Hello All,

There seems to be a lot of interest in measuring AC
current and AC voltage. I have used this circuit in some
of my designs over the years and I thought it would be
cool to roll it into one device. This is a work in
progress at the present time and should be done in about
a month. I will update the forum and it develops.

The device uses a standard amp probe and voltmeter. You
simply connect the differential amplifier across the
meter movement coil. It is polarity sensitive so be
careful. Adjust the opamp to give 5 VDC for full scale
deflection on the meter movement.

The circuit incorporates a software real time clock, LCD
readout, 128K EEPROM, and a RS232 2400 baud output. It
will output the read values each second. It also store
the values in an EEPROM once every thirty minutes.

The unit features a battery backup to handle power
outages.

Schematic can be seen at http://members.aol.com/cpu8052/ampprobe.gif

A printed circuit board(s) will soon be forth coming.

Circuit improvement(s) are welcome.

Regards,

Charles Bannister