I am building a project that simplifies a dolly moving on a track. When the dolly reaches the end of the track, it triggers a microswitch that cuts the power to the motor, and redirects the power to a LED to light up to indicate that the switch has been triggered.
My problem is that since the motor controller I am using changes the polarity of the motor to make it go left or right, I am getting positive and negative voltage every other time. (depending on if the dolly is moving right or left). I have tried to use a 12V relay to trigger and light the LED, but the problem is relay needs at least 6 volts to latch, and when the motor is running slow, the motor controller only provides 3-4 volts.
Is there anyone that has a solution on how I can make this work? I am just starting to fiddle with electronics, and I am on a budget with this build, so therefore: Is there a relatively easy fix for this problem? Are there relays out there that has a latch range from 3V to 12V?
Schematics of the circuit with the LED (and resistor) connected directly to the microswitch. The problem here is that every other time the positive and negative switches.
Schematics of the circuit with a relay attached to the 2nd output of the microswitch. The problem here is that the relay need 6 volts to latch, and the motor controller doesnt provide that at slow speeds.