Abstract: The coupler inserts in an RF transmission line and produces a pair of DC signals whose level is representative of the magnitude of forward or reverse power flow therethrough.Power flow is sensed via a pair of non resonant loops, each of which is terminated and oriented such that AC signals, whose amplitudes correspond to the forward or reverse power flow magnitude, are produced. Since the RF signals produced by the loops are dependent on the RF power flow frequency, unique circuitry processes the RF signals and compensates for this frequency dependence whereby the processed AC signals are substantially frequency independent.Also disclosed are improved rectification circuitry, and a means to compensate the coupler against error due to thermal drift of coupler components.

Abstract: A coupler series connects in the power line to be monitored. Sensing circuitry within the coupler senses power flow in each direction of the power line, and produces D.C. signals representing the magnitude thereof. The D.C. signals appear at contacts on the body of the coupler.A housing is provided with a cavity for receiving the coupler. Contacts in the housing adjoin the cavity and are aligned to connect to the coupler contacts. A D.C. activated meter is mounted in the housing, and is electrically connected through a switch to the housing contacts.In operation, the coupler is series connected in the line and, when power is to be monitored, it is secured within the housing. By operating the switch, a user may monitor power flow in either direction down the line.