Electronic – the difference between optoisolator and motor driver

opto-isolatorrelay

Suppose we need to control power of a device (12v, 500mA).

I tried to use TLP281 board, which works, except that it inverts the output: device is powered when there is no control signal.

For this reason, the TLP281 board is not useful in my project.

This is picture and schematics for TLP281 board:

enter image description here

enter image description here

enter image description here

I need an optoisolator board which works analogous to normally open mechanical relay: when
there is no signal, device must not be powered; and when
there is signal, device must be powered.

I consider to use ULN2003 arduino board instead of TLP281 board. Is ULN2003 supposed to be used as a relay at all?

NOTE: workaround by inverting the control signal in microcontroller firmware is not permitted, as the device must not be powered when microcontroller is off

Best Answer

The board has additional discrete transistors to invert logic (signal on the input pins is reflected on output pins), stand alone TLP-281 sans discrete transistors may solve your problem....More curious about your load, thought current was limited to 50mA, you imply it works with 500mA?

Related Topic