Capacitor Discharge unit

[Goathingham]

As someone who considers electrics the "Black Art" I have two questions:

1) Can I power my Peco point motors from the DCC bus I'm installing or should they have their own circuit (say from a separate 12v controller)?

I'll not be using DCC to control the points. (Too many points and not enough $).

2) If the latter, can I install the CDU on the common return?

Thanks, in advance for the replies.

Trevor

Bellingham, Washington, USA

[Donw]

Unless you plan to power the point motors via DCC the supplies must be separate. In that case the point motors should have their own common return with a switched feed to each coil. It then makes little difference whether the cdu is in the feed or return so. Point motor coils of the solenoid type are not polarity dependant. If however you use a diode matrix for route setting the polarity of the supply is important.

Don

[corax67]

I would recommend powering the CDU from its own dedicated power supply - a cheap cased transformer such as the Gaugemaster M1 or M4 - as it will ensure you get a positive throw every time.

[Crosland]

1) Can I power my Peco point motors from the DCC bus I'm installing or should they have their own circuit (say from a separate 12v controller)?

You can't power the point motors directly from DCC.

2) If the latter, can I install the CDU on the common return?

If the CDU recharges slowly enough then you could power it from the DCC bus, but I wouldn't. A sensible DCC track voltage is too low for switching Peco point motors.

 

Most CDUs are designed to go in the supply, not the return path.

 

Andrew Crosland

[Suzie]

If you want to run a CDU from the DCC track supply, there is a good design here you might like to look at:-

 

http://dccdiy.org.uk/cdu.html

 

A CDU will need to have fast diodes to work from the DCC track supply - most don't, and most solenoids will require a higher voltage than track voltage, so you will need a voltage doubling CDU for reliable operation.

 

The DCC track supply is a balanced supply so unsuitable for use with common return.

 

If you want to use a normal off-the-shelf CDU you really need to run it from a 1A 16V AC transformer and you need to keep the wiring completely seperate.

 

 

 

 

 

 

 

 

 

 

 

[Goathingham]

Thanks, All. The electric "fog" is lifting somewhat.

 

Cheers,

Trevor