What size of potentiometer is required for 12v 2A battery

 Would like a potentiometer that one position is off, and then turns all the way (gradient) to full power am also looking for something that is as compact as possible thanks for any advice! Oh and would I require any other circuitry to regulate the electricity from the battery! Thanks a million

Hi,

Well generally, you need a 6 Ω resistor so that it will work. For the size, that totally depends on the wattage it can handle.

You have not described your requirement fully and I can see what the other contributor is trying to say.

Basically you need

uxcell 25W 10 Ohm Ceramic Wirewound Variable Resistor Rheostat

for about $10.00

It is also worth mentioning that if you use a potentiometer/rheostat to control the load, you will be using a significant amount of your battery power to generate heat in the potentiometer.

There are several other possibilities for controlling the load, but selecting one requires knowing more about what you are trying to accomplish and what the load is. You might look at a hobby brushed ESC (electronic speed controller) if you are controlling a motor. These devices use a PWM controller to quickly turn the power to the motor on and off with a duty cycle proportional to the desired speed. Since they turn on and off rather than use a series resistor they produce relatively little heat and will significantly extend your battery life (unless you almost always run at 100% speed in which case it wont make much difference).

Edit: I saw your user name, if you are trying to control a solenoid or motor driven tattoo gun, take a look at the Brushed ESC solution. You will need a "servo tester" to generate the PWM signal needed to control the ESC.

Servo tester: https://www.amazon.com/Digital-Tester-Consist...8&qid=1476366826&sr=8-3&keywords=servo+tester

Brushed ESC: https://www.amazon.com/Bustophedon-Brushed-Sp...8&qid=1476366887&sr=8-15&keywords=brushed+esc

If you are going to try this, post a note and I'll post a diagram explaining how to connect these devices.

Second edit: don't order that ESC, you need an ESC rated for "4S" for lithium-ion use (so it will tolerate the 12V power supply). These are common on Amazon and elsewhere.

Thanks for sharing, this is a fantastic forum.Really looking forward to read more. Keep writing
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