This version of the test lights a lamp when the ring touches the tortuous wire. The SCR can be the TIC106 and R1 is 10k to 47k. For a 6 V lamp, supply the circuit with 9 V to compensate for the voltage drop in the SCR. 50 to 200 mA lamps can be used, but for currents above 50 mA do not use a battery, but a source. To disarm the circuit, turn the power off for a moment.
