AUTOMATIC BATTERY CHARGING REGULATOR FOR EMERGENCY LIGHTING AND POWER SYSTEMS

• US 3,659,181 A
• Filed: 03/12/1970
• Issued: 04/25/1972
• Est. Priority Date: 03/12/1970
• Status: Expired due to Term

• Current Assignee: Edward Bembenek
• Original Assignee: Edward Bembenek
• Inventors: Bembenek, Edward
• Primary Examiner(s): Shoop, Jr., William M.
• Application Number:
  US05/018,918
• Time in Patent Office: 775 Days
• Field of Search: 320/39,40,22
• US Class Current: 320/146
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: Y10S 320/22 Line impedance, e.g. resistor

Abstract

A voltage sensing circuit monitors the battery voltage and places the battery on '"'"''"'"''"'"''"'"'fast charge'"'"''"'"''"'"''"'"' rate through a silicon controlled rectifier, when the monitored battery voltage drops to a predetermined value. When the battery has charged to a certain value, the battery is automatically returned to a '"'"''"'"''"'"''"'"'trickle charge'"'"''"'"''"'"''"'"' rate through a parallel circuit. A clamping circuit maintains the circuit in '"'"''"'"''"'"''"'"'trickle'"'"''"'"''"'"''"'"' charge condition until the battery voltage is again sensed to have fallen below the first aforementioned desired predetermined value preventing '"'"''"'"''"'"''"'"'hunting'"'"''"'"''"'"''"'"' of the battery by providing control with a voltage differential between the '"'"''"'"''"'"''"'"'trickle'"'"''"'"''"'"''"'"' and '"'"''"'"''"'"''"'"'fast'"'"''"'"''"'"''"'"' charging rates.

Claims

1. For a battery supplying power selectively to a load, a source of unidirectional power, a first charging circuit including impedance means connecting said battery across said power source for charging at a predetermined slow rate, a second charging circuit including switching means for selectively applying a low impedance shunt path across said first charging circuit for causing a relatively much faster charging rate of said battery, circuit means for monitoring the voltage across said battery terminals, said monitoring circuit means being actuated from a first condition to a second condition in response to voltage at said terminals decreasing to below at least a predetermined level, said monitoring circuit means being actuated from said second condition to said first condition in response to voltage to said terminals increasing a certain amount above said predetermined level, said second charging circuit being responsive to actuation of said monitoring circuit means from said first condition to said second condition for applying said low impedance shunt path across said first charging circuit for increasing charging rate of said battery to said faster rate, characterized in that there are provided, voltage differential means responsive to actuation of said monitoring means to said first condition for providing a selected differential of said monitored voltage for actuating said monitoring means to said second condition.

2. The circuit of claim 1 wherein said voltage differential means includes, clamping means responsive to actuation of said monitoring means back to said first condition for applying a signal to said monitoring means of a character for maintaining said monitoring means in said first condition preventing operation of said shunt path under conditions where said first charging circuit is operatively charging said battery.

3. The circuit arrangement of claim 2 wherein, said shunt switching means includes a silicon controlled rectifier having its anode-cathode circuit in shunting relation to said first charging circuit for applying a low impedance shunt path across it under conducting conditions of said rectifier.

4. The circuit of claim 3 wherein, said Battery monitoring circuit includes an adjustable voltage divider network connected across said battery terminals, and a second silicon controlled rectifier with its gate electrode connected to a selected point on said voltage divider network, and with its cathode-anode circuit across said power source for placing said second rectifier in conducting condition when said monitored battery terminal voltage increases said certain amount above said predetermined level, and wherein the gate electrode of said first silicon controlled rectifier is connected to the anode circuit of said second silicon controlled rectifier for maintaining said first silicon controlled rectifier in nonconducting condition under conditions where said second silicon controlled rectifier conducts through its anode-cathode circuit.

5. The circuit of claim 4 wherein said monitoring means includes avalanching means connecting said gate electrode of said second rectifier to said voltage divider network for applying a firing signal to said second rectifier when said monitored voltage increases above said predetermined level.

6. The circuit of claim 5 wherein, said clamping means is responsive to conduction of said second silicon controlled rectifier for applying an increased voltage to said avalanching means for maintaining said avalanching means at a certain amount above its avalanching value for maintaining said circuit in slow charging condition under conditions where said power source maintains said battery terminal voltage at least at said certain amount above said predetermined level.

7. The circuit of claim 6 wherein, said clamping means includes a transistor and interconnecting circuit means responsive to conduction of said second silicon controlled rectifier for placing said transistor in conducting condition when said second silicon controlled rectifier conducts for applying a low impedance path across a selected portion of said voltage divider network for increasing the magnitude of the voltage signal applied to said avalanching means for clamping said avalanching means in avalanched condition with a voltage signal a predetermined amount above its avalanching value.