EEVblog Electronics Community Forum

Electronics => Repair => Topic started by: Andbro on July 23, 2019, 11:17:08 am

Title: Power Supply repair need help
Post by: Andbro on July 23, 2019, 11:17:08 am

Hi,

I have an old power supply built with Lm723 and 2N3055. The transformer is dead.
What's the best solution for fix

1- Replace the transformer by a new?

2- Replace the transformer by quality SMPS like Mean Well or CUI?

Thanks

Title: Re: Power Supply repair need help
Post by: firewalker on July 23, 2019, 12:20:32 pm

Will the noise of the SMPS be an issue? What is the price difference?

Alexander.

Title: Re: Power Supply repair need help
Post by: PKTKS on July 23, 2019, 12:58:41 pm

Well  i am aware that LM723 can implement even switch mode..

But 99.99%  LM723 topology is LINEAR.

Using a 2N3055 BINGO! you have a LINEAR SeriesPass
usually  ranging from 2 to 20V - in rare cases 0-22

You can make a new winding on your old TRAFO ..
But depending on the price of any equivalent...
I would not.

Here i can find a brand new one almost the cost of rewinding

Paul