The forums are retiring and are now closed for new topics and comments. The existing content will remain online and accessible through 2020 to provide everyone the opportunity to save any relevant information. In the spring of 2021, these Community forums will be taken offline.

Search for Circuit design in Topics


Circuit design

Hi, I’m hoping someone could help me. I’m looking to design a circuit for a college project that controls a 240v light. The circuit and light will be controlled by a switch however when the switch is first turned on the light needs to remain off (no power supplied) regardless of the amount of time the switch is on. If however the switch was turned on off and on again then the light needs to come on. Any ideas of a circuit and components required to produce something like this? Your help is greatly appreciated.

Topic by Worby10    |  last reply


LM35 circuit design

Hi, any advice on putting an LM35 into a circuit to control a small (120w max) DC immersion heater element so that it maintains water temperature around 38C ? Thanks

Topic by RionZion    |  last reply


Circuit Design Edumacation

Can anyone direct me to free internet resources that will help me with circuit design? I can usually figure out what type of parts are needed for a given circuit, but am often completely stymied by what specific parts to select - what resistor value, which transistor, what voltage and uF cap? What's available? Thanks!

Topic by homba    |  last reply


Circuit Design Question

Ok, I have a power source that outputs about .5 volts sometimes, but at other times as much as 12 volts. I want the power to illuminate an LED in both cases, without burning it out. I think I need a capacitor for this but I'm not entirely sure? Can anyone tell or lead me to a tutorial or circuit diagram that shows how to do this? Thanks!

Topic by Joe426    |  last reply


LED Circuit Design?

I'm a Mechanical working in the LED field. I'm trying to design a LED circuit with the little knowledge I have. Here is my circuit in a nutshell: 3.2 Vf typ - 3.6 Vf MAX -.150 mA 24 volt CV PS supplying 3.3 A 7 series in parallel with 22 chains I calculated using typical Vf as the following: 24/3.2 = 7.5 devices so I rounded down to 7 devices in a series chain. 7*3.2 = 22.4 volts required 24 supplied - 22.4 volts = 1.6 volts to dissipate. Resistance = 1.6/.150A = 10.67 ohms Wattage across resistor = 1.6*.150 = .24 W So I found a SM resitor 10.7 Ohms at .25 W. I have a concern with Vf variance. Would this circuit not work if I get Vf's higher than 3.2 Vf? So if I change my circuit to 6 devices per series chain I need 19.2 volts and need to dissipate 4.8 volts. This just seems like a waste.I still do not understand Vf variance. If I design for 6 and dissipate 4.8 volts with a resistor - won't the series chain be starved if Vf goes higher? So how do you accommodate this variance? I just have worries about this design - regardless if I design for 6 or 7. I know some about LEDs but I do not know what happens when I get Vf variance. Does the resistor go at the end of the series circuit? If this is the case then I understand how variance in the circuit would be able to use available voltage - and then the resistor is at the end to disipate what is left over. I've heard concerns that I'm not allowing for more head room #i.e. doubling the resistor value and wattage requirements). If I double the voltage dropped don't I take this away from the LED circuit possibly starving it? I have always assumed the resistor goes at the beginning of the circuit - regulating the current/voltage prior to it entering the LED series circuit.?

Question by oharag    |  last reply


Circuit Design Help

Trying to build a simple circuit to power a small pump while the sun is out. Here are the specifics: Solar Panel (60 cell mono panel) Open circuit voltage 36.4V DC, Short circuit current 7.96A. Pump 12 V DC, 9A max Using E=IR ,  R=E/I, (36.4-12)/7.96 =  3 ohms Power = V(sq)/R = 24.4/3 =198 watts  I purchased a resistor that meets these requirements and hooked everything in series. (Solar panel lead to resistor, resistor to pump, and pump to other solar panel lead. The pump does not turn on when the panel is in the sunlight. I measure the voltage coming out of the panel and it is within specification. I also tested the pump by hooking it up to a car battery and it works fine. Any ideas what I am doing wrong? thanks!

Topic by OMGIMDUMB    |  last reply


circuit building and designing?

Hello i am new to electronics i want to know how to design/design a schematics a specific  circuit i means where to place resistor ,cap,and other electronics  i have perfect idea about most of basic electronic component but can any one suggest a method to build own circuit or scematics?

Question by mihir.sahu.355    |  last reply


Genetic Circuit Design

Hackaday recently posted an article about genetic programming which was pretty cool (although technically it used a stochastic hill climbing algorithm....but who's counting?)The really cool thing was posted by acedio in the comments: genetic circuit designWhat these researchers have done is implemented genetic circuit design on an FPGA to create a circuit to light a light when someone says "go" into a microphone and turn it off when someone says "stop". Which is not really groundbreaking...but the way the genetic algorithm created the circuit is pretty amazing, it used what normal designers would consider unwanted characteristics of the circuit such as stray capacitance and inductance between components to "create" unavailable components out of logic gates, and because of this the researchers have no idea how it works!Computers can now design circuits in ways that would be damned near impossible for humans to do, how cool is that??!Deep thought here we come!

Topic by }{itch    |  last reply


Designing the circuit for robot

I am trying to design a floor cleaning robot that is also a obstacle avoiding robot. I want to use two tt dc motors for the wheels, a servo motor to control de ultrasonic sensor and a dc motor to rotate the sponge. Currently I have a Lafvin super starter kit that brings a L239D motor driver that will move the wheels but I am having trouble visualizing how to connect the DC motor and the servo motor. Can someone help with this circuit?

Question by prezgab    |  last reply


Designing a simple circuit

Ok guys.. so i think this might actually be my first post ever here! Down to business... without giving away my design before I have a chance to build it and such, ill be a little general, and using a different scenario than my actual plan.. i hope you guys are ok with this. It will be an instructable after i get going, i promise you that. So I was hired (i'm running a small business doing custom LED work) to make a project for a league I play in. The premise is simple. We need a way to keep everyone informed as to who's turn it is for the game. As it stands, there is simply a matter of the players staring at you, or mentioning, "let's go!"  which is quite embarrassing. So the design is relatively simple. I have one button (LED center) and one switch per person.   The button signals that you've completed your turn, the switch (when moved to the OFF position [preferably OPEN] )indicates to the microcontroller, or whatever I design to replicate the microcontroller, to skip your LED button if your turn should come around again, and go to the next person in turn. Using the most simplistic way, how would i go about this? I may make a picture of my idea, but its really late and im headed to bed lol, so that will be done tomorrow.  I'll give another example, say there are 4 people at a table, and player 1 and 2 complete their turns. player 3 chooses not to play for the remainder of the session. Player 3 turns their switch off, and play passes to player 4. Player 1 goes, Player 2 quits like player 3 (switch goes to off position), and then it goes to player 4.  Pay attention to the bold in the previous paragraph. How would this be accomplished? Remember, an LED button is being pressed to signal end-of-turn. Any ideas or nudges in the right direction would be perfect. I'm not looking for a handout, so just suggest, NICELY PLEASE or link to related materials. I like learning, so handouts will not benefit me, unless you tell me WHY, so that i can remember it for next time, if there is a next time lol. I appreciate this you guys and gals. I take a lot of knowledge away from every instructable I follow along with.  --Mikel

Topic by mikelspencr    |  last reply


Voltage regulator circuit design

Hi, I'm trying to make a DC - DC voltage converter. The real purpose is to power an old USB hub in a car. This is because so many of my electronics these days use USB to power them and rather than have a nasty mess of car power adapters I want to use a single 12V supply for the hub and then plug all of my goodies into it. Now for the meat of the question..... What is the best circuit design for using a voltage regulator. I have looked at some stuff in data-sheets and it just seems way too simple. The part I'm looking at using is a National Semiconductor LM1085-5.0. Input voltage 6.5 - 20V output 5V max of 3A

Topic by Sailing_Nut    |  last reply


Help with circuit design! Univeristy design project

I'm a University design student creating a new safety goggle that causes the tool you are using to cut out unless you are wearing your safety goggles and I need help designing a circuit that could demonstrate the way in which it could work as I have very little experience with circuits myself.For the product I am envisaging: 1- the tool is be plugged into a box, which in turn plugs into a wall socket. 2- the box connects to your safety goggles via Bluetooth 3- when wearing the safety goggles, pressure sensors behind your ears help identify that the goggles are being worn rather than being left on the side or on the ground 4- the goggles communicate that the pressure sensors are activated to the box you plugged your tool into and it allows the tool to work 5- if you take the goggles off, then the goggles tell the box that the pressure sensors are no longer activated and the box breaks the circuit to prevent the tool plugged into it from working.Any ideas on how I could build a circuit to demonstrate this would be greatly appreciated. Thank you

Topic by FreddoFlakes  


Help me design the Circuit,

Hello everyone;I want to make power backup for my internet router which runs on, 9v and 0.6Ah or 600mAh, I bought the 9v battery but it could not provide enough current to the router to work properly, so now i have two 6v batteries which provides 4Ah current each and i want to use them for power backup, now i,m stuck at the point that how i'm going to make this voltage lower i.e 12V to 9V, however, I figured out how I can limit the current to 0.6Ah or 600mAh, i,m using 12v charger to charge these batteries while connected in series and will use it with router as well, can any one help me out the how can i decrease the voltage to 9V and use it power my router.i'll be grateful

Topic by TamurT    |  last reply


how to design circuit for bluetooth?

I have LVDT probs . i want to convert that signal in to digital signal ,and than that signal send with help of bluetooth.

Question by vijaysinha  


Circuit-design Peltier Element

Hi. I need a little help from experienced people. I want to control a Peltier element with a microcontroller, with PWM. May? The peltier element has the following parameters: Imax=8.5 A, Vmax=15.4V.Ok... I have a 12 volt source,17A for example. How can i design the circuit so that i can control the peltier element?I use TEC-40-33-127. A link to the peltier element data sheet is:https://eu.mouser.com/datasheet/2/433/Wakefield_Ve...

Question by uicElla    |  last reply


need help on circuit design

Okay, I really need help on this. I want to begin a plasma speaker project, but I require help designing the circuit. I can build stuff fine, and simple high-voltage things, but complicated circuits are simply beyond my ability to design. what I am planning on doing is having a standard audio plug (l/r) feeding one circuit-probably needs to be amplified, then split into two channels, then I intend to have each channel control the driving circuit for its own neon sign transformers, as thanks to a neighbor, I will have a couple. I just need help planning out the circuit-I see how people manage plasma speakers with flybacks, but I have no idea how to make a two channel audio amplifier that splits to drive two separate control circuits that control the 110v supply that each NST takes. So, please, I beg of you, help me. and thanks in advance.

Topic by Nyanman  


electronics circuit designing question? Answered

So i am pretty good in electronics, im curently modifing a circuit and just found the value of the resistors with the ohms law. i have to lower from 12volts dc to 3.5 volts dc to a 300mA consuming high powered led with the cathode to the ground. if my calculations are right i would need to use a 30 ohm 3w resistor, should i take a 4w so the heat is not too intense? the led is not going to be light up always, its going to oscillate on music(color organ). are my calculation right?

Question by pbergeronronronron    |  last reply


CAD for Circuit Boards

What software do you use for designing circuit boards? Do you like it? I've been using Eagle, but have been entertaining the idea of switching it up.

Topic by randofo    |  last reply


Can anyone design me a circuit? Answered

Hey Guys, I'm back asking questions (yay). I was wondering if anyone could design me a circuit for 6 Blue Leds in parrelel running from a 9v battery with a 555 ic to blink them. Thanks in advance. -Prickly Potato

Question by SA-DIY    |  last reply


Circuit Design Questions - Voltage Drop Answered

Hi there, I'm working on a circuit which will include a 3v, .7Amp motor and three 20mA LED chips, with a maximum forward voltage of 3.8v. The whole circuit is intended to run off a 6v battery.In calculating resistance for voltage drop, I've figured out that resistance for the motor is 2.1 Ohms and then (by Ohm's Law Resistance = Voltage / Current) the resistance of each LED chip is 190 Ohms. Is this correct? It seems astronomically high.?

Question by Zahv    |  last reply


Help with flashing LED circuit design.

Hello, I was wondering if some could help me with a circuit design. Designing is my weak point, so apologies in advance if it is a simple question. Basically, there will be 9 LED's in total, 3 in each row. It will be powered by a 9v battery. The LED's are 2.2v 50mA. So I want the 3 LED's in Row 1 to illuminate. Then Row 1, de-luminate fully, then Row 2 to illuminate straight after. Then Row 2, de-luminate fully, then Row 3 to illuminate straight after. Then start over again, so it's basically a sequence of 1,2,3,1,2,3,1,2,3 etc. From what I understand a 555timer is required?  I'm looking to do this as cheap as possible Any help or guidance would be appreciated. Thanks!

Question by leevon316    |  last reply


Need a schematic design for a simple circuit.

I was wondering if anyone here could help me design a particular circuit. The "device" would need a single button. When said button is pressed a buzzing sound would occur ( kinda like in game shows, you know that wrong answer sound?) then wait for five minutes and automatically buzz again by its self. Press once (BUZZ) wait 5 minutes buzzes again without the need to press again. I am perfectly capable of reading schematics and building prototype circuits. I just have no "nack" for design as of yet. Any help on this issue would be greatly appreciated. Thank you for reading my post. PS: I am a little rusty on some of the symbols, therefore a legend would be great.

Topic by ClaynEva    |  last reply


Help wanted in designing a switching circuit.

I have 3 inkbird controllers monitoring 3 beer fermenters. When any of the fermenters require chilling the Inkbird switches 230v to a pump. Problem is that there is a combination of any one on at a time or all three at once or none on. I can’t connect all 3 outputs together to drive the pump as the inkbirds will get damaged. Can anybody draw me a circuit whereby if any combination of of inkbirds switch 230v only one output is switched to the pump. Have attached a diagram showing all outputs connected together but have been told that mains connected across the Inkbird output will probably damage it.

Topic by CBBC    |  last reply


Electronic Circuit Design Help Needed?

I have an HP WebOS TouchPad and the Power adapter has died. I do not want to buy the same changer since it's the 3rd one that has stopped working. Would anyone design the power adapter electronic circuit for me? Also note that if I try any other changer that might have a lower amperage it will not change. AKA I get a screen that says, "use the correct changer outside the OS" Any help would be greatly appreciated. Power Adapter Wall AC to USB power adapter, which has input specifications of 100–240 Volt 50–60 Hz 0.4 Amp AC, and output specifications of 5.3 Volt 2.0 Amp DC. It is cylindrical roughly the size of a "D" battery with a foldable 2-prong AC connector and a Standard-A USB socket. Battery The TouchPad uses a rechargeable 6000 or 6300 mAh Lithium-ion polymer battery rated at 3,7 V (total 22,2 Wh). More info at http://en.wikipedia.org/wiki/HP_TouchPad

Question by nfarrow    |  last reply


Switching Circuit

Hi, I want to build a Auto-Switching circuit. I would appreciate if you could help me on circuit. Sorry for my ignorance in circuit design. There are two power sources A and B. The A is 12v and B is 3v.I would be utilizing the power from A only when B is turned On. So an auto switching circuit is required in this scenario. The circuit should sense if B is On, if so it should let A On.

Topic by arunsun    |  last reply


Circuit help

Been decades since I did any circuit design and I have a fairly simple need someone will certainly have a simple answer for.I need to run a simple pulse output from a 5 minute timer into a circuit that will have 4 outputs. Each pulse in will cause the next output in line to go HI, with the others all LOW. 5 minutes later, the HI will move to the next Output, with all the others again at LOW. Once the 4th and last output has gone HI, it will wrap around to the first output again, and so on. Sound a bit like a Ring Counter, but there is no CLOCK pulse here. Just a short pulse every 5 minutes or so to the input. Any help would be appreciated. This isn't rocket science, so simple and cheap would be a plus.Thanks.

Question by gjforeman    |  last reply


Volume limiter circuit?

I need help designing a circuit (off of another circuit) that will limit the output voltage to X. I need X to be adjustable from between 0-700 mV. However, I need it so as the input voltage goes up, the output voltage will stay at what it was set to. Without clipping. Any advice? Thanks!

Question by heyzuphowsitgoin    |  last reply


Power Sine Wave Circuit

Hi I am trying to build an economical circuit to power an AC electromagnet. The energy source has to be a battery, preferably less than 24v. The power draw of the electromagnet will be about 500W (the application requires a high-power alternating magnetic flux). I'm thinking of making a sine-wave generator and a simple transistor amplifier with high power transistors. Can anyone suggest circuits for this? My knowledge of electronics is not that great, but I'm quite enthusiastic about this and I believe I can give it a try. Any help will be appreciated. Thanks R

Question by Richy33    |  last reply


Need help designing a counter circuit. (I don't have a lot of experience designing circuits)

I am currently designing a counter circuit, however, i keep running into issues and a point in the right direction would be greatly appreciated. Components I want to include: - a 7-segment display and 4026 - a PICAXE and/or a 555 IC (the PICAXE would be used to turn the device off without resetting the 7-segment display) - an LED to show that the device is on - three switches: one to reset, one to turn off/on the device and one to add to the count - possibly a piezo buzzer to read the count on the 7-segment display (?)I have attempted to make this circuit (it is attached) but did not get very far. Again, any advice would help, thanks.

Topic by Spencer001    |  last reply


EMERGENCY LIGHT circuit

>i want a design of an EMERGENCY LIGHT circuit pcb> >i want it to run two 61 cm 20W florescent tube lamps> >the circuit should have a key to turn on or of and a key to operate one or two lamps> >u may use one key as u like , operation time on battery is 3 hours as minimum .> >i may buy the design after testing it .

Topic by spyman114    |  last reply


Need help with simple counter circuit design Answered

I am a newbie interested in building a circuit that can count the number of times a voltage level exceeds 2 volts.  Long story but I have an EMG device that will output 2 volts once a threshold is exceeded.  There is no way to automatically capture the number of times this happens.  Can anyone point me to a project kit that I could purchase or to a circuit with a component list that I could build?  I am fairly new so hopefully this circuit would not be too complex.  While not critical if it is also possible to capture the average duration the level stayed above 2 volts that would be great.  Understanding that this may complicate things beyond my ability the simple counter without duration would suffice.  Thanks.?

Question by fsudal    |  last reply


XKCD tries its hand at circuit design

The comic is at http://xkcd.com/730/. Who wants to build it first?

Topic by yoyology    |  last reply


What is the purpose of the charger circuits in the coilgun design? Answered

I am a freshman in college interested in constructing a coilgun. I do not yet know enough about electronics to understand the purpose of the charger circuits I see in the designs of most coilguns. I am hoping that someone can enlighten me.

Question by wft4    |  last reply


know of a good free circuit designing software? Answered

Hi everyone, I looking for a free electronics circuits design software that I can use in the classroom with high school kids. I had a play with circuitlab  which is pretty much perfect for what I need, just started showing the kids and, now it wants payment to continue. Had a look at 123D circuits again the video looks great but it doesnt seem to work anymore. Also tinker cad circuit doesn't want to play either. Fritzing and eagal cam is a bit hard for the kids to learn as they only have the class for a few weeks. It just has to be easy to use and be either online or compatable with mac computers. Thanks

Question by liquidhandwash    |  last reply


Circuit Design Help: LED Circuit that can be powered if positive and negative are reversed? Answered

Hi there, I am looking to design a circuit with: • Has 10 LEDs               o 5 LEDs in Series, with two of these sets connected in parallel. • I want the capability of the LED array to illuminate if one end of the PCB is powered by the positive and the other end is in contact with the negative.  And vice-versa, meaning the first end is now touching negative with the other end in contact with positive.                o I was told that I can use diodes, but I’m not sure by what configuration. I've attached something I've found online.  Will this work?  if so, can you provide an explanation of how it works?

Question by ThompsonGenie    |  last reply


Need advice and help for capacitor circuit design

Hi all Instructables friends,       I have been viewing instructables for quite some time and I like it very much, thanks to all the contributor here, I really learn a lot. This is my first post here, and I only have basic electronic ideas, never soldier or build any circuit, so please be patient if I made any stupid things :) I have an idea in mind, not sure whether it is possible to implement or not, so I need electronic experts here to give their advice. I have a very small palm size solar panel. need to build a circuit that can do the following : 1) The solar panel need to charge a small capacitor with a small capacitance, let say capacitor A 2) Then when this capacitor A is fully charge, it will charge capacitor B, which has higher capacitance. 3) The process of charging the capacitors with incrementally larger capacitance capacitor can continue to go on and on until some  level that I can make meaningful usage out of it, for example, run a corei5 laptop. (most likely I will use super capacitor at the last) My questions: 1) Is the above idea possible/feasible ? 2) If it is possible, will the capacitor lost energy very fast after some time? 3) I know people may suggest me to use battery, but I prefer capacitor or battery because battery life is very short compared to battery and it's not eco friendly either. 4) Any other concerns/warnings/advices are greatly welcome. Thanks :D

Topic by myuser001    |  last reply


led charging circuit

I dont have much experience designing circuits but i can soldier. I need to design a circuit that can charge 2 aa rechargable batteries and power 2 leds. Each rated at 25ma and 2.0~2.2. I want the circuit to be charged by usb and use a 3 way switch. Off, on (both leds) and charge. The usb will be plugged into a mains usb charger, not a pc port. I think i have included all important details. So please help me by explaining what i need to do and possibly schematics.

Topic by o0SLOVAKIA0o    |  last reply


Printed circuit bards

I was wondering if I can print my circuit design onto acetate and use it to expose my circuit board. Would that work? If not what could I do instead of of ording them for rediculous prices online?

Topic by pattyshaw    |  last reply


unidirectional audio speaker. Design discussion

I was thinking of designing a unidirectional speaker driver circuit. As far as I know ,I need to drive the speakers with audio signal with ultrasound carrier wave... I thought of making a circuit that generates 20/16 Mhz (1.25mhz) square wave? using 4060 ic and 20 mhz crystal and using optocouplers to torn on and off the speakers at same frequency. do you think it is going to work?

Topic by Suraj Grewal  


Circuit for power bank? Answered

Hello, Need a circuit design for the following requirement. Checked online available circuit designs but not sure if they meet all needs.  Looking for circuit design as per following details. 1. It will have one or two, 3.7 volts 2600 mah 18650 lithium batteries 2. Batteries will be charged using smart phone mobile charger or solar panel 10 to 20 volts and around 500 mah to 1 ah input 3. Will have mini usb connection for the same on pcb 4. Circuit should have battery level indication. While being charged, when they are fully charged LED should turn on indicating battery full. Also there should be one LED to show that the charging is in progress. When the battery charge drops below specific level another LED should turn on. 5. If we use 2 batteries then they will be connected parallel 6. Output voltage of the batteries should be 5 volts (so step up is required) and current should be appropriate for mobile charging 7. There should be provision for 2 USB connections. Load can be mobile charging / USB mini fan / USB mini keyboard LED (could be 2 at a time) 8. Circuit should be safe enough so no damage is caused to batteries / load etc.

Question by rahuldj    |  last reply



Would This Circuit Work?

A while back I designed this circuit, and to my knowledge it should work, but I just want to get a second opinion. It is a game in which there is a circle comprised of 12 LED's and the goal is for the user, to press a button, and stop clock so that the green LED in the circle is lit. There is another switch in the circuit so that the user can reset the game at any time. I'm sorry that the picture is very faded and a bit cluttered. Any help is appreciated, thanks!

Topic by FrozenStar    |  last reply


how do i wire a transformer to a circuit?

I would like to know how to wire a transformer into a circuit. Now when i say that i do NOT mean how do i wire a transformer as in build it, but wire as in connect it.take a look at this can link get any smaller? of course! that says of course!now i know that is a center tap transformer being used but i would also like to know how to wire a 4,5,6 pin transformer that gives a constant stream of electricity. and i would also like to know how to wire a flyback transformer

Question by miiwii3    |  last reply


Camera Flash Circuit

I know that it's pretty easy to cannibalize a camera flash to do some pretty simple things...but i find it difficult (probably by design) to solder things to these prebuilt boards (especially the "charge button"...that things not built for soldering)...i was wondering if someone could work up a circuit schematic with part numbers (or at least part identification) for a flash circuit like those in a disposable camera...so that someone could build it from scratch in whatever form factor they choose.

Topic by crapflinger    |  last reply


How this circuit works!!? Answered

I got a circuit board from an emergency light when i saw it's circuit it's not common there is a ceramic capacitor and a 330 ohms resistor in its and it give 5.0 volts at the end i don''t know how it's designed but it's giving 5.0 volts at the other end with  no transformers ! then i configured the circuit myself as shown in the given diagram but it's giving 180 volts dc instead of 5 volts so my question is  : is there anybody who can tell me whats missing in this circuit so its can also give 5volts output?

Question by ubdussamad    |  last reply


servo drive circuit

Does anyone know how to make the circuit like the ones inside srevo motors? I am designing a sumo bot with radio control. I need to use contenuously rotating motors with lots of power to drive the robot. I do know how to modify my servos so they contenuously rotate, but I don't think they will have enough power to push around the other robots. I would like to use one of my 12v gearmotors instead of the ones contained in servos, but I don't want to destroy my servos to do it.

Topic by Stingray    |  last reply


LED Phototherapy Circuit

Hi,We are a non-profit organization (www.spiritusvitae.org) that focus on infant and maternal health care, we are implementing our programs in the Philippines. One of our programs is all about Jaundice, we are seeking help in this community to help design an LED Phototherapy unit that we could build easily less costly and this will be donated to the hospitals that are in need of these devices.Please see attached photo of the phototherapy device that is used in one of the hospitals, just to explain it is really not phototherapy light but a simple blue fluorescent bulb has very low effect for the babies.We hope that this community could help on this matter.Thanks.Vins

Topic by global.spiritusvitae    |  last reply


LED matrix circuit?

So I am trying to make something like this: https://sites.google.com/site/gradcapmod/   to basically make an LED display on a cap. The thing is, I don't want to program anything, just light up a design, wired with a switch to turn on and off. Most instructions are how to program a display using a microcontroller and transisters, etc. My plan is to use 3mm leds and just solder them together and power it with a 9V. Would that be feasible, wiring the LEDs in parallel strands. Also, I know that I might want to use resisters to make sure the current isn't too high and burn out the bulbs but I'm not sure where to put them in the circuit or how to calculate it. (I can't make a circuit from looking at a schematic either)

Question by AeroGophers    |  last reply


what is the best free software to design electronic circuits? Answered

I need a free software to design electronic circuits.. before i execute them on a breadboard or a strip board.. online software is also fine..

Question by Karthik Raj    |  last reply


Any good free electronic circuit design programs?

Hi, i'm a second year engineering student in need of free tech!  Can anybody recommend a decent circuit design program? I have access to programs like this at university, but thats 6 miles from my home and me and my brother want to build a electric bike. Thanks to all that can help =)

Topic by Tsimbilakis    |  last reply