Automatic electric battery charging apparatus
First Claim
1. Automatic battery charging apparatus, including terminating means for terminating a phase of the charge when the rate of rise of a control signal varying with battery voltage falls below a given value, including a voltage-controlled pulse generator controlled by the control signal to produce a train of pulses whose repetition rate varies with the control signal, and means for initiating termination in response to the rate of change of the said repetition rate falling below a given value.
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Accused Products
Abstract
Automatic battery charging apparatus in which a control signal is generated by subtracting a signal representing a fraction of the mains supply voltage from the battery voltage so that the control signal represents the state of charge of the battery irrespective of variations in the mains voltage. The charge is terminated when the rate of rise of the control signal falls below a predetermined value; this condition is sensed by sampling the output frequency of a voltage controlled oscillator whose frequency is directly proportional to the control signal. In one arrangement the output frequency is fed to an up-down counter for a sampling period (2 minutes) with the counter counting up and then, after an interval of 30 minutes, the output frequency is fed to the counter for a further sampling period (1 minute 55 seconds) with the counter counting down. If the counter fails to return to zero at the end of a down count the charge is terminated.
18 Citations
12 Claims
- 1. Automatic battery charging apparatus, including terminating means for terminating a phase of the charge when the rate of rise of a control signal varying with battery voltage falls below a given value, including a voltage-controlled pulse generator controlled by the control signal to produce a train of pulses whose repetition rate varies with the control signal, and means for initiating termination in response to the rate of change of the said repetition rate falling below a given value.
Specification