BATTERY CHARGING DEVICE

• US 3,733,534 A
• Filed: 08/25/1971
• Issued: 05/15/1973
• Est. Priority Date: 08/25/1971
• Status: Expired due to Term

• Current Assignee: Seymour Saslow
• Original Assignee: Seymour Saslow
• Inventors: Saslow, Seymour
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/174,611
• Time in Patent Office: 629 Days
• Field of Search: 320/39,40,35,44,43,37,38,23
• US Class Current: 320/143
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

A battery charging device comprising in combination: A TRANSFORMER FOR TRANSFORMING AN AC power line supply into usuable energy; a pulsating charging circuit operatively coupled to said transformer and disposed for charging a battery across a charging terminal (18) supplying a pulsating charging current during each half cycle of AC alternation; sensing circuit means connected to said charging terminal for sensing the voltage charged in said battery during the non-charging 1/2 cycle; a measurement and memory circuit connected to said charging circuit and said sensing circuit means including storage means for storing a charge therein which is a function of said battery charge; and, control means responsive to said voltage sensing and coupled to said charging circuit for changing the rate of charge for a time period measured by said measurement and control circuit.

Claims

1. In a battery charging device having:

a. a transformer for transforming an AC power line supply into usuable energy including an SCR in series with said transformer for charging a battery and a current limiting resistor in series with said SCR and said transformer, said SCR including a control electrode;

b. a pulsating charging circuit operatively coupled to said transformer, SCR and current limiting resistor and disposed for charging a battery across a charging terminal (18) supplying a pulsating charging current during each half cycle of AC alternation;

c. a diode (39) connected to said SCR control electrode, a gating transistor (38) including an emitter connected to said diode and, a control transistor (40) with one electrode connected to said gating transistor base;

d. sensing circuit means connected to said charging terminal for sensing the voltage charged in said battery during the nonchargiNg one-half cycle;

e. a measurement and memory circuit connected to said charging cirucit and said sensing circuit means including storage means for storing a charge therein which is a function of said battery charge;

f. a trickle charge circuit in parallel with said SCR, connected to said charging terminal (18), having a diode (50) and resistor (52) in series, g. control means responsive to said voltage sensing means and coupled to said charging circuit for changing the duration of charge upon a predetermined battery voltage for a time period measured by said measurement and memory circuit, the improvement therein comprising;

h. a second secondary (58), an internal power supply (22) connected to said second secondary (58) including first and second power diodes (60,

     64) in series with said second secondary (58) in parallel with each other in a back-to-back relationship, one of said diodes being connected to the collector electrode of said gating transistor (38) providing half wave rectification to control the firing of said transistor, a tap on said second secondary, a power diode (62) in parallel with power bias resistors (68,

     70) connected to said tap providing rectification of the second half wave, and voltage reference diodes (46, 47, 48,

     49) in series with said power diode (62) said power bias resistors (68,

     70), the emitter of said control transistor (40) being connected to said voltage reference diodes; and

, i. said sensing circuit means being voltage sensing means and including a resistor bridge (80, 82, 84, 86,

     88) connected to said terminal (18), a voltage sensing transistor (92) operatively coupled to said bridge, an amplifier (A) connected to said bridge, an inverter (B) connected to said amplifier (A) inverting said amplifier output, a second amplifier (F) connected to said power section connected to said inverter (B) supplying charging information thereto, and, a disable means (c) connected to said inverter (B) and second amplifier (F) to disable the charge measuring and terminate the main charge.

2. A device as claimed in claim 1, including a charge measurement circuit connected to said disable means (C) including a first transistor (108) biased by said disable means (C), a second transistor (110) and rate limiting resistor (116) connected to be turned on by said first transistor (108) and a memory capacitor (122) connected to said second transistor (110) and charged thereby to a value which is a function of the battery charge.

3. A battery charger as claimed in claim 2, including an overcharge interval circuit (28) for storing in a memory the time required to bring the battery up to 90 percent of its full charge, said overcharge interval circuit including, an amplifier (D) connected to the voltage sensing means (92), said disable means (C), and an overcharge transistor (124), a differential amplifier (126) connected to the collector electrode of said overcharge transistor including a plurality of input resistors (128, 130) in parallel to the plus input of said differential amplifier and a resistor (132) connected to the minus input thereof, an output differential amplifier resistor (134) connected between the differential amplifier and the base of said control transistor (40), said input resistors being connected to one and the other side of said memory capacitor.

4. In a battery charging device comprising in combination:

a. a transformer for transforming an AC power line supply into usuable energy, including a current limiting resistor (204) and an SCR (206) in series with said transformer and current limiting resistor for charging said battery;

b. a pulsating charging circuit operatively coupled to said transformer and disposed for charging a battery across a charging terminal (18a) supplying a pulsating charging current during each half cycle of AC alternation;

c. sensing circuit means connected to said charging terminal for sensing the voltage charged in said battery duRing the non charging 1/2 cycle;

d. a measurement an memory circuit means including storage means for storing a charge therein which is a function of said battery charge; and

, e. control means responsive to said voltage sensing means and coupled to said charging circuit for changing the duration of charge upon a predetermined battery voltage for a time period measured by said measurement and memory circuit, the improvement therein comprising;

f. a tap (13) on said transormer, a first NPN transistor (214) connected to said tap at its base, a second NPN transistor (215) whose base is connected to the collector of the first NPN transistor, a measurement capacitor (22)0 charged by said second transistor collector to a value corresponding to said battery charge, said measurement capacitor (22)0 serving to interrogate the battery and record the battery voltage thereon;

g. a current transformer (222) fed by said transformer, a diode (223), resistor (225), and memory capacitor (227) in series with said current transformer secondary, said capacitor (227) memorizing the charge on said battery; and

, h. a control SCR (222) operatively connected between said measurement capacitor (220) and said memory capacitor (227) by a switch (238), said switch (238) connected to said memory capacitor (227) acting to fire said control SCR (222), whereby said measurement capacitor charge increases with charging time so that when said battery charge reaches about 90 percent of the full charge said measurement capacitor discharges at a predetermined rate and causes the charging device to turn off when about 110 percent of the energy is restored to the battery under charge.