Wattmeter measures and displays true AC watts over a wide range.

[saunj]

This device was made to tryout the MC1494 four-quadrant multiplier and is housed in a recycled enclosure instead of my usual handmade oak cabinets. The voltage and current transformers are also recycled. It also measures and displays the mean current and voltage, and calculates accumulated watt-hours. All three channels are third-order filtered before 10-bit digitizing by a 14M2 Picaxe. While normally used standalone, there is a BNC connector to view the current waveform on an oscilloscope, and a RS-232 D connector for logging.
For full details go to http://projects.worsleyassociates.com and click on AC Wattmeter.

 

[MPep]

Hi John,

What a cool project
Never heard of the MC1494, datasheet is here

MPep

 

[John West]

I really like the positively "homebrew" styling of the case. Very retro. Well done.

 

[boriz]

Could this device be used as a PID assist for rapid PID loop applications? Like balancing robots and Segway type stuff?

 

[saunj]

I don't even know what PID is

Could this device be used as a PID assist for rapid PID loop applications? Like balancing robots and Segway type stuff?

Probably not, whatever PID is. In any case, it is not rapid. Or were you referring to the multiplier?

 

[John West]

A proportional–integral–derivative controller (PID controller) is a generic control loop feedback mechanism (controller) widely used in industrial control systems – a PID is the most commonly used feedback controller. A PID controller calculates an "error" value as the difference between a measured process variable and a desired setpoint. The controller attempts to minimize the error by adjusting the process control inputs.

Yep, probably just the multiplier.