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power supply

Arduino motor control problems!


Update 06/11/2016

Hey guys,

I sort of got the motor working. Adding a small resistance(about 2-3ohms) in series with the motor seemed to stop the Atmega reseting whenever Pin 3 was pulled HIGH (still don't know for sure what was causing this!). I'll still continue t troubleshoot this problem and completely figure out what exaclty was causing the Atmega to reset, since the resistor is not a permanent solution (wasteful energy loss). I'm really grateful for the huge amount of help from here guys!! Thanks alot! :)


General use, very useful for bench testing, power battery chargers and testing of prototype robots.
This project involves adaptation an ATX power supply for computer, often found in junk or very cheap cost, but offering an excellent power supply with standard … Read more

12V-30V Arduino Power Supply

So one project that I've been working on lately is a 24V Brushed Motor Controller Shield for Arduino. One of the features that the shield must implement is a power supply capable of power the Arduino with more than 15V, activates the Arduino when the input voltage is greater than 12V, and power any necessary gate driver circuitry. I finished Rev 1 of the power supply and plan to add one more revision to the power supply circuit before designing the reminding parts of the shield. 

A week ago I had the idea of building another lab supply. MetalmonkeeLad (Keith) suggested sharing it with the LMR lot so here we go. Read more

School fund raiser project.

I've been asked to do a small piece as a fund raiser for my Son's School - the idea is to make some small 'bots which will run around a course, either randomly then stop or round a fixed course for a random period of time (say 30 secs to 1 minute). I'd originally thought of bristle bots they're fun , quick to make and cheap - maybe 2 side by side linked "catamaran style". Ideally I'd work with the 10 yer olds to make them.

The idea is that they'll be used to select winners for a prize - pay fifty pence, if your bot stops on a prize winning square you get a prize!

many little motors, many power supply questions

Hi all,


I am new to this forum but i have stalked users of this site for sometime.

I have a project on the go that i am a little stuck on. I have come pretty far since the idea hit me many months ago but now i am at the tail end and wondering how i will power this thing.

I have been using an Arduino connected to a bunch of 595 shift registers which are then connected to 36 small dc motors via npn transistors. the motors are small mobile phone vibrating motors and i need them to run, as per datasheet, 3v @ 90ma.


CNC electronics

I'm in the process of building a CNC machine right now and would like a little help from the experience ones.  Right now I have $250 saved up and counting.  I'm trying to figure out what to do about stepper motors, power supply, and motor controller.  I didn't know if it be best to just buy a package that have it all in one and what would you recommend.

I am confused about how to use LiPo batteries

Hi all,

I am currently working on a new robot and I will soon have to choose a way to feed it with power.

I've been reading about LiPo batteries, but I am still confused about how to integrate this kind of power supply in a robot. Here are a few questions I have in mind :

Portable breadboard and power supply.
-EDIT- I reread this post, and it didn't sound at all clear... so I re-wrote it. Read more

Power regulation on 24V system

I need some ideas for deriving power for the electronics and servos on Yard Gnome. YD has a single large 24V motor that is powered by two 12V batteries in series.


One battery or two?

What do you guys think?


Seperate power supplies for the motors and the µC or one batterij and some electronics to reduce the voltage :

9V for µC and 6V for motors

Reverse polarity protection for Maxsonar sensor

Hi guys,

This is an image from the Maxbotix site, a circuit recommended for removing electrical noise. I was wondering whether it is safe to replace the 100ohm resistor with a diode (with a low forward resistance), so that it can double up as a reverse voltage protection element.. ?


Image from Maxbotix


Price: $11.05 USD
I bought this great Power Supply Kit by Chaney Electronics from The Electronic Goldmine. It is rated for 0-12V. My kids managed to pull mine off the table and … Read more

Powering Arduino and servos/motors with one supply

Helo, all

I tried to power Arduino (Duemilianove) and servos/motors it controlled with the same battery, but Arduino continuously restarted during the operation. Actually it was a surprise for me, since Arduino already has voltage regulator chip and filtering capacitors in the input circuits...

I solve this problem by supplying them with different batteries, but I don't like this solution. Could anyone help - how to provide single power supply?

Filtered Linear Power Supply

I was wondering on a site about wireless video transmission, and ended up on this power supply board:


Isn't it very very interesting?? 10 bucks and you have a selectable 3.3, 5, 12 output voltage with input between 4 and 35 volts!

Is there something i'm missing or is it very cool?

Provides power for breadboarding, testing, etc
I was tired of wasting batteries while testing my robots and other circuits, and having to dig out voltage regulators every time I needed 5v or 12v for a circuit, … Read more

Which Battery Pack for the PICAXE 8 Pin Proto Kit? (9 volt?)

I just received the PICAXE 8 Pin Proto Kit from Sparkfun (yay) and it comes with what looks like a 9v battery snap clip but the datasheet says that I cannot use a 9v battery.  The text states:

"ONLY USE A 4.5V or 5V battery pack, not a 9V PP3 battery, as the power supply."

So what kind of a 4.5v or 5v battery packs uses the snap type connectors?