AC to DC Conversion Circuit

Are you talking a simple bridge rectifier with a polarity reverse switch?   I'm pretty sure that the toggle switches would have been DPDT, you'll certainly need that for polarity reversal.

This should be pretty simple to draw up...

@trains52 posted:

A number of years ago I saw a wiring diagram for an AC to DC conversion circuit using a bridge rectifier in one of the Train Magazines, using 2 SPDT toggle switches one for AC to DC selection and the other toggle switch for Forward and Reverse selection on the DC side. I have broken wires on my unit and am not sure how to rewire. Does anyone have a wiring schematic for such a circuit as I have long lost the article with the original diagram on it. Any help would be greatly appreciated. Thanks Gary.

So minor issue- there are ways to wire this but I see some conflict

Edit- John beat me to it!!

Example, you said bridge rectifier but then also said 2 SPDT

I could use individual diodes, not a bridge for half wave, and use a SPDT switch- and get 2 polarities.

That same circuit above using half wave then also leads to easier DC to AC switch use of another SPDT switch.

However, I see a more effective circuit using 2 each DPDT switches and bridge rectifier for both full wave DC both polarities, and the other switch going between AC and DC.- but again, that key point is DPDT switches.

I think the bridge rectifier with full-wave rectification makes a lot more sense, half-wave rectification will create a very noisy running of some DC motors.