Re: Unusual lamp bulb.

On 2024-08-07 01:12, peter@easthope.ca wrote:

Hi,
 Photo of the bulb and box here.  http://easthope.ca/Bulb25T6.5.jpg
 145 V, 25 W.

I googled. I found one reference to a DC max of 145.
https://www.vintage-radio.net/forum/showthread.php?t=98436
«I have seen 140/145 volt DC supplies, but in that case the 140/145 volts was the MAXIMUM not the nominal voltage.
Normally a 116 or 120 volt nominal lead acid battery charged by an engine driven dynamo. Lighting circuits would be supplied by a voltage regulator so as to give a roughly constant 115 volts on the lamps.
Power circuits direct from the battery and therefore up to about 140/145 volts when the engine was running.»
And this other:
«I can't throw any light on when or where 140VAC supplies were used, but 100 years ago, as GEC used to supply lamps for this sort of voltage.
In the GEC catalogue for 1911-12, while the most common voltage ranges for which lamps were supplied were 100-130V and 200 - 260V, certain types were available at pretty well any voltage. The customer was asked to specify the required voltage when ordering, hence the voltage ranges mentioned were ranges that were available and did not represent the range of voltages over which a particular type of lamp could be used. A range of 150-155V is specified for one particular type of lamp, suggesting that there was a demand for lamps of this particular type for use with a nominal 150V supply.»
--
Cheers, Carlos.