LED CURCUIT

Hello,  I do not know very much about electronics in general but I would like to make a circuit that allows me to run a group of " LED "  lights, maybe ( 6 to 8  ) in PARALLEL.  I would also like to do the same for hand held " Lasers "  ( 3 to 4 ) in PARALLEL. To make it more complicated, I would like to be able to use the same power source to run both groups at the same time. I would like to be able to turn either group on or off independently while using the same power source. The power source will either be --2  D cell -- or -- 4 AA -- batteries. Normally each LED uses 3 hearing aid batteries. This is the same for each LASER pointer. I think each hearing aid battery is about 1.5 volts but Im not sure what the amperage is. I would like to do it as simple as possible. I hope I can get all of the parts at Radio Shack. I have no idea where to start, any help would be appreciated !

Topic by I Need To Know 8 years ago  |  last reply 8 years ago


help with shorting probem on my curcuit

This circuit does not work because of a problem with power shorting to ground at the motor. I think that is the only problem. The servo provides a 4.5v power source and the polarity can switch allowing the original 4.5v servo motor to run forward and reverse. I am making this to run a motor on 12v and the servo on 4.5v. R1 keeps the transistor saturated and the R2 is in there because I read it would help the transistor turn off completely. I made this circuit work (the right voltages went to the right places) in one direction but now it is more complex, I think I’m having a shorting problems. Can anyone help?

Topic by kendallickes 10 years ago  |  last reply 10 years ago


I need a simple curcuit ?

I need to turn on a 24vdc relay (apply gnd ) with a transistor. I have a 5v signal as the sourse from an industrial computer

Question by daveaprile 5 years ago  |  last reply 5 years ago


anyone know if this curcuit will work?

Basically I am building a robot and I have reworked some servos on a rc control to switch current from + to - and back to - and + depending on which way the joystick is. so at the top of the pic is my + - in that can switch to - + I need a curcuit that will run to different relays depending on the direction of current. Will the one I made work. I'm wondering if the power will feedback throught the other relay. by the way the black arrows are diodes Also does anyone know the difference between a reed relay and a regular relay. I looked it up but it doesent make much sense.

Topic by kendallickes 10 years ago  |  last reply 10 years ago


Boost curcuit amperage issue? Answered

I am planning to make a small boost converter similar to mintyboost. I am using a boost IC that will give me about 92% efficiency with the voltage i have. The output is 5v at 500ma, and the input voltage is 2.4v. Would the ic suck up more than 500ma per hour from the batterys?

Question by astroboy907 9 years ago  |  last reply 9 years ago


Things to make out of old PCBs

I have some old PCB scavenged from some electronics and a router that no longer worked. They are quite big. I may scavange some parts from them in the future but they are pretty much useless but they look cool. I was wondering what i could make out of them something decorative or even functional. 

Topic by mattdenney 5 years ago  |  last reply 5 years ago


IMPORTANT question about my curcuit

I have 6 of these and they are perfectly set up  http://www.radioshack.com/product/index.jsp?productId=2062569 and now i have this for a remote control http://www.ebay.com/itm/350584578972?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 and finally i have this battery to power it all http://www.radioshack.com/product/index.jsp?productId=3932591 can someone please tell me if this will work to be just a remote control led system  

Topic by dsl158 6 years ago  |  last reply 6 years ago


how do you make led's blink and chase?

I would like to use a small cr2032 battery with LED's How many Led's will a 2032 battery run? What about wiring several 2032 in series? and I would like to make them blink and chase ex 1 lights up 2 lights up ect I would like to make them run off a switch that controls steady on blink and chase any ideas would be greatly appreciated. Thanks Christy

Question by 9 years ago  |  last reply 7 years ago


Looking for a LED curcuit that will tell me when my AA batteries are charged using solar cells?

All the DIY solar chargers seem to use a feel test or a multi meter to test if batteries are charged. Is there a curcuit utilizing an LED like those on manufactured chargers, that will let me know when my batteries are charged, and possibly put them in float mode or turn the unit off?

Question by heyfeaver 9 years ago  |  last reply 9 years ago


Disposable camera hack? Answered

Hi, im building a capacitor bank for my coilgun, and I have 17 disposable camera capacitors in them. (wired in parallel (or whatever one means + is atached to +, and - is atached to -)) But for some reason wenever I start chrging it, after a little wile, it makes a huge spark across one of the capacitors. That probobly means its arcing right? but its only 300 volts (there wired in parelell so only the amperage goes up, not the volts). I then tryed to charge the caps to a point before they arced, wich took about 1 min (the battery is full) and my ammo only shot 3 inches! 17 capacitors, charging for 1 min, and it slid across the floor 3 inches! I have no idea what im doing wrong. Im using wire from a microwave motor (wich is realy small) for the coil, and its 5 layers thick, wrapped around a hollowed out pen. So, to sum it all up, here are the main problems: 1) the caps arc when charging 2) the ammo only goes 3 @#%!ing INCHES!!!!!! arg! Ps, i heard someware, that if you have enought amps, it will arc even with lower voltages. Maby thats whats happening? PLEASE HELP!!!!!! :(

Question by Stuffses 9 years ago  |  last reply 9 years ago


Modifying Altec Lancings "Life Jacket 2" Waterproof portable speaker.

So I got one of these portable speakers for work. Works great though it could be a touch louder. It lets you charge your phone while either using Bluetooth or direct aux input. Now there's only one problem/annoyance. Every time you power on/off the device and sync to Bluetooth, this voice confirmation plays this audio file that's much longer than it needs to be. "Powering on! Welcome to Altec Lansing" when Bluetooth kicks on "You are now paired! Enjoy!" when you turn off "Powering off!" Anyway, I was already planning on modding it by adding an amplifier to the Line In, since its much louder when a PC is connected vs a phone. I may also add more 18650's but with 15 hour battery life its not necessary. Unless I plan on turning it into a charging hub for all my co-workers phones or something. Anyway, I am here to try to get some help on disabling the voice, its only really a problem because on max volume the voice is WAYY too loud and usually startles people. Here's a review video that shows all the features. Amazingly I can't find a Youtube video of the Voice Confirmation. Here's the useless manual. Manual I Already emailed Altec Lansing to see if there's anyway to disable the voice. I have several images for you to see. I can grab more if necessary. Alternatively, would I be able to just replace the entire board with another one? Such as, an amplifier, USB charger, 18650 charger, and some hacked up Bluetooth headset (with no voice-confirmation) I ask because I rather like the case for its shock resistance capability, and the control buttons are removable so adding new controls and switches would be easy.

Topic by Crusty-Bobcat 3 years ago  |  last reply 2 months ago



how do I make a simple curcuit for a homemade robot?

I know there is a way to take a simple, cheap motor and a battery and some wires and make the motor work. However I have no idea how. Please direct me to an instructable with photos for this, I want to try a project.  gotta figure out how to make the circuit work first. Thanks

Question by pattyelaine72 8 years ago  |  last reply 8 years ago



Radio control question Answered

Would putting a 27 mhz frequency crystal  instead of the one shown, and a ajusting it to the right amplitude make a RC work  with this curcuit http://sci-toys.com/scitoys/scitoys/radio/am_transmitter.html?

Question by jbaker22 7 years ago  |  last reply 7 years ago


Old transistorized \ferriterod inverters 2ör4"burnt tubes were used. Here I tried with burnt cfls( w/o curcuit) no dia

How to use burnt cfls in transistorized inverter circuits which was using tubes.?

Question by sanghajeevi 9 years ago  |  last reply 9 years ago


Adding capacitors. Series or parallel? Answered

I was building a curcuit and had no 0.05uf capasitators so I decided to use five 0.01 capastators. Should I wire them in series or parallel? Also they are ceramic. Thanks for any help. David.

Question by David97 7 years ago  |  last reply 7 years ago


schematic for emergency lamp

Hi I have T4 Fluorescent Lights (8W 24v '1Feet length') and 6v 4Ah battery. I Would like to make an emergency lamp with these. Can anyone send me a curcuit diagram/schmatic.. Just manual switching on and off will also do. Thank  you  

Topic by nominds 9 years ago  |  last reply 9 years ago


How can I multiply/double (or just increase) voltage in a DV 5v curcuit ???

ok i have the following parts to ue for this: (all leftovers from former project..)  :) 1x mosfet IRF510 power transistor 5,6A 100V 9x 2N3904 amplifier transistors 40V 0,2 A .0.625 W ~16x 1uF capacitors 50V ~99x recifier diodes 1A 50V ~35x 2k resistors  0.25 W the idea is to charge a battery pack consisting of 4x 1,2-1,25V = 4,8-5V 3000mah AA nimh batteries using my 5v usb wall charger that has 1A output! i tried connecting the battery pack directly to + and - and 'i think' its starting to charge but after 1-2 hours at full rate (5v 1a) it should be at least 50% charged (3 hours would be full charge -> 5W x 3 = 15W), but if i connect them they last for about 2 -3 minutes and then empty again!! so after this im concerned that i might need at lest 6V-10V to achieve the desired effect !!  -> charge 15W NIMH batterpack with wall charger (nokia ac-60e.. 1-1,5A) i nless than 3 hours (as like a phone would need !!) therefore i need a cuirciut (ONLY DC) to double my 5V OUTPUT to 10V (yiou shouldnt apply more than twice the curent of a batter pack) or ideally 6-7 V but i dont know if thats possible without a swiching IC or more different resistors.. so just doubling would be nice at the moment!!  

Topic by sblocc10 1 year ago  |  last reply 1 year ago


Cordless drill battery packs.?

I have a ridgid impact. It cuts off when im assuming the curuit board inside the battery senses to much load. ide like to fix this problem with an override on the circuit board or just bypass the board itself but i need to know, does the battery charger know when the battery is charged or does it need feedback from this curcuit board in the battery? thanks

Question by thomas7.3psd 7 years ago  |  last reply 7 years ago


There is lot of ic's that can produce ultrasonic Freq. plus. Is it possible to catch the bounce back and trigger relay?

Is it possible to triggering  a relay by freq. shift or tone? Some of those ant-barking curcuits that use 555's is it possible that they could they be modified for proximity detector use? Could  transmitter  catch the signal or tone on the return  the echo bounce and trigger the relay. Also can some of those Max Bot's run directly to a relay and work? 

Question by 9 years ago  |  last reply 3 years ago


Coleman car Jumpstarter charger wallmart voltage ? Answered

I have the circuit out of one of these , I see that it can charge a 12v 7.5 amp sla, what is the voltage of ne of these that wallmart connects to the charging circuit model PMJ8160 Coleman thanks, if no reply I will try a 12v 500 ma wallmart as this curcuit has a lm324n which boosts voltage to i think 13.5 etc. thanks all.

Question by celalboz 5 years ago  |  last reply 1 year ago


A 3.2-3.6 green forward voltage LED , uses 2 ma. to operate? What amperage can it safely handle?

I would like to use one as a charge indicator for a 2500ma. rechargeable AA battery connected to a 2v., 600ma. (full sun) solar panel.2v. solar + 1.2v charged AA battery = 3.2+ v. and should turn the LED on, but can it handle the amps. or does it need a resister in the curcuit to protect it?

Question by heyfeaver 9 years ago  |  last reply 9 years ago


Coil gun trouble

I have been trying to construct a simple flash curcuit coil gun as i have seen on the internet. I thought i had everything hooked up right but when i go to fire i get a nice spark but no acceleration what so ever. Can anyone tell me the proper materials to use and a step-by-step in coil construction and how to hook up the leads properly TO MAKE IT WORK! any incite is greatly appreciated

Question by Steve smart 7 years ago  |  last reply 7 years ago


Wireless LED project

I'm working on a project where i need a circuit board with about 15 LED's. But i need to have a switch turn them from a very shot distance, about 3 to 5ft. so i CAN NOT have any wires, and dont want wires. So i already assume a power supply should be mounted on the circuit board, and at the switch. But i don't know what else i need. Is there a tutorial i can find ? Could i get some help ?

Question by mrcs 10 years ago  |  last reply 3 years ago


how to work this ac motor speed control circuit using 2AC input? Answered

Please let mo konw how to working this curcuit. I think Left one both ac input. So, SCR always turn on and off. than ac motor contineuly rotate isn' it?... But, this pic shows downscaling elevator moving circuit. I want some explain. plz someone help me.. left 15V both AC, right R1.T1 are 220V AC

Question by mr.kdy 4 years ago  |  last reply 4 years ago


ATX Variable power supply circuit problems? Answered

I finished putting together the variable power curcuit board I had asked about earlier. I am getting 0-18volts with no load applied just my meter. When I try to connect a small dc motor or anything to it , my voltage goes to 0. I used a 5k linear taper potentiometer and didn't notice untill after assembling that it is only rated for .5 watts. Could this be the problem? I also used a salvaged ceramic cap, and a salvaged 1uf cap, but dont know how to test them with a regular fluke multimeter. Could somebody please help! I'm a newbee, so I appologize for my electronics ignorance, but we all got to start somewhere.

Question by pollock9131 8 years ago  |  last reply 8 years ago


build a 3d printer with a standard stepper motor controller? Answered

Hey Im thinking about building a 3d printer, so I'm looking at the (endless) possibilities out there. Can I build one with a standard (4 or 5 axis) stepper motor controller (like the ones on ebay)?? instead of using an arduino (I saw on the internet that that's what they use on RepRap) (and since I'm building a 3d printer/ CNC I think it would be more convenient for me to use stepper motor controllers for "both" the machines, and besides that it appears to be simpler since I know nothing about arduino :( ) I was thinking I maybe could use a controller with 4 or 5 stepper motor outputs and then use 1,2 and 3 for the axis and then use the other one to "tell" the machine how much material it should "spit out" any advice?? or any other ideas for a SIMPLE 3d printing curcuit?? 

Question by lordl9999 6 years ago  |  last reply 6 years ago


Rc car modding help?

My dad had (broken) a rc car from a old friend that was sitting in the garage. He said that I could have it. It is a Nikko Super Dictator. When we were trying to fix it the curcuit board went poof and clouds of smoke came out of it, I don't want to fix the board but was thinking about buying a cheap RC kit and using arduino to decode and to control it. Another way I thought of controlinng it was to get an rc kit and use a speed controler. The servo in it has 6 wires and has no markings on it to tell me what it is. If anyone has done this project before please send me a link to an instructable. Also Please tell me the easyst way to control it and if I could just use a prebuilt rc kit with a speed controler, the type of servo and the motor. IF ANYONE HAS ONE THEY WOULD LIKE TO SELL THAT WOULD BE GREAT TOO, JUST SEND ME A MESSAGE. Any help, tips and/or links would be appresated. PS: Do a google search to find out stats. thanks, David.

Question by David97 7 years ago  |  last reply 7 years ago


Will this RGB LED manual color changer circuit work? Answered

I am working on making a lighted banjo head, and thought to use an RGB LED strip (http://www.sparkfun.com/products/10259) so i can change the colors. I am new to electronics, and have no real programming experience. As such I designed this curcuit to work with basic parts i can find easily at hobby stores. I reasoned that if i increased the resistance of the circuit with a potentiometer, I could dim the LED's. The led strip takes 0.02 amps at 12 volts and is common anode (it has built in resistors for each LED). I cant find low resistance potentiometers so i thought to put 5k ohm pot in parallel with 680 ohm resistor to get the required  resistance of 600 ohms to shut off the LED.   I have looked around the internet and haven't seen anyone use this method, so im wondering if it will work. Any help is appreciated as i hope to make an instructable of this project! Thanks, Pie Here is a circuit diagram:

Question by pie R []ed 7 years ago  |  last reply 7 years ago


Disposable Camera Hack?

Hi, im building a capacitor bank for my coilgun, and I have 17 disposable camera capacitors in them. (wired in parallel (or whatever one means + is atached to +, and - is atached to -)) But for some reason wenever I start chrging it, after a little wile, it makes a huge spark across one  of the capacitors. That probobly means its arcing right? but its only 300 volts (there wired in parelell so only the amperage goes up, not the volts).  I then tryed to charge the caps to a point before they arced, wich took about 1 min (the battery is full) and my ammo only shot 3 inches! 17 capacitors, charging for 1 min, and it slid across the floor 3 inches! I have no idea what im doing wrong. Im using wire from a microwave motor  (wich is realy small) for the coil, and its 5 layers thick, wrapped around a hollowed out pen. So, to sum it all up, here are the main problems: 1) the caps arc when charging 2) the ammo only goes 3 @#%!ing INCHES!!!!!! arg! Ps, i heard someware, that if you have enought amps, it will arc even with lower voltages. Maby thats whats happening?

Topic by Stuffses 9 years ago  |  last reply 9 years ago


FREE Schematic publisher(also includeds breadboard and PCB view)IN ALPHA

I did a search and didn't see it on this site anywhere, but I see a huge need for a number of the members here to be able to draw schematics and even simulate a breadboard or PCB. This software is free(but it is still in ALPHA testing). I have no affiliation with this site so I can only answer questions about usability from my opinion. For what a lot of people need on this site to help make "instructables"  that have electronic curcuits in them I think this is perfect. Especially if you can't afford high dollar software, plus if you're not an electronic engineer this software will teach you proper terminalogy and proper drawing designations as well. From what I know, all parts on the program are editable. So if you need a green 3.6v LED you can edit the one that comes default on the program and save it in your tool kit and use it for another project later. Hopefully everybody sees this. If the Mods know of a place to put this where it may be more accesible and visible to everybody here, please move it. Here's the link to find the software. They have it for Windows, Mac OSX, Linux 64 and 32 bit http://fritzing.org/download/ Enjoy PS, don't forget this software is in Alpha, so contact the devs and tell them if you have problems or you'd like to see changes

Topic by navyredman 9 years ago


Calculate Resistor for Heating Wire

Hi there, My Goal is to use a piece of heating wire from an old hair dryer  (1.6 Ohms resistance for the length i want to use.) and heat it red-orange using my old USB power bank. 5V output from an 3.8V lithium ion battery i dont want to mess with the circuitry inside. Problem: The USB Power Bank has short curcuit prevention built in, so when i connect the heating wire the power bank stops supplying electricity. I found a 7.5 ohms resistor and connected it aswell, the wire became a little warm, the resistor incredibly hot but most importantly the power bank continued to supply power - success. I would like to know what resistor i should use to get the wire red-orange hot but at the same time keep the power bank safe and not overwhelm it - i think that would mean not drawing too much current? I also cant check how much current is flowing because my multimeter is too cheap and only goes up to 200ma, which the power bank exceeds. So how would i go about this? What resistor should i use for what wattage should it be rated. And since im a total newb id like to hear your train of thought as to why and how. Thank you so much.

Topic by emiliori 2 years ago  |  last reply 2 years ago


Why wont my LED circuit work?

First and foremost, thanks for any help, time, effort, info, etc on this website provided by anyone to anyone. I actually have three small questions.... I'm trying to make a simple LED series circuit using 4 red leds rated at 1.85v@20mA. Im using a 9v to power it with a 100r ohm resistor. Doing the math on the resistor calc, I believe I should be using 85 ohm resistor, so for good measure I went with a 100 ohm. First question... - Is 100r ohm resistor the right type? I'm only asking cause after this didnt work, I started wondering what that "r" in the "100r ohm" package ment Second.. - For a series curcuit of this typ...do I need a resistor on each led or just on the positive lead from the 9v? Third... I tried hooking everything up by just laying the contacts across one anouther and nothing happened. Basically from the 9v+ terminal to the 100r ohm resistor to the positive (longer) lead from the 1st LED. Then the expected 1st LED neg to 2nd LED positive, etc, till there was 4 like this. Then the neg lead fronm the last LED went to the neg terminal of the 9v. Nothing...zip So from there I tried just one LED going to a AAA (1.5v) with the same resistor and the same lack of results. Tried different LEDs and batteries with no luck. Any ideas? Seems too simple to be messed up, but it's obvious that I'm not doing something right. Sorry for the ease of this prob. I know that this has been covered fairly extensively on the this site and the net, but I don't understand what I'm not doing right. Any help would be appreciated. thank you

Question by rangeside 10 years ago  |  last reply 10 years ago