SparkFun Forums

[mechatronics]

Hello, I am relatively new to circuitry, but do have some prior knowledge. What i want to do is power 4, 6V motors from the 3.7 lipo batteries. What can I do to get a constant 6V from these batteries. I have heard that some kind of opamp circuit may work. I am open to any ideas and/or parts. Thanks for your help!

[Liencouer]

How much current do you need for the motors?

[Blackfin]

Op amps (or "operational amplifiers") are not power amplifiers. They generally work to perform mathematical operations (e.g. summing, integration, differentiation etc) -- which BTW, is where the term "operational" comes from -- on low-level, low-power circuits.

To generate the sort of voltage you need you have a couple of options. First, you could run 2 of the LiPos in series to generate ~7.4V. I'm sure the motors won't care if they have 7.4V applied instead of 6... Second, you design what is known as a "boost converter" -- a fancy way of saying a power supply capable of producing an output voltage higher than the input voltage.

But as Leincouer asked, in order to help we'd need to know how much power -- we know the voltage so you need to tell us the current -- will be involved.

[mechatronics]

Hello, thanks for responding. I am looking to power 6 motors, they are the ones similar to the magician chassis ones, 2 servos, and probably 200mA of miscellaneous stuff. I am just looking for the best way to do this. I will be using an Arduino Mega and possibly an Uno too. The motors want a 6V power source, though 7.4 would probably be fine. I just don't want a decreasing voltage source (its what is happening with batteries I am currently using I think).

Thanks for your help!