Cutting the power to the DC Motor after a predetermined amount of time?

W

Thread Starter

Winson

I am supposed to stop my prototype after crossing a reflective tape but somehow my IR emitter and detector screwed up.

Can anybody suggested any circuitry to cut the DC motors of my prototype after a predetermined amount of time (~1-2 seconds)?? would appreciate greatly for some advices.

Thanks dudes...
 
K
For something around 1 to 2 seconds you could do it with a safety relay. Lots of companies make them, but Omron serves as an example.
 
An RC ciruit connected to a schmitt trigger gate input can be as delay circuit. The delay time increases as the time constant RC. Eg. 50 kOhm x 100 microF = 5 second. Use a variable resistor to adjust the delay time.
 
I am assuming you have no controller on this mechanism, else I would use a timer in the controller.

Without a controller, try using a better sensor in combination with a "Just-in-case" timer. Usually having both can be advantageous. Sometimes a fixed time delay can get you in trouble if you have no feedback, but I am not sure of your complete application.

~Ken
 
C

Curt Wuollet

Google 555 timer. You might need a series pass transistor depending on your motor current. You will find hundreds of application circuits.

Regards

cww
 
M
Simplest solution - use a timer relay (e.g., from OMRON). To play with electronics, use the good old 555 chip.

Meir
 
You can buy several inexpensive solid state timer relays from Allied Electronics. A time off delay is what you will need and the time is controlled by soldering in your own resistor.
 
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