D.C. Stepped-up voltage transformerless battery charger

• US 4,510,431 A
• Filed: 02/25/1982
• Issued: 04/09/1985
• Est. Priority Date: 06/27/1980
• Status: Expired due to Fees

• Current Assignee: Harry L. Winkler
• Original Assignee: Harry L. Winkler
• Inventors: Winkler, Harry L.
• Primary Examiner(s): Beha, Jr., William H.
• Assistant Examiner(s): JONES, JUDSON
• Application Number:
  US06/352,110
• Time in Patent Office: 1,139 Days
• Field of Search: 363/21, 320/1, 320/39
• US Class Current: 320/103
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: Y10S 320/15 Polarity control

Abstract

A battery charger that takes energy from a battery and steps-up the voltage to charge another battery.

The direct current, going into the charger'"'"'s circuit goes through the voltage regulator and then to a switching voltage regulator (the integrated circuit) and a few external components which generates the energy to charge the output capacitor. The output capacitor voltage is controlled by a resistive voltage divider network, and energy stored in the output capacitor is transferred through a diode and a current limiter to charge the battery.

Claims

1. An apparatus for charging a battery from a direct current voltage source comprising:

a filter capacitor connected across the input voltage terminals with the positive lead of said capacitor connected to the positive voltage terminal of said voltage source and the negative lead of said capacitor connected to the negative terminal of said voltage source;

a two-position single-pole power switch with means for connecting said switch to be in a conductive mode when said switch is in the ON position and further means for connecting said switch to terminate the power from said voltage source when said switch is in the OFF position;

a circuit protector comprising a fuse and a first rectifier, means for connecting one end of said fuse to said power switch and means for connecting said rectifier to be poled to blow said fuse upon receiving reverse polarity of said voltage source;

an input voltage regulating system comprising a first and a second resistor, one power transistor and one zener diode, means for connecting one end of the first resistor to the cathode end of the first rectifier, to the far side of said fuse, and the collector of said transistor, further means for connecting the other end of said resistor to the base of said transistor as well as to the cathode end of said zener diode, means for connecting the anode end of said zener diode to the ground, means for connecting the emitter of said transistor in series with the second resistor and to the input of the current limiter resistor, means for controlling said regulator, the said zener diode has a pre-determined voltage break-down region upon conduction, diverts current from the base of said transistor thereby controlling said transistor'"'"'s emitter voltage;

an oscillator having first, second, and third inputs and having an output, said first input of said oscillator is controlled by a first control means comprising a current limiter resistor and a current limit sense, means for connecting said current limiter resistor to said current limit sense, further means for connecting said current limit sense to said first input of said oscillator and means for said first control to turn off a power switch transistor in the switching system upon said current limit sense detecting a pre-determined voltage drop across said current limiting resistor thus protecting the battery charger'"'"'s circuit from an overload;

a switching system comprising a fourth resistor, said power switch transistor, an inductor, a second rectifier, and an output capacitor, means for connecting said fourth resistor in series between said output of said oscillator and the base of said power switch transistor, means for connecting the emitter of said power switch transistor to ground, means for connecting said inductor in series between said current limit resistor and the collector of said power switch transistor, means for connecting said rectifier in series between said collector of said power switch transistor and said output capacitor, further means for connecting the negative terminal of said output capacitor to ground, means for said inductor to receive energy from said voltage source, means for said inductor to store energy and further means for transmitting said inductor'"'"'s received and stored energy through said rectifier to charge said output capacitor, electronic switching means having an ON-state and an OFF-state, means for connecting said electronic switch to provide a current path to load said inductor when in the ON-state condition and further means for providing said inductor a current path to charge said output capacitor with said stored energy when said electronic switch is in the OFF-state condition, in normal operation said electronic switch is cycled ON and OFF at the same rate as the frequency of said oscillator;

means for regulating the charge level of said output capacitor comprises a resistive voltage divider network comprising a fifth resistor and a potentiometer, means for connecting one end of said resistor to said output capacitor and means for connecting the other end of said resistor to the first part of said potentiometer, further means for connecting the second and last parts of said potentiometer to the ground, further comprising a second control means for said second input of said oscillator wherein said second control means comprises an error amp, a 1.2 volt reference and a third rectifier, means for connecting the first part of said error amp to said first part of said potentiometer and means for connecting the second part of said error amp to the first part of said 1.2 volt reference and means for connecting the last part of said 1.2 volt reference to ground and further means for connecting the last part of said error amp to said second input of said oscillator, means for connecting said rectifier anode end to the ground and cathode end to said second input of said oscillator, said second control means wherein the voltage at the noninverting input is more negative than the 1.2 volt reference, the oscillator is gated ON, when the voltage at the noninverting input is more positive than the 1.2 volt reference, the oscillator is gated OFF thus regulating the charge level of the output capacitor;

a third control means for said third input of said oscillator wherein said third control means comprises a frequency timing capacitor, means for connecting said capacitor in series between said third input of said oscillator and ground, means wherein said timing capacitor is used to determine the frequency of said oscillator and further means for controlling said oscillator'"'"'s frequency whether increased or decreased by said first control means or said second control means of said oscillator;

a system of transferring energy from said output capacitor to charge a battery comprising a fourth rectifier and a lamp, means for connecting said rectifier and said lamp in series between said output capacitor and said battery to be charged, means for transferring said energy from said output capacitor to said battery to be charged.