Convert 0-30V 3A PSU to 5A or more

[audioguru]

Hi Boco,
Welcome to our forum.
We have another long thread about our 0V-30V/3A power supply project. It had problems so I suggested a few improvements to fix it. I have posed my suggested parts list many times in the other thread.

5A is not much more than 3A so the improved circuit is the same except a higher current power transformer is used, a 3rd 2N3055 output transistor with an emitter resistor is added to help share the extra heat and R7 is changed to 2.7 ohms/10W.

[bugmenot]

Ops do you mean 0,27R 10W? Hehehe
Audioguru can I use 2 0,47R 10W in paralel for R7? Its the more aproximately value I found (for the 5A or more layout).

[audioguru]

Ops do you mean 0,27R 10W? Hehehe
Audioguru can I use 2 0,47R 10W in paralel for R7? Its the more aproximately value I found (for the 5A or more layout).

Two 0.47 ohms resistors each will dissipate 2.9W (2.5A each) so a 5W size will be fine.
The voltage across them is only 1.175V at 2.5A each so the value of R18 will need to be increased or the max current will be much higher than 5A.

[ZeroKool]

I guess I came late to the show. I have finally read every comments for this 0-30V @0-5A modidification and is ready to build my own. Does anyone have a final revision of the schematic and PCB layout or know where I can find it? Please send it to me.

Thank so much
ZeroKool

[fuzhouled]

Good one learn a lesson