MK120 Light barrier from 12V DC power supply

Kits Mini Kits Range
1

I have MK120 Light barrier and it works fine, I would like to run it from 12V DC power supply.

These are given specs:
transmitter emitter: 9Vdc, 50ma max.
receiver detector: 9Vdc, 20ma max

So to run at 9V DC I need to add 43Ohms resistor in series to get 9V from 12V?
Or can I run them from 12V directly?
Or perhaps it’s better to change some resistors on PCB, if so what components needs to be changed?

Thank you.

2

It is OK to run both units from a regulated 12V source.

3

Thanks I will run them from 12V then.

I have another question:
This detector will be used when the transmitter and receiver LEDS are close together 2cm.
How can I adjust sensitivity? What resistor needs to be changed with POT to adjust it?

Thank you.

4

There is no need to adjust the sensitivity.
Putting the transmitters and receivers in a small tube can help to make them more directional.