Quote Originally Posted by Boyan Silyavski View Post
Absolutely right. Here below is how to check if that is the case / credit goes to C23 BOB manual/

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Useful post Boyan. Applied the formula to the NPN I had with the external 2.4K ohm resistor I used and got answer of 10.4K ohm for the switch internal resistance. This seems consistent Clive S post. The switch does have 300ma printed on it. But I think this is too much current for the BOB input. So back to the Neale's suggestion. Will let you guys know how it works out.