[landslide1]

I'm about to try and hook up a probe to my old 0m-a.

I have found the skip input and tested it. I used 24V+ and connected it to the skip and it triggered.
the 24V was coming from a connector for hooking up external devices. I accidentally shorted the pin and it blew the main 1A fuse on the 0m-a mate board.

obviously the skip input has some current limiting ability or the input would blow the power supply also.
I probably should just measure the current draw, it but it's always good to get some other knowledge first. anyone know what the current for an input is?

I'm need to reverse the probe switch logic and I'm going to add an led for visual trip indication. I'm a bit worried the 1A main power supply wont have the capacity. I'm looking at around 3-5mA + the skip input. I don't have a wiring diagram but have been poking around in the cabinet but can't find a better 24V source. is there another common place to find 24V source?

thanks

[tc429]

should be anywhere...on a zero, the source usually comes from pin 33 on M1/M2(I forget which) but should be a bunch of terminals for it in the panel...look at your drawings for the common wire to your overtravel/decel inputs, , likely numbered +24, 24P, 2240, something like that depending on OEM... the input draws almost nothing, think they all use a 3.3k load resistor to ground. we did some rough probing on some ugly castings, rather than a real expensive probe, used a 20 dollar 914 series(914-ce2-3k comes to mind, it had a roller tip) microswitch, repeated within .001 , didnt drift more than .005 from new to well worn.