs

LEDs and I just can get along...In another project I had a solenoid blowing out LEDs. Now this: I have a number of switches hooked up so they trigger an SCR latching circuit to turn on (and keep on) some LEDs. The SCRs are wired in parallel to each other and have a 1K resistor on the gate. Power is applied to the whole circuit via a timer relay (not hooked to the SCRs). The power is a 12v, 200mA wall wart. And the SCRs I'm using are NTE 5465. The LEDs last a while but burn out or go to a weird blinking state (when the switch is depressed) after about 2-3 days. In my previous project I needed a diode to help with the solenoid voltage spike. But I don't think that it is the case for this project since the SCRs aren't inductive. Do LEDs connected to the switch part of a relay need a diode too? The LED package I'm using is purchased from Happ Controls (see hideous grainy picture). It's rated for 12V but they can't give me a mA rating on them. But they say that no inline resistor is required. Any thoughts? I think this is another case of my inexperience causing me to overlook the obvious.

Topic by robotninjasquid   |  last reply


Modifying LED puck lights

I apologize in advance for the complicated question, but here we go. I have wireless puck lights that work off either pushing the top to click on, or a wireless switch. The switch only controls on and off, no color control or brightness. The lights run off 3 AAA batteries per puck. My problem (which seems to be the most common problem with these puck lights) is that they drain the batteries even when off. I have a feeling the drain is due to the wireless antenna staying open to receive the signal from the switch. I found using a 5V USB plug powers them fine, but I don't want any draw to occur when the lights are off. So my 2 questions are... 1. Has anyone encountered a device like this and found a way to disable or even remove the wireless antenna only allowing the LEDs to work off the internal switch? 2. Does anyone know a way to bypass the switch so the lights are powered when power is present? My goal is to have the lights run off the 5V adapter with an inline switch to control the line up. vs. clicking each light on one at a time. I have attached images of the board top and bottom, also the lights are "Lightmates LED Wireless Puck Lights" notorious for eating batteries.

Question by NathanA52   |  last reply


Modifying ATX Power Supply for 12v Power - Easiest Method?

I'm building a small box with toggle switches on it. I want each toggle switches to turn on something simple (mostly just LED lights). I was trying to think of how to power the box, and I thought about using an old atx case power supply since I've got an old computer I could pull it out of. I'm seeking advice because I have no experience with wiring at all.. and I don't want to burn the house down. :) If I jump the green and black wires on the motherboard plug so that I can turn on the supply, couldn't I just buy a simple molex Y-splitter and plug it into an available molex plug, and then cut the yellow and black wires and use those for the power and ground? Here are the Y-splitters I'm referring to: http://www.amazon.com/Computer-Molex-Power-Supply-Splitter/dp/B001PI9AAC Cut off the plugs from the Y, and run the yellow and black wires to my switch and then run a power wire from the switch to the LED light or case fan or whatever I'm powering off of that switch. The switches I'm using are 12v automotive toggle switches. Would this provide the power I need? Would it be too much power? Should I put in an inline fuse or a ohm resistor or something to make it safer? I appreciate any opinions.. I'm curious if anyone has ever used a molex plug in this kind of way and how it worked. :)

Topic by dlister70   |  last reply


URGENT! Question about in-line audio control between amp and speakers? Answered

I have a unique project that I am almost finished with, but need to make one last adjustment to. I am running a 3.7W Class D Audio Amplifier. The amp has two outputs. I need one to run as designed (controlled by my iphone before the signal gets to the amp which will be set to almost max volume). I need to then control the other output channel to reduce the volume. Any suggestions? It seems like I might be able to just get an inline control out of an old set of earphones, but I am not entirely sure. I always assumed (and pardon my ignorance if this was a foolish assumption) that the buttons in my iphone earbuds actually signal the phone to change the volume, and isn't really "in-line". So, I don't think those would work. Would an old set from Goodwill work for this? I have seen posts where others are asking similar questions and the answer seems to be a 1K Ohm Pot (which are apparently really tough to find). Since I have a 3.7W amp, perhaps a 10K Ohm Pot will work (people have said this doesn't work well for their headphones).  To summarize: 1) Will adjusting one output channel on a two-channel amp work? (or will the increased resistance simply close off the channel and pump all the signal to the other channel?) 2) If this will work, can I use a 10K Pot? 3) If not, will an old-school in-line volume control from some headphones work? Sorry for all the info...trying to be thorough! Thanks a ton for any advice!

Question by WhiteTyrone   |  last reply


Where do the leads of a zener diode connect to in a DC system? Answered

I have a light in my car that takes two incandescent type light bulbs, but when I use both sockets, the bulbs are broken open and some of the glass is melted in a couple weeks. I've bought plug and play LED lights that have multiple LEDs (with a resistor on both the cathode and anode) and just plug into the sockets, and I used both sockets, they lasted about two months. And since I had only one spare bulb in my center console, I plugged it in, and its been working for over a year (this is where I found out that using both sockets made the lights fail). I'm guessing that the when the engine starts, it sends a surge to the light. So I decided, that I'll just make my own light using LEDs, I have everything resistors LEDs and wire, but I'm unsure where to connect a zener diode/s to the LED array (or if a zener diode would even protect the array). I've looked on the net, but some say to solder inline and some say it needs to connect to the ground, and I cant tell which is right for my case. I've included the output of the LED calculator and the specs. below.     Source:                     12V     Diode Forward:       1.8     Diode Amps.:          20mA     Number in Series: 24    Solution 0: 6 x 4 array uses 24 LEDs exactly +----|>|----|>|----|>|----|>|----|>|----|>|---///----+ R = 68 ohms +----|>|----|>|----|>|----|>|----|>|----|>|---///----+ R = 68 ohms +----|>|----|>|----|>|----|>|----|>|----|>|---///----+ R = 68 ohms +----|>|----|>|----|>|----|>|----|>|----|>|---///----+ R = 68 ohms The wizard says: In solution 0: *each 68 ohm resistor dissipates 27.2 mW *the wizard thinks ¼W resistors are fine for your application *together, all resistors dissipate 108.8 mW together, *the diodes dissipate 864 mW total power dissipated by the array is 972.8 mW *the array draws current of 80 mA from the source.

Question by LuciferTengu   |  last reply


Heat gun mod question

I am not an electrician but I like to tinker. I am just getting started with DIY type electronics kits and I have decent soldering skills. I cant say I am an expert at reading prints, but I can usually build a simple schmatic. I wish to disassemble a heat gun for parts and add in a potentiometer to vary the heat, another potentiometer to control the airflow, and a digital temperature probe with temp display. I am attempting to build a heat generating device with precise control of the temperature and airflow. I dont really want to spend $150 on a fancy LED digital display heat gun with variable heat dial, so this is my next option and potentially a heck of a lot more fun. Initially I just want to get the variable heat and airflow control(potentiometers) hooked up, and if it will be easy enough I can later install the temp display. I could always just use a cheap "laser" temp probe to check the temp and ensure it is fairly stable. The heat gun I am looking at is a piece of junk and it only has 2 temp settings. How easy is it to install a potentiometer for varying the heat and one for the airflow? I assume I can just install the one for heat control inline after the circuit that sets the maximum heat level and dial in the temp I want. As for the airflow control I assume I could do the same thing, but instead put it before the power lead feeding the fan. I am not an electrical engineer so I want to make sure this will work first before I fry my cheapo $20 heat gun. Would it be bettter to just gut the entire thing and work with the naked parts and install my own circuit to control and display the temp or could I keep the basic unit intact and mod from there? Any ideas, or a basic schematic that would satisfy this requirement would be greatly appreciated.

Topic by RokGoblin   |  last reply


12V car battery indicator

Hi, I have been trying to design a circuit to monitor my 12V leisure car battery, I'm thinking this should be fairly simple, but its been years since I did any real electronics. So the basic idea: Use the circular bargraph to indicate the level of the battery when a momentary push button is pressed the circular LED bar graph: https://www.sparkfun.com/products/11492 So the range of the battery would be something like 10.5V to 13.5V, there are 32 LEDs in pairs, so essentially 16. 1. So if we take the first LED pair, this should illuminate when less than 10.5V, so that should be easy, as long as there is some life in the battery it should illuminate 2. The next LED should only illuminate at the next step, 16 LEDs, 3V range 16/3= steps of 0.2V So at the following steps: 10.5, 10.7, 10.9, 11.1, 11.3, 11.5, 11.7, 11.9, 12.1, 12.3, 12.5, 12.7, 12.9, 13.1, 13.3, 13.5. So for 10.7V I guess I should use resistor before each LED. 3. The LEDs should light up after a momentary push switch is triggered, I would like this to be graceful, so the ring lights up smoothly one LED at a time as the voltage increases, I guess capacitors between the resistors and LEDs? This is the simplest way I can think of doing it, I have seen circuits which use a LM339 chip, but that can only monitor 4 voltages, perhaps 4 of these in series could do the job? http://www.electroschematics.com/7068/lm339-lm239-lm2901-datasheet/ I think this is the way to go rather than using inline resistor/ capacitor pairs? So I am a clear novice when it comes to electronics (but I'm enthusiastic), so if anyone can help me with this I would be more than happy to put together an instructables how to, something similar has been done before: https://www.instructables.com/id/Car-battery-tester/ In that example only one bar is lit, I want the other bars to stay lit. I can use Eagle to make the PCB diagram and get it printed, but I need to figure out what components I need and how to do it! Thanks for any help. Gary

Topic by garynobles   |  last reply


Need advice for adding aux-in/line-in to Philips AE2160/00-A AM/MW/LW portable radio

Hey there, this is my first post! :) I'm from Germany, so please excuse my grammar! :D The reason why I'm opening up this new topic is, I didn't find any instructable or guide on how to add an aux-in/line-in to my simple mono AM/MW/LW radio Philips AE2160/00-A. There's not much to find out about the technical specifications besides the standard product information: Tuner • Analogue tuning • Wave ranges FM 87.5 - 108 MHz MW 525 - 1606.5 kHz /04 LW 150 -255 kHz /00c FM/MW /04 FM/MW/LW /05 FM/MW/LW • Ferroceptor for MW (and LW) • Telescopic aerial for FM (and SW) Amplifier • Max. output power 300 mW RMS • Tone control Music /News Sound system • Loud speaker 100 mm • Metal grill Power supply • External supply /00c, /04 230V /05 240V AC • Batteries 2 x 1.5V , type R20/D cell/UM1 Connections • Headphone socket 3.5mm General • Material Polystyrene, metal grill • Weight (g) 520 • Dimensions (mm) 210 W x 150H Here's a link to a photo of the device: http://images.philips.com/is/image/PhilipsConsumer/AE2160_00-_FP-global-001?wid=2000&hei;=2000&$jpglarge$ I didn't even find schematics/circuit diagrams for this or a similar device. There are lots of tutorials on how to add such an input to a car radio or a boombox/stereo cassette player a.s.o., but not for a simple AM/MW/LW radio. My questions are: 1.) Are there any similar hack projects here in the step-by-step or forum section? 2.) How do I find the right connector or place to solder a 2-way-switch between the sections (tuner, amp, speaker)? After the hacking job, it should be possible to switch between normal radio listening mode and aux-in/line-in mode from an external mp3 player, notebook, a.s.o.. 3.) Is there anything else to know for this project? Yesterday I've opened up the case for the first time and looked over the circuit board and the connections. I had no cam to take pictures, but I try to take some mobile phone cam pictures of the circuitry and parts at the next opportunity! Cheers, arok1

Topic by arok1   |  last reply


Solar "Generator"

Since I've always wanted to do something like this and I found this site, it's about to happen! I found a smaller version with what I wanted to do at Popular Science but I want to do something on a larger scale. I do have some questions though that I'm hoping someone can answer or point me in the correct direction.I'm going to describe what I'm doing with what and what I have questions with.I'm going to be buying this solar panel and charge controller kit. Sunforce Solar Panel With Charge ControllerA deep cycle 115 AMP Hour 12 V marine battery from Wal-Mart with Plastic Battery caseSalvaged wood Toy BoxMeter Question: How to meter how many amp hours I have left or how charged the battery is? What kind of meter to buy? Where? (not too expensive <20 bucks or so) how to hook it up.A 12 V accessory outlet with on off switch Question: I'm putting an inline fuse before the switch, 15A the line fuse goes on the + (positive) side correct?A 700 Watt 6.25 AMP DC to AC converter with 4 outlets connected to it. Question: can I put a breaker or fuse between the 4 outlets I'm going to be plugging into on the outside and the plug being plugged into the DC to AC converter? If so how?USB ports for charging with on off switch. Question: how do I convert the 12V to 5V in an easy way? I've seen some creative ideas on here for charging VIA salvaged USB ports but I don't want to have to hook it up to my power inverter if I don't have to. Cooling/ventilation for the entire thing. Any ideas how I might cool/vent it? Currently I'm thinking of using old computer fans and put them on both sides of the toy box and have 2 blowing and 2 blowing out. Having the fans run off of the solar panel during the day and either have a switch to change it to battery at night (if it's too warm in the house) or maybe photo sense it? Temp sensor to turn it on and off? Or a switch to turn it off completely. I'm just looking for idea's to keep the battery (and to expand to be more than one battery) cool/ventilated. If you have examples or detailed description on how to do it that'd be great. I'm not one to steal ideas so I'll credit the idea's I'm given if I use them =)I'm going to see how much I can run off of this and how long. Hopefully save some big time energy also!Thanks all!

Topic by oddie1212   |  last reply


DIY dimmable multichannel LED powersupply/driver help

OK I was looking in to replacing my T5 lighting over my reef tank to LED.  LED's are apparently more efficient, blah blah blah.  They appeal to me because of the DIY element, I can customize my color scheme pretty much however I want it.  I did some sciencing and some mathing and I figured out how many LED's I would need for my tank.  I knew that I would need some sort of power supply to hook these up to to power them.  That's when I discovered all the little things I had to buy to power my LED's.  The different colors require different voltages, and have different mA's so they have to be seperated to similar channels, or have multiple drivers operating at different voltages.  The dimmable counterparts of these devices cost more money,  and then I have to decide between analog or PWM, and then actually buy potentiometers(more money).  Which just leaves me to want to just make one on my own.  But I'm going to need some help.  I know the volts and currents required of my LED's, but I don't know what parts(resistors and things) I will need to get from the wall to my lit up LEDs. I imagine I'll need to get some sort of a power supply or adapter that plugs into the wall.  From there I'll need to convert the voltage from AC to DC. Then a controller for each channel.  Each channel contains an inline dimmer and LED's.(6 channels) with a max of 50v. I'll need to print at the very least two circuit boards and make a housing for each. I've attached a diagram.  It includes the electric potential and electric current requirements for each channel and gives image to my post.      This is all I can do.  I don't know what I need to make this, and I need help.  Please reply. Edit 1.: OK so I guess I need a rectifier to convert to direct current then I need capacitor(s) (don't know how many or of what value? I don't even know what value capacitors come in) to smooth out the current, and then I need voltage regulators on each channel.  however, I do think that since I want my channels dimmable that having potentiometers might do the same thing. With the different channels coming from one power source, I'm not sure how to make them independently dimmable(and varying in mA and v) without affecting each other.

Topic by stryke297   |  last reply


How To Turbo-Charge My LED Light String

I am new to electronics, but I have an idea and hope that it’s simple enough for some of you with more experience can tell me I’m either on the right track, or complete wasting my time. I have looked at a number of basic solar light / charger circuits in here and on the Web, and have a very basic grasp of how they work, but the intricacies and exceptions are still fuzzy to me.  I don’t want to recreate the circuits, and want minimal soldering since I’m new to that too. I have a 40 foot long string of 100 LED solar lights that are driven off of one hard-wired AA Ni-MH 1200mah battery.  There are three ideas I have to supercharge the string to improve it.  Without tracing through the existing circuit (which I may not understand anyway), I want to draw on your experience before I get too involved. If I ultimately need to pull things apart and try and trace the circuit, I will, but until then, your guidance would be appreciated. I would like to: A) Remove the old battery and add a larger capacity battery since I currently get maybe three hours of light.  Probably easily done. 1. Changing the battery to a larger capacity looks straightforward.  I will be adding a D cell (if it fits the case) NI-CD with 3000-5000mah (not purchased yet).  Since the cell is the same voltage, can I assume that the swap doesn’t really affect the circuit? B) Add another solar panel.  Probably easily done.  1. I have one small solar panel that came with the unit which feeds the existing battery.  I am assuming that it is 2v (to suit the AA battery) and based on the size, I am assuming that it is between 100 and 150ma peak output.  I would like to add another small panel that I have lying around that is rated 2V / 150ma.  Installing these in parallel should give me a higher energy input, but still at the 2v. Looking at the circuit board the solar panel goes to the board before the battery.  I am assuming that the only thing between the solar panels and the battery is the diode, and that there isn’t any sort of current / voltage limiter on the board.  Can I assume this? Is the diode likely to handle me doubling the power through it? 2. My calculated peak solar power for the two looks to be about 250 to 300ma.  By following the 10% rule for charging and assuming that I’ll likely not get 100% rated solar power for long,  I’m assuming that I my D-cell should handle the trickle charge? C) Increase the power through the white LED’s.  This is my main question, and biggest uncertainty. 1. I am assuming that driving 100 lights off of one battery does not really get close to the maximum.  I pulled the shrink tube off of one of the LED’s and it appears a simple parallel connection.   I don’t see any resistors that are inline with the LED bulbs or directly before or after the LED string wires on the board. I’m assuming that I can add a resistor in series with the light string. Will the light output change much? How can I figure out what resistance to add without blowing my LED’s? Am I on the right track? With my very rudimentary (and possibly wrong) multimeter skills, I tried to find the following as well: Battery voltage – 1.16 v Voltage (measured as parallel with the light string) – 2.56 v Current (measured in series with the light string) – 13.1ma (this sounds low?) I’m slowly learning my way through this, and I want to put together an ‘ible together when I’m done.  Any help, corrections to my assumptions or suggestions you have are appreciated. Sorry for the long-winded message. Craig

Topic by harley1974   |  last reply


Cloning the famous ARA-2000 antenna for SDR use

Several years ago the company behind the original ARA-2000 antenna, Dressler Hochfrequenztechnik, closed.The ARA series of antennas, like many other products by this company never got a patent, instead it was trusted that no one would bother to replicate it.A bit like the Swiss Army knife, many tried to copy it, none really managed to match the original quality.There is quite a bit of hacking still going on for this antenna, most projects though seem to be abandoned at the time of writing this.I am currently trying to figure out how to create an entire clone that everyone who knows how to properly use a soldering iron can build.There is a lot to consider here...The active element is of quite unusual shape and needs to be wound around a cylinder of a pretty accurate diameter.My initial tests showed that for example aluminium foil with some unavoidable wrinkles already has a negative effect.And a change in diameter of just 2mm means the entire antenna only performs badly for the entire band.This part is thankfully already solved to my satisfaction using thin copper sheets and some stiff plastic sheet.Quite a pain though is the MMIC part - the amplifier that makes the antenna active.There is a ton of MMIC blobs available, either solo or as a ready to go amplifier.Downside is that without really knowing any characteristics of the original is comes down to guesswork.And as most of the cheap SDR dongles won't provide a BIAS TEE I will opt for an external power supply for the amp.I might provide the option for a inline use a bit later though.Why clone the ARA-2000 antenna?For starters you need to forget the mythical stories you might have heard about this antenna."Picks up even the weakest signals!", "Totally linear over the entire bandwidth" and so on...Without the amplifier the antenna is actually not even average in therms of reception performance.My initial tests with a network analyser showed that the anteanna actually is behaving really weird (without the amp!).Although this first bit needs further testing, it seems that most, if not all of the work in the 1.5-2GHz range is done by just the straight connecting strup going from the amp, or in my test case the coax, to the wrapped antenna part.For anything in the more interesting frequency bands it seems that the antenna is not using anything like a discone, whip or ground plane antenna.Instead the 3rd harmonics of a given frequency provide the max power output from the antenna but it arrives at the cable at the right frequency.Especially in the lower frequencies, below 200MHz there is also quite some phase shifting happening.As a passive antenna it seems to be almost impossible to find a frequency to transmit on without using some matching trickery first.But when it comes to size or looks, the ARA outperforms everything you can think of unless you want to constantly adjust the length of your whip antenna.And if you check what is available in real (user) data in terms of noise and signal quality than most other antenna types are far worse.The design provides a wide frequency range with very little noise, almost like a build in filter.Considering that mostly harmonic frequencies are used not that surprising.Getting hooked on SDR means you start little and then you want more and more.Unless you really need the low frequency HAM bands below 50MHz the ARA is a good choice that just makes sense.What is quite surprising in the original is the total lack of protection for strong signals.Sure, we might never need a lightning arrestor because all is enclosed in plastic and has little attraction lightning, but someone hittiing the transmit button close by....I will have to do some more checks to determine whether or not more protection is required.What is the problem with amplifier?For starters, no one really knows what was used in the original - they all just guess based on how well the real design matches some datasheet.Means whatever was used might as well be a custom made solution.I checked a few datasheets for MMIC amps but could not find any useful reference to the handling of things like negative gain, phase shift or a constantly changing impedance.Some however state that a 50 or 75Ohm signal is provided at the output.If I interpret that correctly than those MMIC's not only amplify but also do some matching.In most cases you won't need an amp that works outside what the antenna can provide.Problem is that I don't like regretting things later on ;)So IMHO it would be best to use a wideband MMIC covering all from about 1MHz to a few GHz.Additional filters can then cut off what is not required or where the antenna starts to fail.What is clear by the original design is that the cable shield acts as a ground and most likely also has a balancing function.It would make sense to add a ferrite trap close the the receiver to filter out what the cable might otherwise mess up.Can the frequency range be lowered to get even the low HAM bands?The answer is YES and NO.It is not a big problem to extend the cone shape and then hope to come much lower.Issue with this is the helical, long periodic design.As basically only the 3rd harmonics are used for all interesting frequencies any ARA type antenna going much lower would end to be really long.You can't just make it longer!One thing is to have a full and even number of turns.The original only had two, three turns is bad, four means the entire antenna is slightly longer than your average downpipe for your roof gutters....Other, seemingly logical alternative would be to stick to two turns and to increase the diameter.Apart from the size problem here we would also change the shape of the foil quite a bit and I have not done enough tests with that to provide a conclusion.Are there alternative design options?As it turns out copper pipe is available in 80mm diameters for the use in chimneys as well as downpipes.With a proper machine it would be pretty straight forward to remove what is not used as the active element.Milling a pipe or rod is these days a common thing in many good workshops.But on a hobby level and low budget....One of the best options for cheap test antennas of this design is to use tinting foil - the cheapest you can find ;)Just read the lable and make sure it does not use a metalised film.If it has no UV protection and no tinit at all it is best but hard to find.A little less stiff is the stuff to cover school books or cupboards.Vinyl is bad though!If you look for copper foil in the cheap online places you mostly find the suff used for shielding in rolls of 200x1000mm.Unless you have a really sharp knife or really suitable sissors this stuff is a pain to cut as the glue tends to stick very good to whatever you use to cut through.Don't ever try one of these blade type cutters for paper and pictures unless you put a slight oil film on all cutting surfaces first....In some hobby shops you can get copper foil without any glue in different thicknesses - this stuff is the prefered option.Not only cheaper than the China rolls with glue but you invest a bit more and get a thickness that does not wrinkle right away when working with it ;)Cheap, steel downpipe and cutters or nibblers?I though about and I tried - and I failed LOLUnless you use a pin type nibbler and custom made rig the result is quite bad - at least mine was.What works though is to use thin aluminium sheets, cut them and then bend them around a suitable template.But I ran out of old laminated sings to salvage and the duble sided ones I have left are too much work.What comes next?Well, I have a few rolls of copper sheets coming next month, the cheap glue covered type.This time however I will leave the plastic cover on and use tape to secure the foil to the pipe.A two-stage amp with external power supply is coming too so I can do some more tests in this area.For the time being I will opt for some 3D printed end caps but with a bit of luck can find something easier next time I have time to waste in the hardware store.Excluding cable and a cheap USB or 12V power supply, the current costs of building the anteanna are around $40US.About half of that if you don't cennectors and attach the coax directly.Another experiement I am working on is to use copper tape, 12mm wide, to create the antenna in a semi-fractal style.I am hoping this will provide a high enough gain so the antenna is usable without an amplifier.Right now the biggest issue is to find a really SDR suitable way to deal with strong signal close by.I will keep you update here when I start with the new antenna and upload some pics along the was of building it.

Topic by Downunder35m   |  last reply