GB1436819A - Battery charger control circuit - Google Patents

Abstract

1436819 Battery charger control LESTER ELECTRICAL OF NEBRASKA Inc 2 Dec 1974 [2 Jan 1974] 52065/74 Heading H2H A battery charger control circuit comprises a charging run termination circuit for terminating charging runs when the rate of charging of the battery falls below a preset rate, and a turn-on circuit for periodically initiating new charging runs, with at least one counter being alternately connected by a control into the termination circuit for use in measuring the rate of charging, and into the turn-on circuit for use in measuring the time since a run has been terminated. As described a battery 14 is charged by means 12 which is controlled by a switching circuit 22. During a charging run the battery voltage is applied to one terminal of a comparator 55 and that from the output of D1A converter 58 controlled by a counter 60. Whenever the battery voltage rises above that of the converter 58 a pulse is supplied by circuit 85 to trigger multivibrator 62 to increment the counter 60. When, during a charging run, the counter reaches a predetermined intermediate value, a multivibrator 29 is energized and supplies, e.g. 1-72 Hz pulses to a counter 73 via gate 77. This counter is reset to zero by each output from circuit 85 and hence measures the time between attainment of successive energy levels by the battery. If this time reaches, e.g. 40 minutes, the counter 73 overflows and actuates detector 31 to cause circuit 22 to switch the charger off. Multivibrator 62 is now energised to apply, e.g. 10 Hz pulses to the counter 60 which applies a pulse each time it fills via conductor 28D and gate 77 to counter 73. If a charging run has not been manually initiated in a period, e.g. 2¢ days, the counter 73 will fill and cause circuit 22 to initiate a charging run via gate 74. When the battery is removed from the charger relay contact bounce within circuit 22 is prevented by a logic circuit 76 which releases the relays. The counters 60, 73 are reset at the end of a charging period by a circuit 89. Details of the circuits 22, 85, 89, 76 are supplied, Fig. 2 (not shown) and Specication 1,414,359 is referred to.