Let's Make Robots!


The LM-317 Voltage regulator problem

Well, recently I have been attracted to laser diodes. I am trying to make them work. Here is what I learnt-

1. LASER diodes are pretty current hungry,it will eat as much as it gets,since it's internal resistance is pretty low.

2. To make LASER diodes work properly, you need a CONSTANT current source.

3.Red Laser diodes need 3 - 4 volt to run.

4.You can make a Laser driver using LM-317 (it's called DDL)

Mind the Raspberry Pi power usage

The RaspberryPi is a powerfull little gadget that can add a lot of good features to your robot. For under $60, including cables, dongle and SD-card, you get a lot of processing power, data storage, wifi and audio. So I ordered a RaspberryPi to be used as the brain for my R2D2 project.

Too much capacitance?

Is there such a thing as too much capacitance in a voltage regulation circuit?

I plan to use a pair of  47 uF 50volt caps in my power supply - 'cause that's what I have in my

junk box.  Any problem?  (It will be powering 3 Picaxe08-M's and a L293D motor controller. - power for the motor will be separate)

How do I determine the 'proper" amount of capacitance?

Voltage regulators in parallel

Hi guys, i'm planning to make a robot which requires 12V,5V and 3.3V power lines regulated from a approx. 15V battery.Would it work if i used 3 voltage regulators(one from 15 to 12V,one from 15 to 5V and another one from 15 to 3.3V) connected in parallel? Or is there another way of getting 3 different regulated voltages from one power source (the 15V battery) thanks. 

5V and 3V together


I'm building a board that needs both 3v and 5v as it has some components working on 3v and others on 5v. Now what is the best to do in this case? I am not sure, i've analyzed some of the options but i really do not know the advantages/disadvantages of each:

- have a 5V regulator and a 3V regulator with the input connected to the 5v reg's output (could be done, the 3v reg is low dropout)

- have a 5V reg and some diodes to output 3V (or a voltage divider with resistors)

- have a 5v reg and a 3v reg with both inputs connected to the v+ on the battery 

Arduino voltage regulator and other questions.

 Hello, I have a few questions I hope somebody or several people can answer :)


The KA378R05 is a low-dropout voltage regulator from Fairchild Semiconductors. From the page, "Dropout voltage of KA378R05 is below 0.5V in full rated current(3A)". … Read more

5v voltage regulation.

Is there a simple thingy that I can hook up to any voltage higher than 5V (within reasonable range) and always get 5volt out?

Building the perfect robot power supply

One thing most robots need is a power supply that can put out a reasonable amount of current for servos and other small motors as well as run a processor and sensors. Probably the best setup is 5x 1.2V NiMh cells to provide 6V for motors and servos with a low dropout regulator providing 5V for the processor and sensors. Unfortunately this isn't always practical. Sometimes you have motors that need higher voltages or maybe the only battery you have lying around is a 7.2V battery from a RC model.

Price: $15 USD
I have yet to order one, but these things are amazing! They take a input voltage of any value between 6.3V-30VDC and it outputs a steady 5VDC at up to 1A of power! Read more
Recently I've noticed some people are a bit unsure of how to regulate their robots batteries and since there was a tip/walkthrough on batteries recently I though … Read more
5V Regulators Being stupid I can never find out how much resistor and what do i know I would need to get my 7,2V Racing pack battery to turn in to nice 5V that my … Read more