nikisalli

modified 9 years ago

5A linear regulator

146

02:15:36

One day i go to the dump to find some big components like igbts transformers etc. I open a big 6kva inverter and find two big transistor-like big things. They're sgs80da020 big bjts (200V 120A). So, can i use them as linear regulators? I have also their big heatsinks (10*20cm)

-niki

published 9 years ago

hurz

9 years ago

12V 5A €5.99 on ebay ;-)

nikisalli

9 years ago

I want to use those big transistors

nikisalli

9 years ago

Can you draw me a circuit with variable current too?

hurz

9 years ago

Too? A free bjt AND a circuit for free???

hurz

9 years ago

I dont know, and I just guess you are well decorated with equipment. Maybe even better then me ;-)

nikisalli

9 years ago

I have a lot of extremely big components but you have a lot of experience in electronics that is much much more important then free 5500A thyristors!!!

nikisalli

9 years ago

(Yes i had 5500A 1300V thyristors for free)

nikisalli

9 years ago

(And 27 IGBTs)

nikisalli

9 years ago

(And hundreds of ICs and mosfets for free)

Addramyrz

9 years ago

Has this become a partslist for building a hurz?

nikisalli

9 years ago

For building hurz you need a bit of human, a bit of god, a lot of electronics experience and knowledge and a bit of irony and voila you made hurz ;-)

hurz

9 years ago

Gracias

nikisalli

9 years ago

So, how can i make this variable regulators?

hurz

9 years ago

First it needs a specification or requirement list

nikisalli

9 years ago

At least 5A regulation from 0 to 30v from 0A to 5A and ultra low ripple

nikisalli

9 years ago

With a 350VA transformer with 35Vdc output

hurz

9 years ago

So you like to build a 0-30V 5A power supply with ultra low voltage ripple. Can you write the requirement down?

nikisalli

9 years ago

I need it as a bench psu because my bench psu has too much ripple and interferences

hurz

9 years ago

How much is much?

nikisalli

9 years ago

It is not normal ripple it's like spikes of 500mV or 1V at a very high frequency

hurz

9 years ago

spikes with a constant frequency, or only from time to time?

nikisalli

9 years ago

Constant frequency

hurz

9 years ago

You have a big radio station close to your home, or its the bench supply itself which oscillates. Anyway, any news about SGS80?

nikisalli

9 years ago

It's the bench psu that uses china buck converters

nikisalli

9 years ago

I'm preparing the test now

hurz

9 years ago

Un pocito mas rapido por favor 😁

nikisalli

9 years ago

I've done the test

nikisalli

9 years ago

Why are you speaking that language?

nikisalli

9 years ago

Inputvoltage->collector voltage 1.36V->320mV 3.60V->1.92V 5.36V->3.52V 6.32V->4.40V 7.04V->5.12V 8.24V->6.32V 11.1V->9.12V 13.7V->10.3V

nikisalli

9 years ago

Schematic used: http://everycircuit.com/circuit/4568073139126272

hurz

9 years ago

Were is your 35VDC supply? And keep the base resistor higher, cuz your BJT does performs much better in hFE (current collector/current base) e.g. ~800Ohm.

hurz

9 years ago

BTW, if you dont mind, we should jump to the related bench supply circuit I published for further comments.

nikisalli

9 years ago

Ok👍

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