I have one of these led projectors which is normally powered by the embedded motion sensor.
I want to be able to power it manually by a switch button. I need to do this in both alternative and concurrent mode. By alternative I mean that the projector is turned on either by the motion sensor or manually by myself; by concurrent I mean that it is turned on by both at the same time.
In order to achieve this I can follow two these strategies:
- simulate a motion detection by providing the control circuit with the same signal provided by the motion sensor;
- power the projector directly.
I have opened the device and have found out the following:
- the projector is powered by a 22-25VDC power supply provided by the control circuit.
- out of the motion sensor come out three wires which are fed into the control circuit. I have yet to investigate what do each of this does.
In both cases the difficulty I have is protecting the existing circuit from voltages and currents generated by the power I supply myself. I think this could easily happen in the concurrent mode.
How do I deal with these two inputs?