Hi John,
Yes, sure. Whether you really need it depends on the size of the power supply. I would use a 100VA transformer and a 10A bridge rectifier, which is more than adequate by itself to throw any ordinary points-motor. If you have a smaller supply you can beef it up by adding one or more capacitors in parallel with the rectified output. They should ideally be rated at least 35volts and designed for high-ripple currents, but it depends how rugged a system you want to build. Make sure the supply's bridge rectifier is good for at least 50volts PIV, preferably 100volts.
The circuit at:
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also requires only two wires per points-motor. The third connection is to the layout ground (common return) which already exists on each baseboard. If you prefer a separate return for the points-motors, that is still only one additional wire per baseboard. There's no real need, providing the existing return is done with good thick wire, as it should be.
regards,
Martin.
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