I agree with Pinhead, I would add another lower current coil that triggers off a new switch added to the pop bumper relay switches. This would also let you add a separate fuse to the topper if you desire.

With the extra switch on the pop bumper relay switch stack you then don’t have to use a DC coil with a diode, you can run the Tommy Gun coil off one of the AC power rails.

One more suggestion, if this is for a topper, and you want to run it off a pop bumper, you would then need to run wires (and a connector) from the playfield up to the head. What if instead you triggered off one of the point scoring relays which are already in the head, making the topper installation perhaps less involved?

Love the idea, BTW

Alberto

I think this is the suggestion, add an extra switch to the 10-pt Relay, add a fuse in series (the fuse is probably optional), and connect your Tommy Gun coil, fuse, and switch to the +50V rail and it’s return path to the transformer.

Every time 10-pts is scores, you get the Tommy Gun.

Adding a connector is a great idea.

Regards

Alberto

BB403860-487D-4EB0-94FD-1884DCEF9313 (resized).jpeg

I don’t have an Old Chicago to reference but hopefully the 10-pt relay has an open slot in its armature so adding the extra switch requires minimum changes to the hardware.

Mopar
I see what you are saying. You are suggesting to parallel the two coils like below (green arrow). That would also work. One concern would be the current going through the coils would now be half for each, would that be enough to create a magnetic field strong enough to move the metal plunger?

Please ignore the fact that I’m connected in parallel to the 10-pt chime coil, it should be the 10-pt relay coil.

Alberto

DD28517F-3F84-4B10-B109-E1F570A4C4DC (resized).jpeg

Mopar and at @markg, I think you are both correct. I think I was diving too deep into this one. The Tommy Gun coil connected in parallel to the 10-pt relay coil in the head should do the trick and keep the mods to a minimum.

Alberto

To use the coil 50V to power up a 6V LED, you would need to burn a lot of power with that resistor. You’d have to burn 44V, you would need a big power resistor (high Wattage rating) and it would still get pretty hot.

I think a second power rail going to the gun for the LED would be better.

Regards

Alberto