No everything is connected, base, collector, emitter .

Are you really, really sure?
Measure the resistance between LM317 output and the base of one the 2N3055.

 

Are you really, really sure?
Measure the resistance between LM317 output and the base of one the 2N3055.

Everything is " physically connected " , but when trying to measure, LM317 Output resistance / transistor base with range 400, 40K, 4M : OL so not connected !!!!!!!!!!!!

 

Il est temps de célébrer. Je vous souhaite un hereux 14 Juillet!

 

Merci, ça fait plaisir un petit message en français.
Nice, can't say it in italian.

 

Only check Vbe, Vce, Vbc with diode check function of dmm, all seems correct. Sufficient to be sure transistors are ok?

 

Sufficient to be sure transistors are ok?

If you measure very high resistance between LM317 output and the base(s) of the 2N3055 then they are not connected even if they look like they are. Check that connection very carefully.

That slowly rising output voltage is exactly what I would expect if that connection was missing. Concentrate on that.

 

If you measure very high resistance between LM317 output and the base(s) of the 2N3055 then they are not connected even if they look like they are. Check that connection very carefully.

That slowly rising output voltage is exactly what I would expect if that connection was missing. Concentrate on that.

Hi Albert,

You are absolutely right; in fact one solder seemed good but in fact, was forgotten on pad....
Checked with dmm, soldered it and works fine: 13.6V display output.

Next step, remove 2W 2.2 KOhm resistors and replace it by precise potentiometer, to get psu fully functionnal.

Thanks a lot for your patience Albert, and replies.

Thanks a lot also for all members of this forum, and augustin for his french message.

Sympa augustin, ton joyeux 14 Juillet.

jm

 

Excellent
But do check the current sharing before you load it fully.