What is this electronic component?

Piezo sounder is normally a brass disc but with a large, 50% of the area at least, ceramic disc mounted coaxially on top to which the second connection is made. A missing connection to such a device is not likely to stop the scales working.

I think we're going to need that picture!

That is how it looked.

Could they have been using a piezo sensor as a strain gauge?

or to BALANCE a similar one so that you sensed differential strain...that's not unusual where sensors are prone to reading e.g. temperature as well. ;-)

The Natural Philosopher wrote in news:m8tts3$288$1 @news.albasani.net:

Sorry if this appears twice but I can't see my earlier post. I have noticed it says "BUZ" on the circuit board. It has never made a sound and the instructions make no reference to a sound.

Just sounds like a piezo buzzer. Stick 6v across it and see if it squeaks. No other component will make such a sound.

A bare piezo sounder needs to be driven by audio frequency AC (just like a loud speaker). DC won't make any sound, except maybe a quiet crackle if you gently brush a wire against it making a poor contact.

Oh, I think that you lost the thread (IYSWIM) in "Furred up DHW pipe!.

That is strictly true - but most will have a built in oscillator so they work from DC. That sort will likely have some form of polarity indication like black and red leads.

Maybe it's the load cell that actually provides the weighing function of the scales.

In a way yes, I expect that the scales self activate when the they are stepped on and that vibration caused in the case and the component induces a voltage in it which is sensed by a low powered wake-up circuit, activating the main measuring circuits.

DerbyBorn pretended :

It was maybe being used as part of a cheap oscillator circuit, but I cannot think why.

It's a bare sounder - no integrated circuitry.

snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) wrote in news:m8ua57$jaq$ snipped-for-privacy@dont-email.me:

I am left wondering if it is a sounder and the configuration of the circuit for this particular model (Salter 9000) just doesn't use the sound facility?

If it is to detect movement to turn it on - then I think this is done via the load sensors as a tap on the top plate activates it.

Some scales have a separate battery, possibly rechargeable that can hold settings for older non flash memory, but itin that case the scales should have run with new batteries, so I cannot say. Are you sure its not mechanically connected to the scales like a strain gauge would be? Otherwise its odd that it came loose. Brian

Its definitely a piezo transducer, but what its diong in that cct I cant imagine. Someone please crosspost to sci.electronics.design

NT

/Someone please crosspost to sci.electronics.design /q

Jim K

Quote from the manual

"Tap the platform centre (vibration activates your scale) and remove your foot."

It's acting in reverse as a microphone detecting vibration? It may explain why repairing the open circuit connection got the scales working again