Power Supply drawing more amperage with PCB than breadboard

[Matt_Welker]

Hi, first timer here, I hope Projects is the right place.

I created a dual power supply with a LT1054. On the breadboard it draws ~50mA and outputs +9V and -9V. That’s what I want.

Built on a PCB it draws over 140mA and outputs +6V and -1V. I used 0.400mm (15.75mil) traces for the power (too big?) and I use a hatched copper fill for GND on the back layer. Could that be the issue?

Thanks,
Matt

[3Dogs]

No, that doesn’t sound possible.
It sounds like a layout issue on the PCB. Or, maybe capacitors / diodes in backwards.

[Matt_Welker]

Hey, thanks for the fast reply! I’ll check all the caps/diodes and see how it goes. Cheers!

[Matt_Welker]

@3Dogs you’re a genius.

C5 and D4 were both flipped.

Datasheet to breadboard. Check
Breadboard to hand drawn schematic. Check.
Hand drawn to Schematic Editor…

Thanks a ton!

[3Dogs]

I’m not a genius, I’ve just been doing this for a really long time…

Glad I could help.

[retiredfeline]

There’s your problem. Start with the schematic editor and you’ll have a reference for the breadboard, and then an easy transition to a PCB.

[Matt_Welker]

Good tip @retiredfeline . This was my first PCB, still ironing out my workflow!
Cheers, Matt