Masters2504

Thanks audioguru on the answer :). Yes you are right, my mistake, no one recommended the A version of the opamp. I will use this MC34071PG opamp that I have. Thanks for the suggestion to use two 2N3055 transistor to share the heat. I will use that modification.

Hello to all, I started building this power supply using the project on this web page http://diyfan.blogspot.com.br/2012/02/adjustable-lab-power-supply.html, which is basically the same project at this listed here. But I have a couple of questions. First, from the posts I have read here, I saw that the recommendation is to use the MC34071APG IC. I managed to get a hold of MC34071PG IC (difference between these two is the lower input offset voltage of the MC34071APG). My question is, can I use this MC34071PG IC for this project? Secondly, the transformer used in the project has one primary and two secondary windings, one secondary providing 30VAC at 4Amps, but I have the problem in determining the characteristic on the second secondary winding (I guess that I need at least 9VAC for providing the power to the temperature controlled fan and panel ammeter)? Thanks in advance :)