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Topics - brazdj

#1
Hello!
I have the Pinball all done on a breadboard and my op amp voltages do not quite match those that are posted. The only pins of concern are the non-inverting pins downstream of a 2M2 resistor, so: Vb -> 2M2 -> Pin 4. I am getting a voltage of ~ 1.7 whereas the Pinball pdf states a voltage of ~ 3.54.

Granted I do not have all of the components for a true Pinball. I am skipping to a true bypass configuration so I exclude most of the Power & Switching components. I do include the 1N5817, the Inductor, the zener diode, both 0.1 uf caps, and the 150 uf cap. So my voltage on Pin 8 of the op amp is ~ 8.9 V (coming from a ~ 9.4 V DC One Spot). My Vb voltage is therefore ~ 4.45 V.

How is the current on the PCB being limited such that the 2M2 resistor only drops 0.46 Volts?

Thank you for your time,
Daniel