Hi,
I am trying to make a energy monitoring device that is hooked up to my PC. I have decided to go for the Velleman USB Project board, with 2 A/D inputs and 8 bit resolution.
The input is an inductive sensor device that I have taken from a off-the-shelf energy monitor. The device clamps around the utility (Live) side of the consumer box (at 230V AC).
I have measured the AC voltage across the sensor at various loads and the output ranges from about 100mV AC (when the house is drawing 0.5 KW from the supply) to 1.5V AC (when the house is drawing 5KW from the supply).
The A/D converter in the Velleman USB board is rated at 0 to 5V DC with 8 bit resolution.
I was wondering how to build an instrumentation amplifier, such that the range of the input into the A/D is amplified from (0 to 1.5V AC from the sensor) to (0 to 5V DC to the A/D).
I have looked at the AD620. However, I am concerned that their is not a common Ground between the Velleman Board (0V/5VDC) and the Ground of the input sensor (assuming that I use a bridge rectifier etc to convert the AC signal to DC).
Help would be most greatly received.
Thanks
I am trying to make a energy monitoring device that is hooked up to my PC. I have decided to go for the Velleman USB Project board, with 2 A/D inputs and 8 bit resolution.
The input is an inductive sensor device that I have taken from a off-the-shelf energy monitor. The device clamps around the utility (Live) side of the consumer box (at 230V AC).
I have measured the AC voltage across the sensor at various loads and the output ranges from about 100mV AC (when the house is drawing 0.5 KW from the supply) to 1.5V AC (when the house is drawing 5KW from the supply).
The A/D converter in the Velleman USB board is rated at 0 to 5V DC with 8 bit resolution.
I was wondering how to build an instrumentation amplifier, such that the range of the input into the A/D is amplified from (0 to 1.5V AC from the sensor) to (0 to 5V DC to the A/D).
I have looked at the AD620. However, I am concerned that their is not a common Ground between the Velleman Board (0V/5VDC) and the Ground of the input sensor (assuming that I use a bridge rectifier etc to convert the AC signal to DC).
Help would be most greatly received.
Thanks