Hi everybody,

I am a scientist and i work on photosynthesis. In the laboratory we own a large collection of light bulb.
Here is some of them (with a post-it to have an idea of the size)... Could you tell me some informations about that (date,...)?

1) OSRAM 54.4786 D 1000w 220v :
This bulb was used on landing place. In my laboratory, it was used for photoinhibition of photosynthetic organisms (that means exposure to too much light). It heats so much that it has to be cooled or it burns... It is very big!



2) What is it?
This bulb was recovered from an old laboratory. It is full of mercury... There is no information on the bulb. I think is was "hand-made"...




3) H30S quartzbrenner Carl Zeiss.
Probably a spectrophotometer bulb.



4) Mazda 115v 300w
Purchased on a flea market...


I have many others if you are interested...
Best regards and... Happy new year!!!

You may have a very old Mercury solenoid switch. These are very rare and difficult to find. I would hang on to it or donate to a electrical equipment museum.

Great pictures.
Thanks.

BTW up until recently these were still made for special applications, but the Mercury hazard problem has kind of put a stop to them.
The idea of using Mercury is that they are not prone to contact wear or chatter like a normal relay can be.
They are position sensitive but are adjustable as to the pull in point.
Normal relays are just on and off and not adjustable.
Sometimes these are used to switch the output of photocells or other variable voltage device like a thermocouple.
Or to say, a analog input to a digital output at a set point.
  
There are now solid state devices that work the same.
But they are not fun to watch, they just sit there and work.
Solid state devices, kind of dull to watch.