System in the discharge tube at both ends of the normal operation of the system voltage should be less than the sustain discharge voltage, otherwise it will produce continued flow problem. To maintain the voltage of the glow discharge value greater than a voltage maintaining arc discharge value.
Method for measuring voltage value of tube discharge. Different varieties of discharge tube, which maintain the discharge voltage value of the difference is relatively large. General in the practical application, in the glow discharge is not easy to have a freewheeling, in an arc region may produce continued flow (because to maintain the arc zone of freewheeling required voltage value is smaller than maintain a glow discharge voltage value), this time to take current limiting measures (such as can be used is the temperature coefficient of resistance, fuse, and pressure-sensitive resistor used in tandem). The working principle of the gas discharge tube can be simply summarized as gas discharge. When a large amount of power between the two levels, the gap between the pole will be placed on the electrical breakdown, then it is transformed into a conductive state by the insulation state, this phenomenon is similar to the short circuit. When in the conductive state, the voltage between the two poles will be lower, generally between 20 ~ 50V, therefore, it can play a good role in the protection of the circuit.
Gas discharge tube using ceramic sealed, the internal by two or a plurality of band gap of the metallic electrode, filled with an inert gas (argon or neon) constitute. When applied to the two extreme voltage reaches the gas discharge tube gas breakdown, the gas discharge tube began to discharge, and is composed of a high resistance becomes low resistivity, the electrodes at both ends of the voltage does not exceed the breakdown voltage.