Alright, I recently had the need to build a rectified AC/DC power supply. Yes, I mean rectified, not regulated. It won't be used to power sensitive projects.
I used Adafruit's current and volt meters to read out said values.
The problem I have is that when the current meter had it's (larger) sense leads plugged in to the circuit, and more specifically the positive of the two sense leads, a short circuit is produced. The current meter reads this short circuit as well. The bug is caused by the shared ground needed by the volt meter.
Attached below is a schematic of this power supply. The circuit relies on 0 - 60v AC input from a variac + step-down transformer. This splits off to a DPDT switch and bridge rectifier. After the rectifier comes some filtering and out it goes to the two other poles of the DPDT switch. The two common poles of the switch output to the output terminals on the case.
The current meter is only to sense current when the DC output is switched on, therefore, the sense leads tap out between the rectifier and switch. The volt meter also senses directly from the rectifier and it's filtering; it works just fine on both AC and DC.
Both meters are powered by an external 5v source which unfortunately shares the same ground as the rectifier.
Does anyone have any solutions to remedy this bug without losing features?
Edit: Updated schematic here: http://forums.adafruit.com/viewtopic.php?f=8&t=35267&p=175543#p175543