GB1103763A - Improvements relating to electrical metering arrangements - Google Patents

Abstract

1,103,763. Counters. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. 23 Nov., 1964 [21 Nov., 1963], No. 46045/63. Heading G4D. [Also in Division G1] An electricity meter for registering, in addition to the total quantity consumed, the quantity consumed at a rate of consumption in excess of a predetermined rate detects the rate of consumption by comparing the repetition frequency of electrical pulses generated in response to the rate of consumption with a reference frequency representative for the predetermined rate. The rotor disc 4 of an induction-type motor meter 1 produces pulses at a rate proportional to the speed of rotation of the disc, either by the cam-and-switch arrangement 7, 8 shown or by the use of a slotted disc rotating between energized and feedback coils of an oscillator which produces a train of pulses at a rate dependent on the speed of the slotted disc. The slotted disc may be coupled with the rotor disc 4 or the disc 4 may itself be suitably slotted. The pulses control the speed of rotation of a motor 9 and a fixed speed motor 15 is driven at a rate corresponding to the reference frequency. At the predetermined rate of consumption gearwheels 11 and 14 rotate at the same speed in the same sense; at lower rates the gear 18 is driven in a sense such that the gear 19-which is of pawl-and-ratchet type-does not drive the register 16, but at higher rates the register 16 is driven. A second set of gears 25, 26, 27 and associated register 23 may be similarly controlled by motors 9 and 15, but through different ratio intermediate gears, to register consumption at a rate in excess of a second, and higher, predetermined rate. The registration of quantity consumed at an excess rate may be arranged to take place only during specified peak-load periods, a switch 13 completing the circuit to motor 9 only during these periods. This switch may be made automatically by the fixed speed motor 15. To allow for the possibility that power failures will cause the time-switching function of motor 15 to fail, the motor may incorporate a conventional spring-and-escapement reserve switching mechanism.