Help with unusual transformer

[UKMeterman]

Ok,
A better way forward would be a 12V PWM controller for the speed, fed from a safe 12V powersupply, just need to know how much current the motor takes when running. At a rough guess I would suggest giving this a try with the car battery as a power source https://www.amazon.co.uk/Motor-Control-Controller-Professional-Regulator/dp/B00H8JRXKG as a quick test. Please power the unit via some fuses and proper clips, short out a car battery and it will start a fire.

 

[Lucien Nunes]

Agreed, a PWM speed controller is the way forward. The many options on that Amazon page and many more that you get from googling '12V PWM controller' might all be OK but they are mostly unknowns.

The motor probably only consumes a couple of amps, maybe 5, I doubt very much it reaches 10A (does it get warm / hot?) If we say hypothetically that a 10A supply and speed controller will be ample (there's no harm in having them a bit over rated, they will run cooler and last longer) then as an example of units from a reputable source you could try this power supply:
STONTRONICS - PD-150-12 - Single Output Internal Enclosed SMPSU, 150W, 12V, 12.5A | CPC UK
feeding this speed controller:
KEMO ELECTRONIC - M171 - MODULE, PWM CONTROLLER, 10A | CPC UK

Mount the two in your chassis, connect mains in, 12V to controller and controller to motor and you're sorted. The motor may run slightly smoother and quieter too as there will no longer be the 100Hz ripple from the unsmoothed DC.

 

[Ironica]

Agreed, a PWM speed controller is the way forward. The many options on that Amazon page and many more that you get from googling '12V PWM controller' might all be OK but they are mostly unknowns.

The motor probably only consumes a couple of amps, maybe 5, I doubt very much it reaches 10A (does it get warm / hot?) If we say hypothetically that a 10A supply and speed controller will be ample (there's no harm in having them a bit over rated, they will run cooler and last longer) then as an example of units from a reputable source you could try this power supply:
STONTRONICS - PD-150-12 - Single Output Internal Enclosed SMPSU, 150W, 12V, 12.5A | CPC UK
feeding this speed controller:
KEMO ELECTRONIC - M171 - MODULE, PWM CONTROLLER, 10A | CPC UK

Mount the two in your chassis, connect mains in, 12V to controller and controller to motor and you're sorted. The motor may run slightly smoother and quieter too as there will no longer be the 100Hz ripple from the unsmoothed DC.

I had the most extraordinary turn of events yesterday. I work for Whipsnade Zoo steam railway and I went to London Zoo to assess the clearing of an old workshop they have. Amongst the lathes, milling machines and various machinery was a load of old electrical equipment, clearly not been used for many years, destined for the tip. There it sat. A dual tracking regulated power supply, made by maplin. This has solved my problem - I am able to fine adjust the running of the wiper motor so my engine can turn from very very slowly to fast speed. Quite an amazing find. I have downloaded a pic Thank you all very much for your replies, it was appreciated.

 

[Lucien Nunes]

That's a result, well spotted!

Looks like the output is running at max current in your pics. That's usually OK for a bench supply with variable current limiting, but if this model permits its outputs to be paralleled (some do, many don't) then that might be preferable to reduce stress. Give it lots of ventilation though, as its linear regulator dissipates heat that wasn't there in the old supply unit.

 

[UKMeterman]

Hi,
Filp the switch on the front to trackiing and use a pair of these http://www.maplin.co.uk/p/p600j-6a-silicon-rectifier-uk61r to common up the output of the power supply, thus the heat gets dumped in both sides. The side away from the band goes to the red side of the power supplies, the side with the band gets commoned up and then connect to your motor. Connect both negative supply terminals together and to your motor.
One question what would happen if there was a severe overspeed of the motor?

 

[Ironica]

Hi,
Filp the switch on the front to trackiing and use a pair of these http://www.maplin.co.uk/p/p600j-6a-silicon-rectifier-uk61r to common up the output of the power supply, thus the heat gets dumped in both sides. The side away from the band goes to the red side of the power supplies, the side with the band gets commoned up and then connect to your motor. Connect both negative supply terminals together and to your motor.
One question what would happen if there was a severe overspeed of the motor?

now that's interesting. The unit was found with 3 leads - one red and two black. Just thought one red lead was missing. I wonder if this has been done before? As for running it too fast the tension of the belt on the flywheel means even at full power it will not throw the motion over excessively.

Thanks