Tube-Based Boiler Controller / Thermostat?

[darrellcheng]

I work sometimes in building rehabs and I found what appears to be a tube driven thermostat for a boiler. I will take pictures and post it. I tried to google search something like it and have not found anything. Has anyone heard of or seen such a thing?

[Diablo]

There's a book in our library at work that describes all kinds of industrial circuits that use tubes. How about a tube amplified hearing aid?

[Jazz P Bass]

It really does depend on the tube type.
Thyratrons were used heavily for control circuits.
Relay control, timers, etc.

[J M Fahey]

Has anyone heard of or seen such a thing?

Of course, there was nothing else before the mid50's , and Industrial Electronics guys are pretty conservative, plus being big fans of "if not broke, don't fix it" so tube circuits may have been popular well into the 60's.
A friend of mine used to service Medical equipment in the 80's and was amazed to find stuff with *tubes* , *germanium* transistors and , obviously, more modern silicon transistors and ICs, all on the same machine.
They go 110% for the end result and don't care about how they get to it.
If it works the way they like ... it's valid.
Short ago somebody posted pictures of the Carillon (mechanical Church bell machine) he had to repair: it was a gorgeously built rack full of odd tubes.
US made, '61 vintage, still working save for some pitted relay contacts, go figure.

[Enzo]

Tubes? In a carillon? Foo.

We have a nice carillon here at Michigan Statue University. Totally mechanical, like god intended.