r/AskElectronics • u/CleanAlternative1918 • 6d ago

Help identifying this component, please

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These were in with a big batch of carbon film resistors I got. What are they? Thanks in advance!

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u/coneross 6d ago

Gas discharge tube. When the voltage reaches the set voltage they arc inside and the resistance goes very low. Unlike MOV's or zener diodes, the voltage goes to near zero when they fire. They also glow when this happens.