"Jon Elson" wrote in message
...
Madness wrote:

Just acquired a bunch of these lamps. They're in the same mini-bayonet
style as lamps like the #44/47. But would anyone know if these lamps can
be connected directly to 120 volts? Or do they need a resistor, @ if so,
what value?
Oh, you definitely need a series resistor. About 100K is typical.

Of 3 hits from searching NE51 - voltage rating was stated variously from
105 - 120.

Confusingly, one page displayed a picture of a filament bulb.

If a "bunch" of them is sufficient to sacrifice one, I'd peel the base cap
and see if there's a resistor in there.

Anything with a plastic lens cap probably has a resistor in the base.

Ionisation voltage is usually 70 - 90V, across the mains with a 100k
resistor in series would reveal the volt drop of the bulb - anything much
above 90V suggests an internal resistor.