Need Help With Power Supply

[jeffg]

Hi guys i bought a power supply on ebay 115v input 24.5v 18a output regulated continous. My 1st question is what is regulated and unregulated My 2nd question is what does continous mean? I am adding a pic. and schematic that came with it. Dose anyone know if i can convert this supply to 48v? It looks like the transformer inside is 50v but i am not sure i really dont know how to read schematics. The steppers i have are 60mm x 85mm 4 wire bipolar 2.5v 4.4a Is this power supply good for the steppers i have i will need to run 3 of them?

[NC Cams]

The voltage to the LEFT of the Q1 (2N2147) is UNREGULATED. the voltage immediately to the RIGHT of the same Q1 is REGULATED.

The unregulated voltage is HIGHER than the required output and the regulator circuit senses the voltage and turns the Q1 transistor on or off to regulate the voltage at the liste 24.9VDC

[NC Cams]

The voltage to the LEFT of the Q1 (2N2147) is UNREGULATED. the voltage immediately to the RIGHT of the same Q1 is REGULATED via the circuitry in the regulator section of the P/S.

The unregulated voltage is HIGHER than the required output and the regulator circuit senses the voltage and turns the Q1 transistor on or off to regulate the voltage at the liste 24.9VDC

For a stepper, the use of a regulated P/S is not needed/required and can actually be a hinderance as a result of induced feedback voltage spikes from the stepper.

[Al_The_Man]

You have several secondary connection options if you went unregulated, just a bridge off of any of the combinations of the secondary, it does not seem to show what is across 9 to 13, you need to measure the actual AC on each winding and see what the variations are.
Al.

[martinw]

Originally Posted by NC Cams For a stepper, the use of a regulated P/S is not needed/required and can actually be a hinderance as a result of induced feedback voltage spikes from the stepper.

Dear NC,

I absolutely agree. Voltage spikes from an inductive load may destroy the output semi-conductors of a regulated PSU. IMHO, transformer,rectifier and smoothing capacitor. It is simple, and there is little to go wrong. It does though!


Best wishes

Martin

[jeffg]

Thanks guys i think i understand what you are saying i opened the supply up and tested volts at the top of the capacitor i have 38v so just get rid of the regulating board and get power from the top of either capacitor? to power the stepper drives then i wouid need a plug type 5v transformer for the 5v side of the drives? And at 38v how would i test how many amps i am getting at 38v? Heres some more pics.

[Al_The_Man]

Originally Posted by jeffg And at 38v how would i test how many amps i am getting at 38v? .

You would need to know the VA of the transformer, Going by the physical size I would guess that the VA is ample for what you need.
Al.

[martinw]

Originally Posted by Al_The_Man You would need to know the VA of the transformer, Al.

The VA rating may be on the label of the transformer. Alternatively, pick up the phone and call the PSU manufacturers. I think their website is

www.newmartelecom.com

Regards

Martin