Core Characteristics of 200mA Moving Coil Ammeter

Introduction: The core of a moving coil ammeter is simply measured, and its static resistance, inductance and vibration characteristics are measured.

关键词: Moving coil , ammeter , dynamic

 

01 moving coil movement

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  I have a moving coil ammeter on hand Note that at this time, the moving coil watch core and the outer ferromagnetic shoe have been removed, but the permanent magnet inside it still exists.

▲ 图1.1 动圈电流表表芯

1. Static electrical characteristics

  Use a digital multimeter to measure the DC resistance of the watch core.

Watch core DC resistance:

直流电阻 ：182.4Ω

  Use SmartTweezer to measure the inductance of the watch core, the measurement frequency is 1kHz, and the measured values ​​are as follows:

Core inductance:

电感：2.644mH

2. Rotational characteristics

  Due to the magnetic ring generated by the permanent magnets of the watch core, after the hands are fluctuated, the rotation of the moving coil will generate an induced electromotive force. Measuring this capacitive type with an oscilloscope can display the ringing waveform.

▲ 图1.2.1 测量表芯转动感应电动势

3. Violent current

1. Through current

  Apply 0.0822V to the moving coil current to observe the motion characteristics of the moving coil.

▲ 图1.3.1 动圈在电压驱动下产生的运动

2. Through high current

  Use 5V to apply directly to the moving coil.

▲ 图1.3.2 施加5V电压驱动动圈

  The use of 30V is directly produced for the moving coil. It can be seen that the moving coil remains safe and sound.

▲ 图1.3.3 施加30V电压驱动动圈

 

※ Summary  ※

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  The core of a moving coil ammeter was simply

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● Links to related charts:

• Figure 1.1 Moving coil ammeter movement
• Figure 1.2.1 Measuring the electromotive force induced by the rotation of the watch movement
• Figure 1.3.1 Motion of moving coil driven by voltage
• Figure 1.3.2 Apply 5V to drive the moving coil
• Figure 1.3.3 Apply 30V to drive the moving coil