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NEON NOVELTIES
A collection of circuits & info' using the neon lamp
Neon Lamp V-I curve (click to enlarge)
When used as a simple power on indicator, the neon needs about 0.2mA current, and show about 80 volt across its terminals.
Use formula below to calculate value of limiting (ballast) resistor.
Relaxation Oscillator
I believe so-called because the stored charge on the capacitor is "relaxed" once the neon lamp strikes at about 90 volt D.C.
Produces a Sawtooth type output voltage.
I used this type of circuit in the
Magic-Eye demonstration
to make the M-E's flick
Neon relaxation oscillator used for simple CRO timebase generator. (click to enlarge)
The flashing neon can be front-panel mounted
Indicates "power-on" before CRT warms up.
Square Wave Oscillator
The 1K/22K resistive divider and diode 'clamp' the max o/p at approx 5 volt.
"Ring" Oscillator

Ring oscillator driving incandescent lamps using SCR's
Lt Uhura comm's panel on "Starship Enterprise"
I always thought the erratic flashing light panels on Lt Uhura's console were made by a neon ring oscillator ?
As per circuit above.
Neon Voltmeter
Ex Australian Radio Television & Hobbies Mag Sept' 1964
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