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What are these parts called?

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gary350

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I have found these in old TVs and old Microwave ovens. I thought maybe they might be buzzers or speakers?

I connected a 555 timer to one of these to see if it would buzz but it clicked 1 time. It would never click again.

I connected a 1.5 vdc AAA battery to one it clicked too. It would never click again.

I think I killed 2 of these.

**broken link removed**
 
In that plastic housing, it looks like they are being used as sounders. They can be used as sensors, sounders, actuators etc. Google is your friend...look up piezoelectricity and go from there :)
 
It's a buzzer as you previously thought. The trick is to drive at the correct frequency so that it resonates in the plastic housing.
 
It clicks only one time because it is also a capacitor that charges then holds its charge. It should click again if you reverse the battery wires to it. When it is used as a transducer then it is fed AC that alternates its polarity.
Some piezo beepers have a transistor oscillator inside and a third feedback terminal on the piezo wafer. Then it oscillates at the loudest frequency.
 
I have found these in old TVs and old Microwave ovens. I thought maybe they might be buzzers or speakers?

They are piezo sounders - you find them in microwaves, NOT in TV's - they are what makes the beeping noises.

You also won't have killed them, they are pretty indestructible :D
 
I did see things similar to those in old TV sets, and they were Cadmium Sulphide photo resistors and were used to adjust the brightness of the picture depending on the amount of daylight in the room. They were a bit of a gimmick and fell out of use. Cadmium Sulphide fell out of use too, and photo sensor devices were based on silicon photo diodes.
 
I did see things similar to those in old TV sets, and they were Cadmium Sulphide photo resistors and were used to adjust the brightness of the picture depending on the amount of daylight in the room. They were a bit of a gimmick and fell out of use. Cadmium Sulphide fell out of use too, and photo sensor devices were based on silicon photo diodes.

I don't think they ever looked anything like that :D (and I've seen plenty of them over the years - just as I've seen a great many of these sounders in microwaves).

It's a silly ideas which gets revamped every few years.

Many modern TV's still do something similar, you have to disable it during install of the sets - it was a stupid feature back in the 50's, and it's a stupid feature in the 2010's :D

Incidentally, on modern Sony sets it's called an 'ambient sensor'.
 
Cadmium is deadly. So Cadmium Sulfide light sensors and Ni-Cad batteries are not popular anymore.
 
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