08-24-2014, 10:42 PM
The voltage surge across the pilot light is not related to the filter caps. A larger value cap will increase the DC voltage from the power supply but not the filament voltage.
The reason the pilot lamp surges is because it is connected in series with the tube filaments. On first turn on, the resistance of the cold tube filaments is lower than when at operating temperature, so there is a surge of current as they warm up. Because the pilot light filament heats much faster than the tube filaments it flares brightly, and is subjected to overvoltage until the tube filaments are fully heated.
The reason the pilot lamp surges is because it is connected in series with the tube filaments. On first turn on, the resistance of the cold tube filaments is lower than when at operating temperature, so there is a surge of current as they warm up. Because the pilot light filament heats much faster than the tube filaments it flares brightly, and is subjected to overvoltage until the tube filaments are fully heated.
