This Massive board is so heavy it is only possible for 2 people to lift it with the doors off. It delivers a 30 sec alternate polarity pulse supply to the slave clocks . It’s designed to work on 40 volts and draws a current of approximately 15 amps when fully loaded .It was designed to operate a staggering 2000 clocks . It was build in approximately 1965 . It’s going to be a long term project and unfortunately one of the polarity changers is missing. That in its self is going to be a challenge to find (unlikely) or most probably make a replacement. Andy 
