Power supply for LPL 4500

**dileep prakash** · 9-Oct-2001, 03:04

Folks: I have a LPL 4500II enlarger from the US which is 110 volts. In India we get 220 volts. I need to adapt the power supply. Would anyone have a circuit diagram of the "Saunders LPL 4500 DMA Regulated Power Supply". It would help me a great de al. Thanks Dileep

**Charlie Stracl** · 9-Oct-2001, 13:46

I don't have a circuit diagram, but a step-up transformer is not very expensive, so that's an alternative.

Saunders or LPL might provide the diagram to you if you ask.

Charlie

**dileep prakash** · 10-Oct-2001, 04:18

I have built a 220 to 110 step down transformer and adapted my 220 volt timer also. But the output I am getting from the Power Supply is 110 volt for the lamp - this should be 82 volts since the lamp is a 82 volt 200 watt. Maybe I've joined some wires wrongly.

Saunders says it cannot help since they dont make the Supply themselves but outsource. I really dont know what to do.

**Colin Benson** · 10-Oct-2001, 18:15

Hi Dileep,

you might try mailing Robert White (sales@robertwhite.co.uk) in the UK since they certainly sell the enlarger. Here 220V is the norm (as I'm sure you already know.) I too have a Saunders enlarger purchased while I lived in the USA. Once I have somewhere to erect it I intend to go through exactly the course I've just recommended to you so please let us know how you get along. For what its worth, I have not dealt with Robert White's myself but they seem to have a good reputation in this and other fora.

Best of luck

c

**Phil Brammer** · 11-Oct-2001, 03:59

I dont know much about your enlarger but i think that the lamp would operate off 82V as the if is was designed to run off 110V there would be no way the regulator could compensate for any drop in power from the power piont below 110V. If you cannot get a circuit diagram for your enlarger try using a variac instead of a stepdown transformer. You can adjust the output voltage. There will still be variences though as it will not be regulated, but the variations will be reduced as a function of the stepdown the variac provides (just like a transformer). You may have to keep an eye on the voltage at the lamp, hopefully youre exposures dont last for too long as you wont be able to adjsut while your burning and doging!!

**dileep prakash** · 11-Oct-2001, 13:14

Folks:

It seems that if the output from the Power Supply is tested with a voltmeter it shows 110v. But when a 82v lamp is put and switched on it comes down to 82. While the supply for the fan remains at 110v. The electrician I went to showed me this using an ordinary bulb. He says that AC circuits work this way when they are thru a regulator (which is built into the power supply). So I hope my problem is solved. But I am still going to test it out on another enlarger lamp to be doubly sure before I put my LPL to use.

The other issue was the timer which is also Indian and 220v. This he sorted out by changing the "relay" (?) and it seems to work fine. I didnt understand how he did it but now the timer takes its main input from a regular 220v supply and also has a second input of 110v from the Saunders LPL supply and then an output back to the LPL supply.

Sounds complicated to me. But I've asked the gent to make me a circuit diag for the timer change which I am willing to pass on to anyone who needs it.

Thanks Dileep