ZRH-C12 Micro Precision Current Transformers

Thread a turn bus in the performed hole and input the rated current (e.g. 5A), then the secondary side (vice side) will sense a small current of milliamperes (e.g. 2.5mA). Adjust the feedback resistance, though the function of operational amplifier, then you can get the needed voltage at the output terminal.

Practical example：

Feedback resistance  R=5V/2.5mA/=2.0KΩ

If you want the output voltage to be perfectly accurate, you can choose 1.8KΩ as your resistance, in addition, you can cascade an adjustable resistance（300Ω）for fine tuning；Or choose 2.2 KΩ as your resistance, cascading an adjustable resistance (50KΩ) for fine tuning，so that you can get your required accuracy.

Generally, Capacitance’s empirical value will be 0.01-0.033µF. Resistance will be 200-300KΩ adjustable resistance. IC will be OP07 or µA741 or other universally operational amplifier.

Particular illustration：

Set the resistance in parallel at the secondary side of the transformer to get the required voltage. The resistance should not be too large, generally it is no more than 400Ω. If the resistance is too large, linearity of the transformer will be not so good that phase shift will increase.

d. Technical parameters of commonly used product specifications

Note: The above specifications are stock products’ specifications. We can also design for customers according to their requirements.