Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: SeagullOne on December 19, 2007, 08:39:39 PM

Title: Adjustable voltage regulators
Post by: SeagullOne on December 19, 2007, 08:39:39 PM
I have a question that's been bugging me for a while.

How do you adjust adjustable voltage regulators? I'm going to begin the electritronics portion of my robot soon and I'd like to know how to use those.
Also, going back to my 5V-10V planetary gear motors (I'm not sure how much they'll draw. Their stall current is 17amps and there's no chart to go with them), what capacitors would any of you recommend I use to cancel out the electrical noise?

Thanks.
Title: Re: Adjustable voltage regulators
Post by: ed1380 on December 19, 2007, 09:01:25 PM
datasheets. use them.

IIRC most use a resistor
Title: Re: Adjustable voltage regulators
Post by: airman00 on December 19, 2007, 09:03:16 PM
they use resistors
Title: Re: Adjustable voltage regulators
Post by: paulstreats on December 20, 2007, 07:16:16 AM
The cheap ones, you have to connect a resistor between 2 of the legs - the resistor value you use depends upon what voltage you want. It should be in the datasheet.

The more expensive ones usually have a trimpot built in that you just turn (the even more expensive can charge pump above the input voltage)
Title: Re: Adjustable voltage regulators
Post by: SeagullOne on December 20, 2007, 12:51:45 PM
Wow, I didn't know individual electronic components had datasheets of their own. I always just saw them lying around in bags at Radio Shack I've been wondering how to do it.

As for capacitors, its best to use 100uf for about every 250mamps. So at say 8amps a motor, I ought to use 3.2f capacitance for each motor. I probably ought to put some close to the batteries as well. What do you guys, think?