How can I build tracking bench supply from SMPS

G

Graygem

Member

• Mar 4, 2014

• #1

Hello,
I have a 800 watt ±70V SMPS and was wondering how hard it would be to build a dual tracking bench power supply out of it.
Can anyone help?
Thank you

 

ronsimpson

Well-Known Member

Most Helpful Member

• Mar 4, 2014

• #2

+/- 70V 1A supply.
How is it not a bench supply?
What do you want it to do?
Do you want meters? V and A?

 

G

Graygem

Member

• Mar 4, 2014

• #3

It is just a bare smps. I need an adjustable 0 to ±70V. And yes, I would like the readout of voltage and current.

 

ronsimpson

Well-Known Member

Most Helpful Member

• Mar 4, 2014

• #4

I would get some of these.


Do you have a schematic for your supply?
One idea is to get the smps to go 0 to 70 volts. It probably will not be easy.
Idea 2 is to add a linear or smps on the output that takes the 70v and makes 0 to 65 volts.

 

crutschow

Well-Known Member

Most Helpful Member

• Mar 4, 2014

• #5

What is the SMPS you have?

 

dr pepper

Well-Known Member

Most Helpful Member

• Mar 4, 2014

• #6

Do you have a schematic, or at least the type of controller chip it uses if it has one.

 

4pyros

Well-Known Member

Most Helpful Member

• Mar 4, 2014

• #7

Ya lets hack a +/-70 volt SMPS!

 

dr pepper

Well-Known Member

Most Helpful Member

• Mar 4, 2014

• #8

Roughly translated - only do something like this if your reasonably competant.

 

G

Graygem

Member

• Mar 5, 2014

• #9

The SMPS is actually a SMPS800RE from Connexelectronic. It is their ±72v version with a ±15v auxilary.

 

ronsimpson

Well-Known Member

Most Helpful Member

• Mar 5, 2014

• #10

Most smps will not be happy changing the error amplifier to make it go down to 5 volts.
I think you should make a buck converter to take the 72 volts down to (0 to 65V)
Picture:

 

dr pepper

Well-Known Member

Most Helpful Member

• Mar 5, 2014

• #11

If you went from 72v to 5v you wouldnt get anything like the 800 watts, for that you'd have to do some drastic stuff like rewind the inductor and replace the recitifiers/output inductors and beef up the tracks.
Rons suggestion is better.

 

G

Graygem

Member

• Mar 6, 2014

• #12

Here I thought it would be easy. My thought was to build a circuit that would take the output from the smps and adjust that, instead of modifying the smps itself.