CN104977458A - Battery current detection method of electric energy meter FCT tool - Google Patents

Abstract

The invention discloses a battery current detection method of an FCT tooling of an electric energy meter, which relates to the technical field of performance detection in the production of an intelligent electric meter. It is characterized in that it includes the following steps: the tooling circuit board controls the power-on switch to supply 220V alternating current to the ammeter, and starts to detect voltage items, 485 communication, infrared communication, and write data after the ammeter starts, and controls the power-on switch to turn off the 220V alternating current after completion, and starts The U25 relay starts to discharge the capacitor, and the battery current is connected to sample the current AD, and calculate the battery current value. The invention has the characteristics of simple operation, guaranteeing the performance and quality of each electric energy meter during mass production, and the like.

Description

A battery current detection method for electric energy meter FCT tooling

technical field

The invention relates to the technical field of performance detection in the production of smart electric meters, in particular to a battery current detection method of an electric energy meter FCT tooling.

Background technique

In 2008, the State Grid Corporation decided to comprehensively carry out the construction of the "power user information system" within the system, and then organized the preparation of the State Grid Smart Meter Enterprise Standard, and began to carry out the internal system and electric meter manufacturing enterprises in October 2009. Comprehensive publicity and implementation. In 2011, the whole country entered the peak period of smart meter replacement. The new smart meter standard also puts forward higher requirements for the MCU, with more and more functions. In order to ensure the performance and quality of each electric energy meter during mass production, the FCT single-board inspection must be carried out after the electric energy meter is welded to ensure the production quality.

At present, the method of detecting the battery current by the existing electric energy meter FCT detection tool of the same technology is to measure the communication and voltage communication data items on the 220V AC on the electric meter first, then cut off the power, connect the battery power supply on the electric meter, and measure at this time Check whether the supply current of the battery on the energy meter is normal.

Disadvantages: Since the electrolytic capacitor of the meter will be charged after the 220V AC is connected to the meter, when the meter is powered off, the electricity stored in the electrolytic capacitor will be slowly discharged together with the battery. At this time, the battery current needs to wait for 5 to 8 hours to reach a stable value. seconds, which greatly increases the time for power meter board detection.

Contents of the invention

The purpose of the present invention is to provide a battery current detection method for the FCT tooling of electric energy meters, which has the characteristics of simple operation, guaranteeing the performance and quality of each electric energy meter during mass production, and the like.

In order to solve the existing problems in the background technology, the present invention adopts the following technical solutions: the tooling circuit board controls the power-on switch to supply 220V AC power to the ammeter, and after the ammeter is started, it starts to detect voltage items, 485 communication, infrared communication, and write data. Control the power-on switch to turn off the 220V AC power, start the U25 relay, start the capacitor discharge, connect the battery current to conduct current AD sampling, and calculate the battery current value.

The invention has the advantages of simple operation, ensuring the performance and quality of each electric energy meter during mass production.

Description of drawings:

Fig. 1 is the ammeter capacitor discharge circuit of the present invention;

Figure 2 is a two-stage amplifier circuit composed of two OP07A.

Implementation

The tooling control board is placed in the body of the FCT tooling test bench. There are electronically controlled air pumps, power supplies, test needles, infrared probes, etc. on the table body. The control board of the tooling is connected to one end of the test probe. After placing the circuit board during the test, press the start button, and the tooling will start testing according to the predetermined procedure.

After the electric energy meter is put into the tooling testing platform, press the start button to start testing. 1. The tooling circuit board controls the power-on switch to supply 220V AC power to the meter. 2. After the meter is started, it starts to detect voltage items, 485 communication, infrared communication, and write data. 3. After the completion, control the power switch to turn off the 220V AC, and start the U25 relay to start the capacitor discharge. 4. The battery current is connected to sample the current AD, and calculate the battery current value.

Referring to Figure 1, the FD signal is the relay control signal of the tooling control chip. When the level is high, the pins 1 and 3 of the relay are closed, and when the level is low, the pins 1 and 3 of the relay are disconnected. The VCC signal is the positive pole of the CPU5V power supply of the meter (the positive pole of the capacitor), and the GND is the negative pole of the CPU5V power supply of the meter (the negative pole of the capacitor). Both pins are directly connected to the test points on the meter by the FCT tooling probe. The discharge time of the electrolytic capacitor is calculated as T=RC=1 ohm×400uF=400US. We use the method of discharging for 1 second to discharge, and the discharge is more thorough.

Referring to Figure 2, R95 is a sampling resistor. The battery current flows from CIN_1 through R95 and out of COUT_1. After amplifying the voltage across R95, it is sampled by AD and output to the AD sampling pin of the tooling CPU.

work process:

After the 220V power supply of the watt-hour meter is powered off, the tooling circuit board controls pins 1 and 3 of U25 to close for 1 second to discharge, then disconnect and connect to the battery on the watt-hour meter for power supply, amplify the current and perform AD sampling. The detection time of battery stable current is greatly shortened. Increased production efficiency.

Figure 2 Amplifying circuit calculation method:

Vad=Vr95(Rf1/R94)(R102/R99).

Claims (1)

1. A kind of electric energy meter FCT tooling battery current detection method is characterized in that it comprises the following steps: The tooling circuit board controls the power-on switch to supply 220V AC power to the meter; After the meter is started, it starts to detect voltage items, 485 communication, infrared communication, and write data; After completion, control the power-on switch to turn off the 220V AC, and start the U25 relay to start the capacitor discharge; The battery current is connected to sample the current AD and calculate the battery current value.