Gas discharge lamp structure
Gas discharge lamps come in various types, but they all share a similar basic structure. Each lamp consists of a glass bulb, two electrodes, and a specific type of gas inside. A vacuum seal connects the bulb to the electrodes, ensuring that the internal gas remains contained. These lamps cannot be directly connected to an electrical circuit because they require an external device, such as a ballast or a starter, to initiate and regulate the discharge process. When starting, gas discharge lamps typically need a higher voltage than the supply voltage—often several thousand volts or even more. This can be achieved using a step-up transformer or a starter. Once ignited, the arc discharge exhibits a negative volt-ampere characteristic, meaning that as current increases, the voltage across the lamp decreases. If no regulation is applied, this can lead to excessive current flow, potentially damaging the lamp or other components in the circuit. To prevent this, a ballast is used in series with the lamp. The ballast serves to limit the current and stabilize the operation of the lamp. Ballasts can take different forms depending on the power source. In DC systems, a resistor is commonly used as a ballast. For low-frequency AC sources, an inductor is preferred, while high-frequency AC systems often use a capacitor for ballasting. This ensures that the lamp operates safely and efficiently over time. Voltmeter,Digital Voltage Display,Digital Voltmeter Display,Ac Voltmeter Yuyao Gongyi Meter Co.,Ltd. , https://www.yycj.com