Computerized solid state energy meter test system and method of testing

• US 5,821,742 A
• Filed: 11/30/1994
• Issued: 10/13/1998
• Est. Priority Date: 11/30/1994
• Status: Expired due to Fees

• Current Assignee: Radian Research, Inc.
• Original Assignee: Utility Test Equipment Company
• Inventors: Malackowski, Donald W., Carr, John M.
• Primary Examiner(s): Karlsen, Ernest F.
• Application Number:
  US08/347,495
• Time in Patent Office: 1,413 Days
• Field of Search: 324/74, 324/130, 323/222, 364/571.01
• US Class Current: 324/74
• CPC Class Codes: G01R 35/04 of instruments for measuring time integral of power or current

Abstract

A portable energy meter test system for testing energy meters and other related instrumentation on-site is disclosed. The test system utilizes waveform generating circuitry to generate and transmit electrical waveforms to an energy meter to be tested, and sensing circuitry for sensing electrical characteristics corresponding to the transmitted electrical waveform. The test system includes a processor for evaluation and control of the testing procedure. A graphic touch screen is coupled to the processor for displaying information about the energy meter and for displaying test options to the user and allowing the user to control the testing process by touching the screen.

Claims

1. A portable energy meter tester for testing energy meters, and other related metering instrumentation, having a power supply with a boost converter for converting an AC input voltage to a DC output voltage, comprising:

a rectifier circuit ;

an inductor coupled to said rectifier circuit;

a capacitor coupled through a diode to said inductor;

a first solid state transistor coupled to said inductor and coupled through said diode to said capacitor;

a second solid state transistor in parallel with said first solid state transistor, and coupled to said inductor and coupled through said diode to said capacitor;

a first drive circuit connected to and controlling said first solid state transistor for turning on and off said first transistor;

a second drive circuit connected to and controlling said second solid state transistor for turning on and off said second transistor;

said first drive circuit initially turning on said first solid state transistor, and thereby placing said boost converter of said portable energy meter tester into a conducting state, said second drive circuit turning on said second solid state transistor, said second drive circuit turning off said second transistor, and said first drive circuit turning off said first transistor, thereby placing said boost converter of said portable energy meter tester into a non-conducting state.

2. The energy meter tester of claim 1, wherein said first solid state transistor comprises a MOSFET.

3. The energy meter tester of claim 1, wherein said second solid state transistor comprises an IGBT.

4. The energy meter tester of claim 1, wherein said first drive circuit comprises a delay circuit, an amplifier and a current limiting resistor.

5. The energy meter tester of claim 4, wherein said delay circuit comprises a resistor and a second capacitor.

6. The energy meter tester of claim 1, wherein said second drive circuit comprises a second delay circuit, a second amplifier and a second current limiting resistor.

7. The energy meter tester of claim 1, wherein said second delay circuit comprises a second resistor and a third capacitor.

8. The energy meter tester of claim 1, wherein said second solid state transistor turns off before said first solid state transistor turns off due to the delay of the first solid state transistor driver.

9. A portable energy meter tester for testing energy meters, and other related metering instrumentation, having a power supply with a boost converter for converting an AC input voltage to a DC output voltage in the energy meter tester, comprising:

a first generating means for generating a first drive signal;

a first receiving means for receiving said first drive signal;

a first switching means for switching said boost converter of said power supply into a conducting state from a nonconducting state upon receiving said first drive signal, thereby allowing a load current to pass through said switching means;

a second generating means for generating a second drive signal;

a second receiving means for receiving said second drive signal;

a second switching means for carrying a majority of said load current upon receiving said second drive signal, thereby reducing said load current passing through said switching means.

10. The energy meter tester of claim 9, further comprising:

a first disconnecting means for disconnecting said second drive signal from said second drive signal receiving means, such that said load current passes through said switching means;

a second disconnecting means for disconnecting said first drive signal from said first drive signal receiving means, such that said boost converter of said power supply switches from a conducting state to a non-conducting state.