I found a few threads on this, but they were quite old, and many of links were no longer valid.
I need to monitor power going to a heater, 120v AC at approx 100 watts. It should be mostly resistive, but ideally I would allow for some non-resistive component.
Since this is for a temporary testing situation, ideally it would just have a household plug on one end, and a household socket on the to plug in the heating device. An example of this form factor might be the $25 "Kill AWatt" power monitor. But it is only a display, and some have commented about it reporting as much as 50% under the true value for items that are under 60 watts. I have been unable to find published accuracy data for this or other similar devices. If the sensor were not packaged as a unit, like the "Kill A Watt", I could make my own box to house the device and just wire in some power cords.
I suppose I could just obtain a simple 120v to 5v transformer, and wire it in, but I was hoping for something with more processing to be able to adjust for variations in the power supply. There was a thread that suggested using AD536 by Analog Devices. But, I am just not wanting to go to this level of electronics design, and really prefer a single component solution.
There is the $10 Non-Invasive Current Sensor from Spark Fun. But, my electronics training is about 25 years old, and I would rather not try to design a circuit that will make this device work.
Perhaps there is something like this that has already built-in the components to provide a voltage range based on the current draw?
Any products to suggest?