Hi All, 

I’m new here and a fraud as I don’t install security alarms but came across your forum when searching Radiovisor. I’ve just picked up from a house clearance sale two intriguing wall mounted Radiovisor devices that seem to use infrared and I wanted to try and find out their original application. I will try and attach pictures but they are both around 6” square and 4” deep, one having a single lens and one having twin lenses. They are badged “Radiovisor” and inside have the type BA500T. They appear to be from the 1930-40 era but bear no dates. Can anyone give me any clues as to where they would have been used and what for as I’m intrigued by them? They’re going on the wall in the utility room, come what may, but I’d like to find out about them if I possibly can! 
Thanks for any help you can give!

 

Paul King, Kent

They look like early IR beams transmitter and receiver. 

The would normally go across a large doorway or similar the modern version would look like below 

 

Radiovisor specialised in Active IR beams. Never seen any so old tho.

They work as a pair. Usually an IR beam is emitted then reflected back it detects if something blocks this.

1 hour ago, PaulKing said:

They appear to be from the 1930-40 era but bear no dates.

 

Looks 1970s to me ?

Thanks guys, those are helpful comments and confirm my thoughts although it’s useful to hear how they might have been used. When cleaning them yesterday I noticed that the single lense was red but the twin lenses are black, similar to welding goggles. I presume that the red would be the transmitter as there is a diode behind the internal curved lense? 

Mr Happy, what makes you think it might be 1970’s, is it the wiring colours or the style of the components?

11 hours ago, MrHappy said:

 

Looks 1970s to me ?

You looking in mirror on a good day? 😁 

Edited May 30, 20241 yr by al-yeti

The first production of an Led was 1962

The PCB material makes me think 70s. The capacitors maybe look more modern? It's probably hard to date if they would have been hand built and low batch numbers?