The Ben Heck Show

Mini Pinball: Project Mockup (1) (7x9)

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In this episode The Ben Heck Team takes a look at the original pinball machine so they can rebuild it as their final long term project for the year. The original Mini Pinball machine was built to a 1:2 scale of an actual pinball machine but there wasn’t very good control to prevent the ball from flying all over the place. The original mini pinball machine used a Teensy 3.2 MCU and a lot of hand-soldered components. The major parts in the original unit are a battery, an audio SD card that could be replaced with the 12-bit DAC built into Teensy 3.6, a volume knob that can be removed, and a start button that can be removed as well. After analyzing the original pinball machine, Ben and Felix test out 8 different sizes of balls. The original ball they used for their pinball machine was too light and floaty. The surface mounted MOSFET Ben looks at is n-channel 80 volts and 39 amps which should be plenty for this project. A MOSFET is a metal oxide semiconductor that can switch powerful loads. After that Ben and Felix take out there meter to measure the charge on various battery packs. Felix breaks out a breadboard to do some solenoid testing. The hope is that they can use one size of small solenoid for everything on the mini pinball. Felix goes over a circuit diagram of everything they’ve wired up. It has 12 volts coming in, the VVD has 12 volts coming in, a diode, a solenoid that goes into the drain of the MOSFET, a switch that’s going to 5 volts, 5 volts comes into the gate, and there is a 10K pulldown resistor on the gate as well that goes to ground, and then the source of the gate goes to ground. The MOSFET allows them to control high current loads with regular TTL level signals (like a MCU). While Felix mocks up a MOSFET test, Ben works on physical stuff such as what type of ball will work best. In the earlier project Ben was really hung up on making it to scale like a pinball machine but comes to realize that was a mistake because the physics d