JohnGaltLine posted:...On the last point, The switch machines won't care if they get half-wave power or what the peak voltage is. They only care about the average, or RMS voltage.
I need to disagree here too. I assume we're talking about those solenoid-coils that push/pull a steel pin to throw the switch?
The current flowing in the coil generates a magnetic force proportional to the instantaneous current. A solenoid can do its thing in a fraction of a second. Consider the example values shown above for the one-diode method. The average voltage applied to the solenoid would be 7.2V DC. If this were a steady (non-varying) 7.2V then the coil will have a fixed (non-varying) current of some number of Amps generating a steady magnetic push/pull on the pin.
But this 7.2V DC is really a pulsed half-sine wave that peaks at about 22V DC. So for brief instances the Voltage jumps up to some 3 times the average voltage. And at the peak the force generated by the solenoid also jumps up to 3 times whatever force was generated by that steady (non-varying) 7.2V. It is during this peak pulse when the job gets done by the solenoid.
So bottom line, the solenoid does indeed care that the 7.2V DC has a peak voltage several times that. I suppose one could experiment but I don't think a fixed 7.2V DC will reliably fire the typical solenoid-coil switch machine. Maybe someone knows.
