GB764963A - Improvements relating to integrators - Google Patents

Abstract

764,963. Watt-hour meters. MYERS, F. H. E. March 3, 1955 [March 4, 1954], No. 6412/54. Class 37. [Also in Group XIX] An instrument for measuring the integral of a physical quantity with respect to time comprises a variable electrical condenser coupled to an instrument which measures the magnitude of the quantity in question and forming the frequency control of a time-base circuit and a counting device connected to indicate or record the number of impulses in the timebase circuit. As described, a wattmeter having fixed coils 1, Fig. 1, and a moving coil 3 has attached to its spindle 6 the movable vanes 7 of a variable condenser having fixed vanes 11. The condenser 7, 11, Fig. 2, is connected in series with a high resistance 13 to A.C. mains supply 14 across a stable source of D.C. consisting of a transformer 15, a full-wave rectifier 16, a smoothing inductance 17, a shunt capacitance 18 and a neon-tube stabilizer 19. When the potential of the condenser 7, 11 rises to a predetermined value it breaks down a discharge tube 20 to apply a voltage to a timebase circuit comprising a capacitance 22 and the winding 21 of an electromagnet which upon energization attracts the armature 23 and a pawl 24 carried thereby steps on a ratchet 25 of a counter which registers watt-hours. The moving plates 7 may be designed to make the repetition rate of the timebase strictly proportional to the magnitude of the physical quantity.