Model Railway Forum

This will do all you need
https://www.ebay.co.uk/itm/BLOCKsignall ... SwrbtaiaHo
If you don't want to use eBay then go to the manufacturer direct at http://www.blocksignalling.co.uk/index. ... du2c-cdu4c Same person at both places

Thank you Brian that is most helpful.

I have a redundant laptop charger, output 22.2v 500mA, can I use this to operate my points through the mentioned CDU?

John

Nine Elms wrote: ↑Tue Feb 23, 2021 11:33 am Thank you Brian that is most helpful.

I have a redundant laptop charger, output 22.2v 500mA, can I use this to operate my points through the mentioned CDU?

John

Hi John
The voltage is OK and at 500ma it may take a second longer to reach a fully recharged state of the CDU. Are you sure its 500ma (1/2 Amp)? As that's very low for a laptop power supply. Normally they have a much larger current output, frequently of 3.5 to 5.0Amp (3500ma to 5000ma)

There is no stress on a power supply when using a CDU, as its only the capacitors that are changed by the power source. They store and release the beefy pulse of power and once the operating lever or switch is restored to the Off position (point motor disconnected) then they recharge again. Stress on a power supply would be when that source is used as a direct power supply without a CDU. In that case your PSU is not suitable as the maximum current at 500ma (1/2Amp) is too low!

From the details of the CDU I linked to above..
The CDU inputs can be connected to any DC power supply up to 35V or AC power supply up to 24V.
Do not exceed these input voltages to avoid damage.

The minimum supply voltage is 12V AC or 15V DC, as below this level the CDU will no longer improve the action of the points.

Brian.

The unit just says "charger" and it is 500mA, so I will keep it in the drawer for now and look for a suitable supply.

Thank you.

John

It will be fine with a CDU
Without a CDU you need a larger current output supply.

If you want to go with a different supply just for powering a CDU then the Gaugemaster WM1 is ideal or even an old train set controller that have an auxiliary 16v AC output.

I checked-out the Gaugemaster 20 point motors and am not that impressed. They are designed to work in either N or OO gauge, but aren’t particularly compact, and they seem pretty flimsy. I’ll be using Hornby motors when I start sorting out my points.