A
Alun
- Jan 1, 1970
- 0
Please be more specific, in your post you haven't stated what you want to replace with a 10W speaker, whether you're repairing a pest repeller or whether you want to make one.
A
Alun
- Jan 1, 1970
- 0
Then a tweeter is probably the best option for you.
What sort of pest repeller do you want?
Mouse?
Insect?
I believe you need different frequencies for different pests.
What sort of pest repeller do you want?
Mouse?
Insect?
I believe you need different frequencies for different pests.
audioguru2
- Apr 6, 2004
- 12,026
- Joined
- Apr 6, 2004
- Messages
- 12,026
Hi Walid,
A piezo transducer can operate at very high frequencies and has a high impedance.
Many speakers don't work at very high frequencies and are a low impedance.
Post the schematic of the pest repeller circuit so we can see if its output transistors will melt when trying to deliver a high current to a low impedance speaker.
Also post the spec's for the speaker so we can see if it works at high repeller frequencies. ;D
A piezo transducer can operate at very high frequencies and has a high impedance.
Many speakers don't work at very high frequencies and are a low impedance.
Post the schematic of the pest repeller circuit so we can see if its output transistors will melt when trying to deliver a high current to a low impedance speaker.
Also post the spec's for the speaker so we can see if it works at high repeller frequencies. ;D
A
Alun
- Jan 1, 1970
- 0
audioguru,
Doesn't this depend on the frequency?
Moving coil speakers are inductive, this means thier impedance increases with frequency and piezos are capacitive meaning their impedance decreases with frequency. At some point the impedance of say an 8ohm tweeter will become higher than a piezo speaker.
Doesn't this depend on the frequency?
Moving coil speakers are inductive, this means thier impedance increases with frequency and piezos are capacitive meaning their impedance decreases with frequency. At some point the impedance of say an 8ohm tweeter will become higher than a piezo speaker.
Last edited:
audioguru2
- Apr 6, 2004
- 12,026
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- Apr 6, 2004
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Hi Alun,
An 8 ohm tweeter will be about 25 ohms at 30kHz. I don't know the capacitance of a piezo but I don't think it is as low as only 25 ohms (0.2uF). ;D
An 8 ohm tweeter will be about 25 ohms at 30kHz. I don't know the capacitance of a piezo but I don't think it is as low as only 25 ohms (0.2uF). ;D
Hi all of you, her is the circuit from:
http://www.zen22142.zen.co.uk/Circuits/Misc/insecrep.html
you must know that if i go to any part supplier and ask for 3.25" piezo, they will not understand what i want, i depend on scrap board to get my parts, may i have one piezo somewhere but i can't identify it, so it is better idea to see this great piezo.
for audioguru i have many speakers from distorted radio-cassette, tvs and telephones, the only data i know is the dc ohm and power rating like 8 ohm, 0.25W.
thank you all.
View attachment 37398
http://www.zen22142.zen.co.uk/Circuits/Misc/insecrep.html
you must know that if i go to any part supplier and ask for 3.25" piezo, they will not understand what i want, i depend on scrap board to get my parts, may i have one piezo somewhere but i can't identify it, so it is better idea to see this great piezo.
for audioguru i have many speakers from distorted radio-cassette, tvs and telephones, the only data i know is the dc ohm and power rating like 8 ohm, 0.25W.
thank you all.
View attachment 37398
audioguru2
- Apr 6, 2004
- 12,026
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- Apr 6, 2004
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- 12,026
Hi Walid,
An 8 ohm 0.25W speaker and the transistors will blow up in that circuit. An ordinary speaker won't reproduce very high frequencies anyway.
Motorola's piezo tweeter was used in many cheap big speakers for guitars and stuff.
Search for Motorola Piezo Tweeter in Google for places selling them. I think they are obsolete so there are limited quantities available. It looks like this:
View attachment 37400
An 8 ohm 0.25W speaker and the transistors will blow up in that circuit. An ordinary speaker won't reproduce very high frequencies anyway.
Motorola's piezo tweeter was used in many cheap big speakers for guitars and stuff.
Search for Motorola Piezo Tweeter in Google for places selling them. I think they are obsolete so there are limited quantities available. It looks like this:
View attachment 37400
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