0-50V 2A Bench Power Supply.

[mastrila]

Hey everyboby,
I have a 36V 6A transformer that could be used to built this power supply. Although it likely will not support a full 50V output, it will greatly expand the range of my battery chargers (based on the MAX 712/713).
A few questions:
1) The article indicates that P1 and P2 are used to control voltage
and current respectively.
What is P3 for? How it needs to be adjusted to achieve its
pupose?

2) What would be the best place to put a green LED to show
that power is on. I think that in parallel with C5 ( mine is a
9000 mF 100V) with a suitable resistor would be fine.
Is there a way to show (with a red LED) that the set current
limit has been reached?

3) Finally, if i decide not to take advantage of the current limiting
function, which is not useful for my purpose, can P2 and P3
be eliminated? How would this be achieved?

Thank you in advance,
Mastrila.???

 

[ante1]

Mastrila,

If you don't know it: the maximum peak voltage for the MAX712 is 45Volts and you should stay well below this.

 

[mastrila]

Ante,
yes you can. MAXIM has recently posted a modified circuit that
allows use of a higher voltage.
Anyway, that is not my question.

Mastrila.

 

[ante1]

Mastrila,

1. With P1 you can control the voltage linearly, with P2, which is a preset you adjust the maximum current (2A) and P3 is where you adjust the current normally.

2. Parallel with C5 will be fine; I assume you mean 9000 uF (micro) not 9000 mF (mili)?

I don

 

[mastrila]

Ante,
thank you for the helpful advise.
Yes, I do mean micfoF.
I have read your note of caution with interest. I will give it a try anyway since I already have the most expensive component (viz. the transformer) and most of the others. If things do not work out, i can always revert to the original schematics (30V, 1A).
It will be a nice way to pass a cold winter evening, or two.
One more question, can I get rid of P2 altogether? What R value do you suggest for a 2A output?
I will let you know how things turn out.
Best regards,
Mastrila.

 

[ante1]

Mastrila,

There isn

 

[mastrila]

Ante,
thanks again for your advise.

What do you mean by "calibration". I will need some (a lot of, in fact) guidance on how to do it.
Once that is done (hopefully without blowing anything up), can I measure R off the pot and replace it with a fixed resistor?
Can P2 be a 10-20 turn pot instead of a bulky potentiometer?

I will only use this PS in its upper range (for anything lower than 30V i have a very good quality 0-30V 0-2.5A switching PS). Therefore, heat dissipation should not be a big issue. In any event, i do have several heatsinks, some with a fan, that I can choose from.

I have seen the 10-Mosfet 0-60V 0-5A PS you have recmmended to another member. It is quite impressive but too complicated for me, yet. Maybe some day I will give it a try.

I really appreciate your patience and value your advice,

Mastrila.

 

[ante1]

Mastrila,

The P2 preset pot can be any type of pot you prefer, multiturn or not it