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I wish to use a 1054 Frequency Counter to measure the frequency of a flashing 24vdc lamp. More accurately, the 24vcd is pulsed at either 4 or 8 Hz and I wish to measure that rate.

The question is, rather than use a relay, I wanted to just use a voltage dropping resistor to get the signal below the 20v max input voltage. But, in order to calculate the right value, and I realize I have a large target range (3v to 20v) I need to know the current draw of the 1054 input.

I looked on the product page but couldn't find this information, though I assume it is very low, probably <10ma.

Any help appreciated.

The positive input has around 500K Ohms, so putting a 500K resistor in series would drop it by half to around 12V

Thanks.