How do you make a current limiting knob for power supplies?

[frank_p]

http://www.eserviceinfo.com/downloadsm/35282/Mastech_3003,%203020.html

I passed many hours today on that schematic and I think it is rewarding.
I will pass more time on it again.
Proabably that fooling around with this circuit will be a "long term" project.
I was going to type a ton of questions, but as I type it I understand "some bits as I go", so I guess I have to continue on asking myself questions...

[frank_p]

130$  How can they sell that at that price 
http://www.electronickits.com/kit/complete/powe/Mastech%20HY%203005D%20Bench%20DC%20Power%20Supply.htm 

[frank_p]

I got lazy because I saw something even cheaper:
But I still have some experiments on my breadboards...

I bought this today for cheap:
Kikusui PWC 0620



These are their old models.
This one is triple output with dual tracking side (0-20V; 1A) and a single adjustable other side (0-6V; 3A);
Both sides have current limiting knobs but one is dual.

The used one from this brand can be bargained for nothing.


I even saw some single output with current limiting (with more current and voltage capabilities)  going for 10$.
Those would be great for very low budjet acquisition, they are cheaper than the transformer that is in there  .

The (mechanical) construction is even more rugged for less money than the new ones.

A bit of principle of power supply on  their site:
http://www.kikusui.co.jp/knowledgeplaza/powersupply2/powersupply2-1.html

One was sold for 35$ on E-bay...
http://cgi.ebay.com/KIKUSUI-0-TO-20-VOLT-0-TO-3-AMP-REG-DC-POWER-SUPPLY_W0QQitemZ270237295536QQihZ017QQcategoryZ58288QQcmdZViewItem

I don't know their reputation but keep an eye on that brand if you want one for cheap.

[Nasse]

Sweet lookin machine. I have old repair shop lab supply. I´t heavy and large, and sometimes it blows the big fuse in the wall when powering up,. The tech who gave it to me could not repair it so I have not bothered,  no problemo...s yet. But back to the topic, I think I saw nice small circuit diagram in Elektor Summer issue, I believe. You could download it cheap. And because there are so few magazines survived I think it would be nasty to spread the schems illegally...

[frank_p]

I think I saw nice small circuit diagram in Elektor Summer issue, I believe. You could download it cheap.

I might get a look at it at the library.  It's the issue from this year ?

[Nasse]

Yes, July/August issue, worth downloading or buying, about 100 small circuits

[frank_p]

Ok thanks,
I am going to see it at the store.