Abstract: A system for measuring power in an electrical distribution circuit having at least three wires includes a Hall-effect generator directly coupled to one of the live wires of the circuit and current transformers coupled to the other live wires of the circuit. The output of each current transformer is magnetically linked to the Hall-effect generator. The excitation current for the Hall-effect generator is derived from the line potential between the live wires. The Hall-effect generator acts to produce an output whose magnitude is directly proportional to the product of the vector sums of the currents flowing in the live wires and the potential between the live wires. This power indicative output may be accumulated to produce an indication of energy consumed by a load connected to the live wires. A high frequency A.C. bias is applied to the Hall generator in order to linearize the output of the generator.

Abstract: A gain switching apparatus for a signal is controlled by a switching function formed as a function of the signal. The apparatus is provided with a circuit for reducing errors due to common frequency components in the switching function and in the signal being switched thereby. In order to reduce DC error resulting from multiplication of the switching function by a parameter representing the switched signal, the common frequency component of the switching function is substantially eliminated and replaced by a component at a frequency which is a multiple of the common frequency. A simplified logic circuit is provided to perform the frequency multiplication and the resultant error reduction.

Abstract: A direction sensitive pulse initiator for a watthour meter having a rotating disc. A pair of sensors sense the presence of an indicator portion or portions, on the rotating disc or on an auxiliary disc, to produce electrical signals which are decoded to initiate clockwise rotation pulses and/or counterclockwise rotation pulses. The pulses are available to be recorded for compiling a record of metered power over a period of time. The sensor electrical signal outputs are decoded so as to determine if the previous exit direction of the indicating portion is the same as its present entry direction, and if this is true a rotation pulse of the appropriate direction is produced.