Drop Target Reed Switches.wmv

Pinball Lab. Let's see what's on the slab...
The problem with horseshoe contacts on Williams Drop Targets is they wear out the copper traces below and need adjusting. In my experience they can become unreliable right in the middle of a good game, which ruins it. To address these problems, I stated thinking of using reed switches and tiny magnets glued to the back of the targets. My ver #1 prototype, more of a "proof of concept" is working quite well and shown in this video clip.

The 3 powerful magnets came from the back of a name badge, where you have a metal strip that goes behind the lapel or inside a pocket to hold it on. Maybe someday I can produce a modular replacement that would be excellent for Williams drop target repair.

Things that still need to be tested:
Immunity to magnetic "noise", switches being triggered by DT resets or other solenoids or magnets. Optos would be better for this, but more complicated as the circuit is not passive which this solution is. For each target, there is a small magnet, a reed switch and a diode and that's it. You drop it directly in the matrix, like any other switch and it works.

Also could the solenoid's magnetic field "demagnetise" the little button magnets over time? I don't know and would have to test a prototype for some time to prove this doesn't happen. One good thing is that the magnet would be glued to a flat copper spring on the back of the target, and that strip is non-magnetic which should help.

I plan to make some on veroboard for my Williams Flash and see if they are reliable.

-Richard

Category:

Gaming

Tags:

• pinball drop targets
• Flash
• Gorgar
• Firepower
• Black Knight
• Jungle Lord
• Pharoah
• Solar Fire