programming a dc motor to reverse direction on a timer

Other Hardware Motors, Mechanics, Power and CNC
1

Hi there,
i have a 12v dc motor that i am using to spin a string from a fixed point (for a larger application). essentially, i need a switch or controller that allows me to change the direction of the motor after a certain amount of time, right before the tension of the string becomes too much and the motor fails. i don't know much about electronics and i'm wondering what is the simplest way to achieve this, and what exact info/products are there that can aid in doing this?
thanks for any help!

2

I'm not sure what "spin a string" means, but if you want to monitor the load on a DC motor, measuring the back EMF is one way to do it.

3

tpkd:
Hi there,
i have a 12v dc motor that i am using to spin a string from a fixed point (for a larger application). essentially, i need a switch or controller that allows me to change the direction of the motor after a certain amount of time, right before the tension of the string becomes too much and the motor fails. i don't know much about electronics and i'm wondering what is the simplest way to achieve this, and what exact info/products are there that can aid in doing this?
thanks for any help!

H-bridge.

But first tell us exactly what motor you have, so we know if its 100mW or 20kW (!)