Circuitry for controlling the reflected torque on a generator driven by a fluid meter

• US 4,489,290 A
• Filed: 02/25/1983
• Issued: 12/18/1984
• Est. Priority Date: 02/25/1983
• Status: Expired due to Fees

• Current Assignee: America Meter Company
• Original Assignee: Singer Company (SVP Holdings Ltd.)
• Inventors: Warner, Richard C.
• Primary Examiner(s): Hickey, R. J.
• Application Number:
  US06/469,559
• Time in Patent Office: 662 Days
• Field of Search: 320/2, 320/39, 320/57, 320/61, 322/1, 322/35, 322/7, 322/8, 322/89-93, 322/28, 322/29, 290/43, 290/52, 290/54
• US Class Current: 322/35
• CPC Class Codes: G01F 15/063 using electrical means
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle

Abstract

The output of an electrical generator driven by a meter is coupled to a load through circuitry for limiting the reflected forces placed on the meter.

Claims

1. In combination with a fluid meter having a rotating output shaft coupled to drive an electrical generator, an arrangement for coupling the output of the generator to a load so that the generator is prevented from supplying output current at speeds of said output shaft below a predetermined threshold speed in order to limit the loading forces applied to said output shaft at those lower speeds, said arrangement comprising:

rectifier means for rectifying alternating current to direct current, said rectifier means having an input and an output;

means for connecting said rectifier means input to the output of said generator;

threshold means connected to said rectifier means output for preventing the flow of current of said load when the voltage level at said rectifier means output is below a predetermined threshold voltage; and

current limiting means coupled between said rectifier means output and said load for preventing the current flowing from said rectifier means output to said load from exceeding a predetermined limit value.

2. The arrangement according to claim 1 further including a resistor in series with said threshold means and said current limiting means to provide a linear slope to the rectifier means output current as the speed of said output shaft increases above said predetermined threshold speed.

3. The arrangement according to claim 2 wherein said threshold means comprises a zener diode.

4. The arrangement according to claim 2 wherein said current limiting means comprises a current regulator diode.

5. The arrangement according to claim 4 wherein said load includes a rechargeable battery.

6. The arrangement according to claim 5 further including a second zener diode connected across said rechargeable battery.

7. In combination with a fluid meter having an output shaft which rotates at a speed which is a direct function of the flow rate of fluid passing through said meter:

an electrical generator coupled to said output shaft;

a full wave diode bridge, said bridge having its input terminals connected across the output of said generator;

a resistor;

a zener diode;

a current regulator diode;

means for connecting said resistor, said zener diode and said current regulator diode in series, with said diodes having opposite polarities;

means for connecting one end of said series connection to the output of said bridge; and

means for connecting the other end of said series connection to a load.