Regulated Power Supply Circuit design

[schmitt trigger]

For a hobbyist, building equipment is a learning experience, also an imperative. You build a limited LM317/LM337 linear supply, learning a lot (morale boost), and move on to use it for other experiments. You become aware of its limitations, and learn more. Then you decide to build a better supply, and you're ready for it.

That is my personal experience also. Although in my case I started with the LM723.
The good thing about the 723 is that the essential regulated PSU building blocks are all exposed and there, one can learn about a basic architecture, which one can improve later.

And the good thing about building your own power supply is: you are no longer at the mercy of batteries!! One can really start experimenting with stuff, without a concern that the batteries are flat.

[techguru]

hi to all,

            Can anybody help me in constructing Circuit using LM723 IC where i could adjust current as well.I Request  to Reply to this if you could help me out in getting a solution. Thanks to all of you.... Good day...

[hermit]

This forum, and indeed the  internet at large, is littered with examples of these circuits.  At some point you need to show a little initiative and do some of the work.

[techguru]

HI hermit,

              I have tried the following circuit which i found while browsing. but non of them is usefull for adjustable current regulation. for example this circuit is using 500ohm variable resistor for current control but i found 3 of my regulator IC got breakbown. It may be the voltage between pin2 and pin3 may exceeded 5V or voltage across 500 potentiometer may be greater the breakdown voltage of base emitter junction. What may be the reason?

                  There is no guarantee for output when we copy circuit from google.

I know to get current limitation function for IC either by Foldback Regulation or normal current limitation to protect series pass transistor from LM723 Data sheets.

                        My question is how to control current at output by selecting appropriate potentiometer between pin2 and pin3?

[hugo]

Why don't you try this one:

http://www.ve2ums.ca/chasse/Serge/Atelier/Projets/Membres/VE2EMM/alimentation_ang.htm

It works fine for me.

[oldway]

You could use the schematics of the Philips PE1542 bench power supply.....it was a very good power supply, very reliable.

But it only need one 24V secondary.....
For two units, you need two separate 24V secundaries.

You can download the service manual with schematics here:
https://elektrotanya.com/philips_pe1542_service_manual.zip/download.html
Wait processing became Get manual....

[techguru]

Hi oldway,

    I couldn't understand the technique to analyse the circuit.At what point I should start and how to analyse the circuit. Which electronics book such schematic and analysis.

what will happen if i place two Iron core transformer close to each other? How to place them? Will coupling coefficient and Flux created on one coil will affect each other?

[IanB]

what will happen if i place two Iron core transformer close to each other?

Nothing.

How to place them?

According to wiring layout and mechanical security.

Will coupling coefficient and Flux created on one coil will affect each other?

No. Transformers are designed to keep the flux inside the core, not outside. If the flux were outside the transformer would be inefficient.

[techguru]

Hi to all,
Good morning today , I was working in my laboratory for circuits lab. I connect class A amplifier and switched on my power supply. The supply gave a hum when I switched my mains power. What does it say the class A amplifier overload the regulated power supply or there is short in breadboard. Else the RPS is poorly designed? What are the technique to be used reduce hum?

[techguru]

Good morning to all,

          From previous two replies, I have got the circuit for current control but I don't know to explain how it works. When some thing go wrong, then I may not know to troubleshoot the circuit.

So i want to work with opamp based current control , then i will add this current control circuit to voltage regulator. Hence I want good circuit book to understand theory behind the operation of circuit.. Thank you all .. good day..

[techguru]

Dear all,
            I want to design regulated power supply for my lab which should be programmable for both voltage and current. I bought a transformer of 24V@ 5Ampere centre tap.How much DC Current i can take from the Regulator. What decides the current.give me some reference for this .Thank you all gentle men...

[techguru]

Good evening all,
                 Now I am interested in constructing variable current limiting circuit. I constructed a simple circuit using LM723 IC. Please help me construct the same using operational amplifier , so that I could include with voltage regulator.

[tooki]

Do your own homework! There are tons of existing discussions here and elsewhere on such things, if you just do a little legwork yourself. 

[Cliff Matthews]

Do your own homework! There are tons of existing discussions here and elsewhere on such things, if you just do a little legwork yourself.

After a week of only his posts, I think Guru got the message...  Three cheers for self moderating forums!

[techguru]

Here is the circuit i am working,

                                           Now i want adjust the current limiting resistor to adjust my current but the problem i cannot have variable resistance of 0.3 ohm(potentiometer). how to implement the resistor to adjust the current ? help me in this regard..

[Cliff Matthews]

Seriously, you have beat the p#ss out of this thread. It's time to start another thread and be more specific, OK?

[techguru]

Cant Get you Cliff!!!!