I have a question on building this EM circuit tester.

https://www.funwithpinball.com/resources/bulb_tester

For a 25V circuit, instead of using the 4 bulbs, could a single bulb and a power resistor be used? This would mimic the setup on the Ship Ahoy WOW lights on either side of the spinner where a single 44 bulb is run using the 25V bus.

Second question, I saw in the video on the link above how the tester was used across a coil. Could the tester also be used if connected one lead of the tester on the 25V side of a switch and the other lead to the Common return?

Thanks

Alberto

Thanks gentlemen, this is being built to try and fix an intermittent issue with a Gottlieb 300 that I just can’t figure out.

I’ve posted about it before, this machine randomly gives extra balls. There is no pattern at all. I’ve tried jumping over different switch combinations with no luck.

This tester should help me see where the intermittent connection in the Add Player Unit circuit is.

Once I get this built, I’ll revive that thread.

Alberto

MarkG I plan to use banana plugs on it so then I can use any length lead I need. I’ll have to post finished photos of it

Thanks again for sharing this knowledge. It’s people like you, HowardR, dgAmp, DaMoid, LeckMeck, etc that make the EM board awesome.

Alberto

Finally built it. Used a shallow wall box, a couple banana plugs, a lamp socket, and a power resistor.

I’ve been playing around with it to understand how it works before using it to debug my buddy’s 300.

For example, if I wanted to check the working of the Lock Relay on this Williams Set Up, would I place the tester across the coil lugs? Then when I hit the left flipper button that is when the bulb would light, correct?

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