Analysis of the circuit
Inside the plastic case. found 2 half ring magnetic cores, and a PCB with 2 Hall effect sensors(marked 602C, can't find part number), 1 TS952I operational amplifier, 1 MC33272 2-ch OPA, 1 Analog switch (guess, Top marking: E3D AA).
Looks like some instrumental amplifier structure, final stage gain can be switched by analog switch. 2 Hall effect sensors and ring magnetic core can eliminate earth magnetic field.
1: red - V+, should be 5V, 5V at least, and max rated 5.25V
4: green - GND
6: white - Sensor voltage output, High range: ~3mV/A, Low range:~30mV/A, neutral at around 2V
5: black - GND
8: yellow - range switch, H:700A, L:70A
The cable is shielded.
Input and output signal
DCPower supply 5V +/- 5%
Range switch: should be normal CMOS/TTL level, i.e. VIL: 0.8V, VIH: 2V
Output signal: voltage, 2V for +/- 0A, and (30mV or 3mV) / A, when current flows alone the arrow, output voltage goes higher. Output
Frequency/pulse response.(Simple current step test, DC power supply with current limit, oscilloscope Rigol DS1102E, and some switch. Wire winded 10T. Maybe should use some MOSFET's and a signal generator to test)
DC supply current limit 3A
Oscilloscope: y:200mV/div, DC, 1X, BW limit 20MHz, x: 50us/div, trigger: rising edge for tr, falling edge for tf
Sensor Range: Low
tr (0A to ~50A): 120us
tf (30A to 0A): 200us
Thanks for reading!