Mini Current Transformer
Generally used in measuring instruments, as the secondary transformer of the instrument, convert 1 A, 5 A into mA current, For instrument use;

Specifications
Current range:5 - 200 A；
Secondary signal:2 m A- 200 m A；
Withstand voltage rating:2 / 3 KV；
Rated frequency:50 / 60 HZ；
Flame retardant properties:UL 94 - V 0；
Use environment:- 25℃-50℃。

Type A: Dual pins, usually smaller in size and smaller in current range, usually using ultra-fine crystal cores with higher precision;

Type B: Four-pin parallel pins, usually the current is from large to small, usually using ultra-microcrystalline iron core, so the accuracy is higher；

Type C: Front and rear parallel pins, usually the current is from large to small, usually using ultra-microcrystalline iron core, so the accuracy is higher;

Class D: Three-pin, usually use silicon steel wound core, so the accuracy is not as good as the ultra-microcrystalline core, but the load capacity is strong.

Category	Model	Rated input	Recommended turns ratio	load	Accuracy	size
		(Maximum input)	Recommended turns ratio	load		A	B	C	D	Z	P
		A	T	Q		mm	mm	mm	mm	mm	mm
A	WCT4.5	5(20)	1000	10	0.2	19.2	20	11	4.5	12
A	WCT5	5(20)	1000	10	0.2	19	18	10.5	5	12
B	WCT5.6	5(20)	1000	10	0.2	19	20	11	5.6	6.4	15.2
B	WCT7	5(40)	2500	20	0.1	23.7	24.5	11	7	15\19	10
B	WCT8.9	20(80)	2500	50	0.1	26.4	28.2	17	8.9	15\19	16
C	WCT7.5	10(60)	2500	20	0.1	23.5	24.5	11.2	7.5	18	8
C	WCT13.2	30 (90)	2500	50	0.1	37.7	28.5	14	13.2	24.7/33	13
D	WCT9.5	20 (60)	1000	100	1.0	23.8	23.8	11.1	9.5	15.24	7.62
D	WCT11.4	30(90)	1000	100	1.0	30.2	30.3	14.3	11.4	20.32	10.16
D	WCT14.6	S30(150)	1000	100	1.0	38.1	38.1	15.9	14.6	33	10.16
D	WCT19.05	100(150)	1000	100	1.0	44.5	44.5	14.3	19.05	35.56	10.16
D	WCT23.8	150(200)	1000	100	1.0	55.6	55.6	20.6	23.8	45.72	12.7

case1：

The typical application circuit is shown as in Fig. 1. The secondary load is basically zero. The precision transformer should be a zero-load transformer. Through the operational amplifier, the user can adjust the value of the feedback resistor R to obtain the required voltage output at the output. The capacitor C and resistor r are used to compensate the phase difference. If the user uses software compensation or does not need to compensate the phase difference, the capacitor C and resistor r can be left unconnected. The operational amplifier in the figure is a general operational amplifier; the accuracy of the feedback resistor R in Figure 1 is related to the accuracy requirements of the output voltage; D 1, D 2 diodes are used for 1 N 4148 protection, and can be left out; C 0 is an anti-interference capacitor The capacitance is determined according to the circuit and operational amplifier technical parameters, otherwise it will cause the output signal to oscillate

Case2：

The typical application circuit is shown as in Fig. 2. And the resistance R can get the output voltage directly. V 0 = R* I 0; R is recommended to use the recommended value, too high will easily saturate. C in Figure 2 can play a role in phase compensation, no phase requirement can be ignore。