Category: Schematic

DC Power Feedback Signal Generator

I developed this circuit to gather average voltage and current data for a switched DC load and serve them as 5Vmax analog outputs as well as use them to produce a 5Vmax analog signal representing the power. In addition to these analog signals, there is also a resettable instantaneous over-current relay output. Current flow must be from Load(+) to Load(-) for proper operation.  The PIC_Multiplier is this.  This circuit is used here.

Bill of Materials:

PIC Program:

DC Signal Multiplier

While considering making a constant power DC power supply, I realized that it was quite challenging to come up with a way to multiply DC analog signals. I eventually decided that it’s simply much cheaper and easier to go ahead and use a microcontroller. In this case, a PIC10F322. RA0 and RA2 are used as ADC inputs, and RA1 is used as a PWM output which is passed through a low pass filter to convert it into an analog signal. Finally, RA3 is used to reset the controller if supply voltage drops below an acceptable threshold.

PIC Multiplier Better Quality Image

PIC Multiplier.png

Circuit board design files:

Microchip MPLAB X microprocessor programming files for this device:

PIC10F322 Program