Split potential power supply for Fulgarex point motors

[CKPR]

I'm looking to convert control of my Fulgarex point motors from 12v using DPDT switches to a seemingly simpler system using a +12v / -12v split potential supply as per CLAG guidance [http://www.clag.org.uk/fulgurex.html ]. My queries are (a) given that CLAG advice that the Fulgarex motors are 'rather fierce' when used within their 10-14v range,  should I use a power supply rated at +9v / -9v rather than +12v/-12v and (b) what is a safe current to use ? I'm aware that the Fulgarex motors are rated at 200mA but the split potential power supplies I've been looking at all seem to be rated much higher than than this e.g. 1000mA.

 

All and any advice on these matters would be most welcome.

Edited November 5, 2020 by CKPR

[melmerby]

The rating of the power supply will be fine as long as it's rated at at least the current consumption of the motors.

The current consumption at 9v should be less than at 12v

If they reliably work at 9v all will be fine. Can you try them at 9V before investing in a new supply?

 

(Don't go to the other extreme and use an e.g. 10 Amp power supply)

Edited November 5, 2020 by melmerby

[Dagworth]

If the motor is rated at 200ma that is all it will take no matter how capable the supply. You could run the motors from a car battery with no problems, whereas to start a car may require 300 amps or more from the battery.

 

 

Andi

[Crosland]

21 minutes ago, Dagworth said:

If the motor is rated at 200ma that is all it will take no matter how capable the supply. You could run the motors from a car battery with no problems, whereas to start a car may require 300 amps or more from the battery.

 

With the thin wiring you could use for these motors at 200mA you wouldn't even need a fuse 

 

(extra smiley for the avoidance of doubt)

[kevinlms]

1 hour ago, melmerby said:

The rating of the power supply will be fine as long as it's rated at at least the current consumption of the motors.

The current consumption at 9v should be less than at 12v

If they reliably work at 9v all will be fine. Can you try them at 9V before investing in a new supply?

 

(Don't go to the other extreme and use an e.g. 10 Amp power supply)

The biggest problem with using a large power supply (such as 10 Amp), is that if something goes wrong - a short, then the power supply, isn't going to give up easily! It will keep on pumping current into a mere toy, like a Tri-ang point motor, until the smell of burnt plastic sealed inside escapes! It needs something to limit the current.

[kevinlms]

51 minutes ago, Crosland said:

 

With the thin wiring you could use for these motors at 200mA you wouldn't even need a fuse 

 

(extra smiley for the avoidance of doubt)

There is always these fuses!

 

http://www.funnyism.com/i/funnypics/guideforfuses

[CKPR]

Thanks for the replies and information.

[ScRSG]

Have a look at this useful board - 12v Split-Supply  https://www.dccconcepts.com/product/12v-split-supply-pcb-only/ Use basic 1 amp power supplies. We have used these to fire Cobalts and Fulgurex with no apparent problem.

 

(No connection)