Charge or discharge circuit

• US 6,023,149 A
• Filed: 02/17/1999
• Issued: 02/08/2000
• Est. Priority Date: 08/19/1996
• Status: Expired due to Fees

• Current Assignee: Army Government of The United States Department of The Army
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Pizzi, Raymond J.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/251,990
• Time in Patent Office: 356 Days
• Field of Search: 320/128, 320/137, 320/162
• US Class Current: 320/128
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/007186 obtained with the battery disconnected from the charge or discharge circuit

Abstract

A feedback circuit for passing uniformly constant current relative to cha storing devices is disclosed. An open circuit is disposed between two terminals in a feedback loop and these terminals are interconnected through the charge storing devices to close the open circuit, when the uniformly constant current is to-flow for the purpose of either charging or discharging such devices. The feedback loop is included in a voltage regulator which in the preferred embodiments, is comprised only of an operational amplifier and a resistance.

Claims

1. A circuit for maintaining a uniformly constant current flow relative to at least one charge storing device, comprising:

a voltage regulator with a feedback loop disposed therein about an operational amplifier having a noninverting input, an inverting input and an output, while the feedback loop includes only an open circuit disposed therein between a first terminal and a second terminal, with the output being the first terminal and the noninverting input being the second terminal, while the charge storing devices are connected across the open circuit when the uniformly constant current is to flow relative thereto.

2. The circuit of claim 1 wherein a resistance is connected between the noninverting input and ground to set the magnitude of the uniformly constant current.

3. The circuit of claim 1 wherein a reference voltage is applied at the inverting input to set the magnitude of the uniformly constant current.

4. The circuit of claim 3 wherein the reference voltage is derived from a common node between a zener diode and a resistance which are series connected between a dc voltage source and ground.

5. The circuit of claim 1 wherein the charge storing devices are batteries having positive and negative terminals, and a resistance is connected between the noninverting input and ground while a negative reference voltage is applied at the inverting input, with the resistance and voltage being selected according to the uniformly constant current flow desired when the batteries are connected across the open circuit to be discharged, with at least one negative terminal thereof to the output and at least one positive terminal thereof to the noninverting input.

6. The circuit of claim 5 wherein the batteries are arranged in series across the open circuit.

7. The circuit of claim 5 wherein the batteries are arranged in parallel across the open circuit.