Simple phase sequence indicator

As shown below. When using it, you only need to connect the three wires X, Y, and Z to the three-phase circuit, and the phase sequence of the three-phase alternating current can be easily identified by turning off and on the neon tube. If the neon tube lights up, then X, Y, and Z are connected to phases A, C, and B of the power supply respectively. On the contrary, if the neon tube does not light up, then X, Y, and Z are connected to phases A, B, and C of the power supply respectively. The resistor in the circuit can be a 1/8W carbon film resistor, and the capacitor must have a withstand voltage greater than 400V. Neon tubes can be used as neon tubes in fluorescent lamp starters.