Simple AC wattmeter circuit
If you are looking for AC power measurement. To use it just a little, which is not worth it. When we need to buy an expensive tool. Because use little does not need high accuracy. I would like to propose the concept of wattmeter circuit in such a way easy as it was.I collected all three circuit, as follows.
Easy in-line rf wattmeter circuit
This is a little ideas of Easy In-line RF wattmeter circuit, it is insensitive to frequency, so calibration will be correct better than a wide frequency spectrum.
For example the whole amateur HF spectrum; If the values of L2,
the voltage divider at capacitors C1 and C2, and the resistances of R1 and R2 are selected right, R1-R2 and C1-R2 should be matched for best outcome.
Usually, The R1 and R2 must be small compared to the reactance of L2, for to avoid any important effect on the current of L2 , which is induced by the transmission line current flowing through L1.
The lower frequency limit of the bridge is defined by the R1-R2/L2 ratio,
and the cut off point at the value of R1-R2 becomes great with reference to the reactance of L2 at that frequency point.
The amp meter is 100uA – 200uA, it is limited current by the R6.
The S1 uses to choose a range of frequency to Low or High.