I found a component designated RY8015 which I don't recognize, shown on the photo below on an LCD TV PCB (the bulb-like part next to a green radial varistor).

What is it called? What is its design function?

image of the PCB with the part in question

  • \$\begingroup\$ Looks like a regular neon bulb, probably for overvoltage protection. \$\endgroup\$
    – jippie
    Mar 6, 2016 at 16:35
  • \$\begingroup\$ It's a neon; they're used for a few different things. Usually it's some form of voltage control, either clipping overvoltage, or triggering & discharging in an RC sawtooth oscillator circuit. \$\endgroup\$ Mar 6, 2016 at 21:58

1 Answer 1


It is a discharge tube, possibly neon filled.... Normally it remains as open circuit, but if some part of the circuit received or generated higher than nominal voltage, the discharge tube fires and the resultant current will serve as the input for the detection circuit so that the abnormal condition can corrected.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.