Accessory Controller

[lickeyjunction]

Hi all

I am looking for an appropriate acessory transformer, to power 16 PL-10 & PL-11 point motors.

There may be more accessories to add, but for now...

GM M1 is recommended. Any other alternatives and why please?

I would rather pay for a purpose built unit, than play with pc power leads...electrics are not by strong point.

Running toggle DC points, as I want to control independently.

Thanks

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[RFS]

The output of the GM-1 is only 1A I believe, which won't be enough to power the PL-10 solenoids unless you also use a CDU (capacitor discharge unit). You really need at least 3A output for these motors to ensure reliable operation.

[Flashbang]

Hi.
The Gaugemaster cased GMC-M1 is a dual output ready built power supply offering 2 x 16volt AC outputs each rated at 1.0Amp. GM price is listed as being £62.50 - Expensive! It can, like most GM products, be obtained cheaper from other GM retailers. One of its 16v AC outputs is capable of operating one solinoid point motor such as one Peco / Hornby/ GM solinoid motor, when these are wired with suitable sized wire. Here my recommendation is 16/0.2mm equipment wire be used throughout or even use a larger wire size.

Where two (or more) solinoid motors are to move together from one switch or lever then the use of a CDU (Capacitor Discharge Unit) is highly recommended. Usually only one CDU is needed for the whole layout and it is connected onto one of the 16v AC outputs of the M1 and then the CDUs two output connections are feed - Positive to all levers or switches etc and the Negative runs out to the layout and connects to all motor returns. Use of 16/0.2mm wire minimum is still recommended.

To note, Gaugemaster also produce a 16v AC plug-in style power supply which is their GMC-WM3 (their retail price £21.00) https://www.gaugemasterretail.com/magen ... c-wm3.html. This will, like the M! will operate one solinoid motor or several motors at the same time with a CDU.

I highly recommend the use of a CDU, regardless of how many solinoid motors are to be moved with a single switch or lever etc operation. A CDU stores energy provided by the power supply and when the switch/lever etc is operated it releases this stored energy as a "Beefy" pulse of power to the solinoid(s). Next it helps prevent solinoid motor coil burn out should a switch or lever remain in the On position for too long as once discharged it cannot recharge until all operating levers or switches are in their Off positions, Finally, using a CDU means the power supply feeding the CDU and motors need not be so large in current output, as its the CDUs capacitors that store the energy. A CDU feed with around 16v AC will provide 22.4volts DC on its output. CDUs are sold by many suppliers, so their is a wide choice, prices range from around £6 up. Typical example https://www.ebay.co.uk/itm/400583931383 ... SwrbtaiaHo

[Suzie]

That is a lot of money for something that is not ideal for the job.

Get a 4A 24V DC switchmode power supply, and a CDU, and you will have an ideal solution that will be:-

- Lighter (transformers are heavy!)
- More efficient (transformers are lossy by modern standards.)
- More powerful (24V will shift the motors much better than 16V)
- Safer (no possibility of motor burnout with a CDU.)
- More reliable (results will be consistent regardless of the variability of mains voltage.)

Wiring the PSU to the CDU is dead easy, so no need to be frightened of it. Things have moved on since the 1960s when the transformer might have been an OK solution for solenoid point motors, but now it is just an expensive way of doing the job in a mediocre way. The GM M1 will only be recommended by a supplier that does not offer a better alternative. It has its uses, but a power supply for 4A solenoid motors is not one.

[pete12345]

Seconded. Just about any common laptop PC power supply, coupled to a CDU, would do the job for a lot less than the Gaugemaster offering- which is expensive for a very basic transformer. You probably have one laying around in a drawer somewhere.

[Flashbang]

Note Not all laptop PSU will do! Some have and need a third or fourth connection to monitor the laptops battery! So a little care is needed when choosing one! Additionally, the CDU must have an Input voltage rating above the PSU output voltage.

BTW.... You DO NOT necessarily need a 4.0Amp PSU when a CDU is used. In fact anything between 3/4 Amp to 2.0Amp is more than ample when charging a CDU. However, many 19 to 24volt Laptop chargers are rated between 3.5 and 5Amp output.

If using a former Laptop PSU you have two options.... A) Cut the moulded low voltage plug off, strip the wires - hopefully only finding two wires! and terminate them onto the CDU input terminals. Ensuring positive is to the CDUs input positive as not all CDUs have a full wave bridge rectifier immediately after the input terminals. Note: Doesn't matter which way around they are when using AC.
Or B) Obtain an in-line Female matching DC socket. Example Typical 2.1mm example Here you will have to find out the size of the moulded DC plug on the PSU. Frequently either 2.1mm or 2.5mm, but they can at times be other sizes! Then from the socket two wires connect to the CDU, again ensuring correct polarity on the CDU input.

[Bufferstop]

I'm not saying they don't exist but I have yet to see a laptop charger that has anything other than a single coaxial connector, the "clever charging bits" being the first thing connected to the laptops input socket. I have a number of stand alone hard drives which have a four pin connector with 5v and 12v lines. These can be useful for accessories other than point motors, I have a boxful of "power bricks" and "wall warts" which I spent several hours going through putting on Dymo labels with their voltage, the printing on the rating label is often far to small and poorly defined to read without a magnifier and good lighting.

[Roger (RJ)]

I'm not saying they don't exist but I have yet to see a laptop charger that has anything other than a single coaxial connector, the "clever charging bits" being the first thing connected to the laptops input socket. I have a number of stand alone hard drives which have a four pin connector with 5v and 12v lines. These can be useful for accessories other than point motors, I have a boxful of "power bricks" and "wall warts" which I spent several hours going through putting on Dymo labels with their voltage, the printing on the rating label is often far to small and poorly defined to read without a magnifier and good lighting.

I think it was an old Dell laptop that used a 3 or 4 wire charger.

[Flashbang]

I'm not saying they don't exist but I have yet to see a laptop charger that has anything other than a single coaxial connector, the "clever charging bits" being the first thing connected to the laptops input socket. <SNIP>

I agree. The vast majority of laptop style power supply units (PSUs) have two wires and they are normally terminated into a male DC Barrel connection of various sizes.
However, there are three (or four?) wire ones around and I have been caught out by these! In fact, I recommend a few years ago on this very forum to a user to obtain an ex laptop PSU for their point power supply and got short shift from them when it wouldn't work! .. Yes, it was a multi wire PSU they had purchased new. Hence the warning.
There are also rectangular moulded laptop plus also USB C type available, The rectangular type may prove a problem obtaining an in-line connector to match if cutting off the moulded connector is not a thing wished to be undertaken. I assume these are all two wire feeding but I haven't one to look at?

Example of both 3 and 4 wire laptop power connector tips....

Tips.JPG (23.05 KiB) Viewed 1050 times

[Suzie]

Some CDUs take around 2A initial inrush current when fed with 24V DC, so when using a switchmode PSU to power a CDU it is important that the initial surge current does not exceed the PSUs rated current or it is likely to shut down when you first turn it on, and some (but not all) switchmode PSUs have to be powered down and left for a while to reset if overloaded which can catch you out. If you have a small one it can easily be tried, and if it works it will be fine, but if buying one something in the 3A-5A range is a sensible choice to make sure that you will have something that is working well within its design range.