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Before transistors were available, what tubes/valves were used for driving incandescent lamps?
In the early days of computers, there were of course no transistors.
There was at least one type of tube that was specifically designed to drive regular incandescent lamps.
I suspect there were actually several types available.
The one I really want to know about was used in a homemade color organ that was either a one-off or a project built from a magazine article.
Many online searches have failed to turn up the type of which I personally saw and handled three samples, so I Will Not accept responses saying that there was no such thing.
It was, in fact, listed in one tube manual
that later disappeared --- and it was the Only one found with the listing.
I think it was a 5000 series or 7000 series 4-digit type number.
Lee26loo, you got it wrong AGAIN.
You DO NOT know enough to be answering such questions.
For one thing, the 12AX7 can't handle enough power to drive a 120 volt, 60 watt load!
The tubes I am asking about are large with an octal or similar-sized base
and either ST or GT glass envelopes --- they are Not 9-pin miniatures.
Lee26loo, you got it wrong AGAIN.
You DO NOT know enough to be answering such questions.
For one thing, the 12AX7 can't handle enough power to drive a 120 volt, 60 watt load!
The tubes I am asking about are large with an octal or similar-sized base
and either ST or GT glass envelopes --- they are Not 9-pin miniatures.
The answers provided are inadequate because the answerers are less informed than I am.
I really hoped someone out there would at least understand
that I know Precisely what I'm asking for,
just not the exact type number.
No best answer will be awarded on this one!
2 Answers
- daniel gLv 74 years ago
Incandescent lamps never were directly controlled by tubes to my know, and I cut my teeth on tubes.
Relays were the norm, but today, power mosfets work well.
Semiconductors and transistors were brand new technology when I started in electronics.
About your color organ, you might search older popular electronic magazines, but consider, even a 6L6 can only handle a 50 watt load in such application. Not many tubes functioned at 150 volts and capable of much current at all.
- ?Lv 74 years ago
In the old day like before 1950, complex relays set up system was the parts to do simple logic circuit to drive small power lamp as the logic indicator. But relay is too slow to be used to build high speed electrical calculator ( computer was not yet invent ). Electronic tube was used to take over relay logic circuit because tube is super fast compare to mechanical relay, common used is triode like 12AX7.
