Electronic battery testing device

• US 3,909,708 A
• Filed: 01/02/1974
• Issued: 09/30/1975
• Est. Priority Date: 01/02/1974
• Status: Expired due to Term

• Current Assignee: Keith S Champlin
• Original Assignee: Keith S Champlin
• Inventors: Champlin, Keith S.
• Primary Examiner(s): Smith, Alfred E.
• Assistant Examiner(s): Hille, Rolf
• Application Number:
  US05/430,254
• Time in Patent Office: 636 Days
• Field of Search: 324/29.5
• US Class Current: 324/431
• CPC Class Codes: G01R 31/385 Arrangements for measuring battery or accumulator variables for monitoring G01R31/382
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables

Abstract

An improved self-contained electronic device for testing storage batteries and other dc sources is disclosed. The testing device is electrically connected to the battery by means of temporary spring clips. Adjustments are set to the particular electrical rating and temperature of the battery. The device then employs small-signal dynamic measurements to determine whether or not the battery is capable of delivering a specified amount of power dictated by the battery'"'"''"'"'s rating and temperature. The invention thus provides simple '"'"''"'"''"'"''"'"'pass-fail'"'"''"'"''"'"''"'"' information just as does a conventional load test apparatus but without the disadvantages of the latter.

Claims

1. An electronic device for providing a quAlitative assessment of the capacity of a direct current source of electricity to supply power to a load comprising:

a. electrical means providing a time-varying signal;

b. amplifying means for amplifying signals derived from a timevarying voltage developed across said direct current source of electricity, c. at least two electrical connecting means constructed and arranged for interconnecting said amplifying means, said electrical means and said direct current source of electricity, said connecting means conducting a time-varying current derived from said time-varying signal through said direct current source and sensing said time-varying voltage developed across said direct current source of electricity;

d. display means operably connected to said amplifying means, said display means constructed and arranged to denote first and second qualitative conditions of said direct current source of electricity according to whether the output signal amplitude of said amplifying means is greater or less than a particular critical value; and

e. settable control means for varying said output signal amplitude of said amplifying means relative to said particular critical value in accordance with the electrical rating of said direct current source of electricity, the relative setting of said settable control means linearly related to the reciprocal dynamic resistance of said direct durrent source at the level at which said output signal amplitude equals said particular critical value.

2. Apparatus as set forth in claim 1 including second settable control means for varying said output signal amplitude of said amplifying means relative to said particular critical value in accordance with the temperature of said direct current source of electricity.

3. Apparatus as set forth in claim 1 wherein said electrical means providing a time-varying signal and said amplifying means receive operating power from said direct current source of electricity.

4. Apparatus as set forth in claim 1 wherein each of said electrical connecting means contains both a first conductor and a second conductor separately contacting each output terminal of said direct current source, a pair of said first conductors conducting said time-varying current and a pair of said second conductors sensing said time-varying voltage developed across said direct current source of electricity.

5. Apparatus as set forth in claim 1 wherein said display means includes a meter having scale markings indicating the relative ability of said direct current source to supply rated power.

6. Apparatus as set forth in claim 1 wherein said electrical rating is specified in '"'"''"'"''"'"''"'"'watts'"'"''"'"''"'"''"'"'.

7. Apparatus as set forth in claim 1 wherein said electrical rating is specified in '"'"''"'"''"'"''"'"'ampere-hours'"'"''"'"''"'"''"'"'.

8. Apparatus as set forth in claim 1 wherein said electrical rating is specified in '"'"''"'"''"'"''"'"'cold cranking amperes'"'"''"'"''"'"''"'"'.

9. Apparatus as set forth in claim 3 including voltage regulating means stabilizing the supply voltage of said electrical means providing a time-varying signal.

10. An electronic device for providing a qualitative assessment of the capacity of a direct current source of electricity to supply power to a load comprising:

a. a time-varying voltage source;

b. electrical connecting means constructed and arranged to be connected to each terminal of said direct current source of electricity;

c. first high-gain amplifier means;

d. first resistor means conducting a time-varying current from the output of said first high-gain amplifier means through said direct current source of electricity by means of said electrical connecting means;

e. capacitive means coupling across the input of said first high-gain amplifier means, a signal representative of the sum of the output of said time-varying voltage source and the signal developed across said direct current source of electricity as sensed by means of said electrical connecting means;

f. second high-gain amplifier mEans;

g. second resistor means including settable control means for varying the value of said second resistor means according to the electrical rating of said direct current source of electricity;

h. means capacitively coupling across the input of said second high-gain amplifier means, a signal representative of the sum of signals developed across said first resistor means and said second resistor means;

i. means feeding back a current from the output of said second high-gain amplifier means to said second resistor means, said current inversely proportional to the dynamic resistance of the direct current source; and

, j. display means operably connected to said second high-gain amplifier means and actuated by the amplitude of a signal representative of the output signal of said second high-gain amplifier means, said display means constructed and arranged to denote first and second qualitative conditions of said direct current source of electricity according to whether said output signal of said second high-gain amplifier means is greater or less than a particular critical value.

11. Apparatus as set forth in claim 10 including second settable control means for varying the amplitude of the output voltage of said time-varying voltage source according to the temperature of said direct current source of electricity.

12. Apparatus as set forth in claim 10 wherein said electrical rating is specified in watts.

13. Apparatus as set forth in claim 10 wherein said electrical rating is specified in ampere-hours.

14. Apparatus as set forth in claim 10 wherein said electrical rating is specified in cold cranking amperes.

15. Apparatus as set forth in claim 10 wherein said time-varying voltage source, said first high-gain amplifier means, and said second high-gain amplifier means receive operating power from said direct curent source of electricity.

16. Apparatus as set forth in claim 15 including voltage regulating means stabilizing the supply voltage of said time-varying voltage source.

17. Apparatus as set forth in claim 10 wherein said display means includes a meter having scale markings indicating the relative ability of said direct current source to supply rated power.

18. Apparatus as set forth in claim 10 wherein each of said electrical connecting means contains both a first conductor and a second conductor separately contacting each output terminal of said direct current source, a pair of said first conductors conducting said time-varying current through said direct current source of electricity and a pair of said second conductors sensing said signal developed across said direct current source of electricity.

19. Apparatus as set forth in claim 10 wherein the power supplied to said second high-gain amplifier means is interrupted in synchronism with the output signal of said time-varying voltage source.

20. A system for determining whether a direct current supply, having a dynamic impedance, can deliver a rated power to a load including:

a time varying voltage source, coupled to the supply, the source of predetermined amplitude and of a frequency selected to minimize the contribution of supply reactance to dynamic impedance, a current generating means coupled to the supply and producing an output directly proportional to the time varying source and inversely proportional to the dynamic resistance, means for sensing the current generating means and producing an output responsive thereto, and display means including means to scale the sensing means output according to a selected rated output, and displayably comparing the scaling means output with the selected power rating.

21. The system as set forth in claim 20 further comprising means for predeterminedly fixing the level of the source in response to a selected supply temperature.

22. A pass-fail testing means for determining whether or not a direct current source can supply a rated power to a load including:

power determining means having a. an alternating current excitation means, b. means coupling the excitation meand to the source, c. means sensing the response of the source to the excitation means and producing an output signal in accordance with to the ratio of source a.c. current to source a.c. voltage, d. means for processing the sensing means output and producing an output representative of the relative power delivering capability of the source, settable control means programmable to predeterminedly control the power determining means in response to a selected source power rating, and display means monitoring the processing means and producing an output representative of the qualitative condition of the source.

23. The testing means of claim 22 wherein the control means is further programmable to predeterminedly control the power determining means in response to a selected source temperature.