Battery charger control circuit

• US 3,886,427 A
• Filed: 01/02/1974
• Issued: 05/27/1975
• Est. Priority Date: 10/17/1972
• Status: Expired due to Term

• Current Assignee: Ronald Edwin Long
• Original Assignee: Ronald Edwin Long
• Inventors: Long, Ronald Edwin
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/430,091
• Time in Patent Office: 510 Days
• Field of Search: 320/22,39,40,43,48,37,38
• US Class Current: 320/156
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

To periodically initiate a charging run during storage of the battery charger and battery for long periods of time, ten hertz clock pulses are applied to a first counter normally used to measure the potential of the battery and the output from the first counter is applied to a second counter normally used to measure the rate of change of the potential of the battery until a predetermined count is reached in approximately 2 1/2 days, with the output from the second counter being used to initiate a charging cycle. To avoid relay contact chatter when the battery is disconnected from the battery charger, the rectified alternating current from the battery charger is applied to a circuit that generates a positive pulse which deenergizes the battery charger when the battery is disconnected from the battery charger.

Claims

1. Apparatus for controlling the charging of a battery, comprising:

input means for carrying a signal representing the potential of a battery;

measuring means for geNerating a plurality of energy-level digital signals indicating energy levels of the battery;

timer means for determining when the time between certain of said energy-level digital signals exceed a predetermined maximum time;

control means for selectively reducing and increasing the rate of charging of the battery;

said control means including logic means for causing said control means to reduce the rate of charging of the battery when said time between said certain energy-level digital signals exceeds said predetermined maximum time during a charging run;

said measuring means including a first counter and pulsegenerator means for applying pulses to said first counter, whereby said first counter counts said pulses;

said first counter including a plurality of different order first output means;

said timer means including a second counter having an input terminal for receiving pulses for the counting thereof and a plurality of different order second output means;

one of the first output means of said first counter being connected to the input of said timer means, whereby said timer begins time periods under the control of said control means;

said control means including means for increasing the rate of charging of the battery when at least one of said first and said second counters counts to a predetermined one of said output means while said battery charger is not going through a charging run.

2. Apparatus according to claim 1 in which said control means includes:

battery charger means for applying charge to said battery at a predetermined rate;

hunting-prevention means for generating a signal when said battery is disconnected from said battery charger means and for rapidly terminating the application of charge at said predetermined rate in response to said signal.

3. Apparatus according to claim 2 in which said hunting-prevention means includes:

a capacitor having first and second plates, said first plate being connected to the output of said power supply;

switch means for reducing the rate of charging of said battery charger;

gating means operatively connected to said switching means;

said gating being connected to said second plate of said capacitor, whereby the rectified alternating current from said battery charger passes through said capacitor and causes said gate to enable said switching means.

4. Apparatus according to claim 3 in which said switch means further includes means for resetting said first and second counters when said rate of charging is reduced.

5. Apparatus according to claim 4 in which said measuring means further comprises:

a digital-to-analogue converter having an input electrically connected to said counter and an output whereby said output provides an analogue signal corresponding to the count of said counter;

a comparator having first and second inputs and an output;

said first input being adapted to be electrically connected to said battery;

said second input being electrically connected to the output of said digital-to-analogue converter; and

said pulse generator having an input and an output for applying said pulses to its output when a predetermined potential is applied to its input;

said input of said pulse generator means being electrically connected to the output of said comparator and said output of said pulse generator means being electrically connected to the input of said first counter.

6. Apparatus according to claim 5 in which:

said timer means further includes timer pulse-generator means for generating a plurality of pulses;

said timer pulse-generator means being electrically connected to the input of said second counter, whereby a signal on the output of said second counter indicates the time from the last output signal from said comparator to said measuring means during a charging run.

7. Apparatus for controlling the charging of a battery, comprising:

input means for carrying a signal represenTing the potential of a battery;

measuring means for generating a plurality of energy-level digital signals indicating energy levels of the battery;

timer means for determining when the time between certain of said energy-level digital signals exceeds a predetermined maximum time;

switch means for reducing the rate of charging of the battery when said time between said digital signals is above the predetermined maximum time;

battery charger means for applying a regular charge to said battery;

said battery charger means including terminal means for connection to the terminals of said battery and relay-contact means including relay contacts which cause said battery charger means to be energized when closed and cause said battery charger means to be deenergized when open;

hunting-prevention means for obtaining a signal from said battery charger means when said battery charger terminal is disconnected from said battery;

said hunting-prevention means being electrically connected to said battery charger and to said switch means;

said switch means including relay-solenoid means electrically connected to said hunting-prevention means for causing said relay-contact means to open so as to deenergize said battery charger upon receiving said signal.

8. Apparatus according to claim 7 in which said hunting-prevention means comprises:

a pulse shaping circuit;

a capacitor having first and second plates;

said first plate being electrically connected to said terminal;

said second plate being electrically connected to the pulse shaping circuit;

said pulse shaping circuit being electrically connected to the switch means, whereby said battery charger is deenergized upon the generation of a pulse from said anti-hunting means.

9. Apparatus according to claim 8 in which said measuring means comprises:

a counter;

a digital-to-analogue converter having an input electrically connected to said counter and an output, whereby said output provides an analogue signal corresponding to the count of the counter;

a comparator having first and second inputs and an output;

said first input being adapted to be electrically connected to said batteries;

said second input being electrically connected to the output of said digital-to-analogue converter; and

measuring-means pulse-generator means having an input and an output for applying a series of pulses to its output when a predetermined potential is applied to its input;

said input of said measuring-means pulse-generator means being electrically connected to the output of said comparator and said output of said measuring-means pulse-generator means being electrically connected to the input of said counter.

10. Apparatus according to claim 8 in which:

said timer means comprises;

a timer counter;

said timer counter having an input and at least one output;

timer pulse-generator means for generating a plurality of pulses;

said timer pulse-generator means being electrically connected to the input of said timer counter, whereby a signal on the output of said timer counter indicates the time from the last output signal from said comparitor to said measuring means.

11. Apparatus according to claim 1 in which said control means includes:

push-button means; and

switch means for increasing the rate of the charging upon either the depressing of the push-buttom means switch or the reception of a predetermined output signal from said logic means.

12. Apparatus according to claim 11 in which said logic means further includes means for deenergizing portions of said timer means and measuring means and energizing other portions of said timer means and measuring means after said rate of charging has been decreased;

said means for energizing, including means for energizing said first and second counters and said first pulse generator and deenergizing said second pulse generator.

13. Apparatus according to claim 12 in which saiD logic circuit further includes means connecting a certain output of said measuring counter to an input of said timing counter, whereby said timing counter counts one pulse upon said measuring counter counting to said certain output.

14. Apparatus according to claim 1 further including reset means for resetting said measuring counter at the end of a charging run.

15. Apparatus according to claim 14 further including second reset means for resetting said timer at the end of a charging run.