The series continues as Michael describes more of his time at the Exploratorium. Be sure to catch up on his other posts.
The problem for this week is a set of buzzers that the kids activate by pushing buttons as part of a storytelling exhibit. The buzzers keep going bad. After a little testing I found that the low quality transformer is providing way too high a voltage. I reduce that with a lower voltage switching power supply. With some further poking around I conclude that there is still a lot of arcing at the contacts of the buzzers so I added a crossover Zener and a blowback diode to dissipate inductive current from the coils. This has solved the arcing problems but there is still the matter of failure due to fatigue. What to do…what to do…what to do…? When you need inspiration at the Exploratorium you wander around with a cup of coffee and look at other peoples projects and fish for suggestions and this time I landed a good one.
After a few phone calls to arrange a meeting, I am off to Alameda to meet with Michael Schiess, the Executive Director of the Pacific Pinball Museum, because if there is one place that will have buzzers and bells that can take a beating its going to be pinball machines. What a great place. It ranges from the very old purely mechanical type machines and slowly works its way up to the most modern machines with monitors in the back and very complex interaction with the player. Michael is a fountain of knowledge on the subject and very enthusiastic, the kind of enthusiasm that is easy to get caught up in. Since these machines reflect the popular culture of the time in which they were made, walking through the museum is like a trip through the popular culture of the U.S. for the last 80 years. While I ultimately got a lot of good information to help me replace the low quality frames, solenoids, and clappers of the old system with high quality industrial ones, what I really got was an education on how we as Americans see ourselves through our entertainment.

