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.

John, they are DPDT switches, here is a picture of the box I wired years ago. Switches on mine look different than on your diagram. Switch on the left is AC/DC on right is Forward/Reverse.

Gary

I'm not going to try to follow the wiring from a picture, but my wiring diagram will do the task you are talking about.  You asked for a wiring diagram, I provided one.

One switch selects either AC or DC on the tracks, the other switch swaps the polarity on the rails.  I believe that was the object of the exercise, right?

Based on John’s schematic and your picture, I would start with this. But double check.

@gunrunnerjohn posted:

I'm not going to try to follow the wiring from a picture, but my wiring diagram will do the task you are talking about.  You asked for a wiring diagram, I provided one.

One switch selects either AC or DC on the tracks, the other switch swaps the polarity on the rails.  I believe that was the object of the exercise, right?

John, respectfully, shouldn’t some capacitors be in there to smooth the DC voltage? Technically, what you have will work but the DC voltage might be a little choppy.

Steve

@RideTheRails posted:

John, respectfully, shouldn’t some capacitors be in there to smooth the DC voltage? Technically, what you have will work but the DC voltage might be a little choppy.

Steve

Well, if you look at his box pictures, no caps were used.  To just run a DC motor, you don't need any caps, if you're running electronics, you'd probably want some filters.  Easy to add, just put them across the output of the bridge rectifier.  A DC can motor will run fine on full-wave rectified DC with no filtering.