printer single supply becoming split supply?

[facundonu]

i have a couple of HP1410 multifunction printer power supply modules.
they deliver

---GND
---16v x 650mA
---32v x 1250mA

and i need 16v+16v for a low end preamplifier.

this PS is the clasical switching power supply.

can this modification be done for this purpose? will it work?



thanks a lot.

[rejithcv]

hi,

you can modify the power supply by rewinding the transformer which is not advisable. An easy way out may be using a linear regulator at the output stage of 32v. An Lm317 voltage regulator can be used. Since u need dual power supply one of the diode shuld we reversed, also the capacitor...

[paulb]

Originally posted by rejithcv
hi,

you can modify the power supply by rewinding the transformer which is not advisable. An easy way out may be using a linear regulator at the output stage of 32v. An Lm317 voltage regulator can be used. Since u need dual power supply one of the diode shuld we reversed, also the capacitor...

It's a switching supply, so I wouldn't advise you to do any rewinding. Also, reversing the diode isn't correct, you would have to reverse it and move it to the current GND output (making it a -16V output). The capacitor orientation will not need to be changed.

The diode on the 16V line will keep this output from being a proper ground, which needs to source and sink current. With the diode it can only source current. Imagine a resistor connected from the 32V to the 16V outputs. No current will flow because of the diodes.
Can you pull the AC from before the diodes and use an external bridge rectifier and capacitors instead? You will probably need more capacitance anyway to get a smooth supply.
Also, be careful about moving the ground. If you know for certain that it is isolated from the rest of the circuitry, then it should be okay.