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HP Forum Archive 19

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Piezoelectric transducers and the 41C
Message #1 Posted by Geoff Quickfall on 13 July 2009, 12:56 p.m.

Does anyone know the electrical specifications the HP-41C piezoelectric tansducer requires. I have 3 CXs that need new ones due to some hackers soldering attempts, not me ;-)

Also looking for a supplier in North America, perferably Canada. I did find what I was looking for on the web in the UK but I don't know the voltage requirement.

link to piezoelectric transducers in UK 

Version one at the above site

Specifications:  
Piezo Transducer 27mm/18kHz  
Resonant frequency: 18kHz ±05kHz  
Impedance at resonance: 800Ù  
Capacitance: 25nF ±30%  
Maximum input voltage: 30V p-p  
Operating temperature: -20C to +70C

Version two also at the above site

Piezo Transducer 27mm/42kHz  
Resonant frequency: 42kHz ±05kHz  
Impedance at resonance: 500Ù  
Capacitance: 14nF ±30%  
Maximum input voltage: 30V p-p  
Operating temperature: -20C to +70C

The original transducer is 27mm and appear identical but of course appearances can be decieving!

Cheers, Geoff

Edited: 13 July 2009, 1:02 p.m.

      
Re: Piezoelectric transducers and the 41C
Message #2 Posted by Randy on 13 July 2009, 2:12 p.m.,
in response to message #1 by Geoff Quickfall

I have no idea what the specs are but I do have a boxful of them on hand. Shoot me an email with your postal address and you'll have some old fashioned mail :)

            
Email sent in trade for snail mail ;-)
Message #3 Posted by Geoff Quickfall on 13 July 2009, 6:32 p.m.,
in response to message #2 by Randy

Thanks!

      
Re: Piezoelectric transducers and the 41C
Message #4 Posted by Garth Wilson on 13 July 2009, 8:09 p.m.,
in response to message #1 by Geoff Quickfall

see the thread at http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv019.cgi?read=147367

Edit: BTW, your resonant frequencies are missing a decimal point. They should be in the range of a few kHz, not a few tens of kHz (which would be ultrasonic).

Edited: 13 July 2009, 8:12 p.m.

            
Re: Piezoelectric transducers and the 41C
Message #5 Posted by Geoff Quickfall on 14 July 2009, 3:57 a.m.,
in response to message #4 by Garth Wilson

Excellent thread Garth,

Learnt a lot more then just about the transducer. The decimal point came from the web site advertising, OOPS on them!

Cheers, Geoff

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