using a current sensor to "brake" a motor

[KenWittlief]

that is a neat idea - you would be slightly powering the motors backwards to keep the winch motor stalled and not turning

but if you know the power will be off at the end, then what is the application you have in mind?

I recommend that every team that is planning a doing a chin up have some sort of self latching mechanism that locks into place, once you are off the ground, so that it will stay put when power is cut.

another thought: if you are planning on using this during a match for some reason, use a variable control on the OI, a potentionmeter - that will allow the driver to adjust how fast the winch pulls in, and it will allow it to be powered just enough to hold it in place - I still dont know why you want to do that, but it can be done.