I have asked a similar question a couple of months ago but I need some more help now, as I need to eliminate all external switches and wiring.
Here it goes:
I have a 12v linear actuator (max 4 amp @ max. load) with built-in internal end switches that stop the motor at the end of it's travel. The extension/retraction is controlled simply by reversing the power supply's polarity.
Now what I need is a circuit that with a push of momentary push-button will run the motor and extend the actuator's arm all the way out, then as soon as the end point is reached and the current flow through the motor is stopped, it would sense that and reverse the polarity in order to retract it all the in, until the other end point is reached and the motor stops again.
Ideally holding the push button constantly in would repeat the whole action, but if it doesn't and I have to release and depress again - well... I can live with it...
I though about using the 555 in bistable mode and sensing the voltage across an in-series to the motor load, small value resistor for the trigger, reset but I am sure there is a more elegant solution out there...
Ideas, please?
Dimi
Here it goes:
I have a 12v linear actuator (max 4 amp @ max. load) with built-in internal end switches that stop the motor at the end of it's travel. The extension/retraction is controlled simply by reversing the power supply's polarity.
Now what I need is a circuit that with a push of momentary push-button will run the motor and extend the actuator's arm all the way out, then as soon as the end point is reached and the current flow through the motor is stopped, it would sense that and reverse the polarity in order to retract it all the in, until the other end point is reached and the motor stops again.
Ideally holding the push button constantly in would repeat the whole action, but if it doesn't and I have to release and depress again - well... I can live with it...
I though about using the 555 in bistable mode and sensing the voltage across an in-series to the motor load, small value resistor for the trigger, reset but I am sure there is a more elegant solution out there...
Ideas, please?
Dimi