GB642295A - Improvements relating to rectifier circuits - Google Patents

Abstract

642,295. Rectifying; charging and discharging batteries. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Sept. 9, 1948, No. 23695. Convention date, Feb. 12. [Classes 38 (ii) and 38 (iv)] In a rectifier circuit supplying a D.C. load from an A.C. source, particularly a battery charging circuit, signal means are provided responsive to the ripple component of the rectifier output for the purpose of detecting when the rectifier output ceases. In the arrangements described, the signal means is responsive to the voltage drop created by the nipple choke coil 12 in the rectifier 8 output circuit and may comprise a further rectifier 23 connected across the choke and supplying a relay coil 26 actuating normally-closed contacts 27, 28 included in a lamp 30 circuit connected across the load 18 or battery 16, so that in the event of overload resulting in blowing of fuses 4 or 14, or a supply failure, or opencircuit in rectifier 8, the relay becomes de-energized and thereby causes the lamp 30 to light. To keep D.C. out of the rectifier 23 circuit a transformer or condenser may be interposed between the rectifier and choke (Figs. 2 and 4, not shown). Alternatively, an A.C. relay may. be used connected to the choke through either a transformer or condenser (Figs. 3 and 5, not shown) and in the latter case a further lamp may be connected across the relay coil operating inversely to lamp 30. In a further arrangement, Fig. 6 (not shown), the signal means may comprise a glow discharge tube connected across the choke and having characteristics such that it does not respond to the D.C. potential but only to the peaks of the ripple voltage across the choke. Audible or other sensible signals might be used alone or in combination with the visual signal.