...if you just need a loud 'beep', then you could run your piezos in a resonance circuit in order to derive 30Vrms out of 12V supply without smps converter...
...but take a little bit care. Some damping might be helpful to allows easier handling of the resonance.
And in any case take care about your piezo. I would not trust that every piezo can handle 30rms at high frequencies.... Ah well, the other way round. I would trust that such a signal beyond the continuous real life capability of most low cost piezos.
And in any case take care about your piezo. I would not trust that every piezo can handle 30rms at high frequencies.... Ah well, the other way round. I would trust that such a signal beyond the continuous real life capability of most low cost piezos.
The real Motorola piezos are the best, and they are only rated at 14V RMS above 4Khz.
If you're going to run a square wave you don't need an inverter from 12V, just a bridge output stage (car stereo chip).
If you're going to run a square wave you don't need an inverter from 12V, just a bridge output stage (car stereo chip).
...so 30Vrms seem to make no sense at all.
If one needs such power, then multiple piezos are needed. And if you use multiple piezos, you can parallel them and run with lower voltages.
djks proposal to bridge a car amp chip is sounding pretty reasonable and simple to me. If you use a class D chip, you can get outstanding efficiency and long battery times.
If one needs such power, then multiple piezos are needed. And if you use multiple piezos, you can parallel them and run with lower voltages.
djks proposal to bridge a car amp chip is sounding pretty reasonable and simple to me. If you use a class D chip, you can get outstanding efficiency and long battery times.
"If you use a class D chip, you can get outstanding efficiency and long battery times."
Please explain how a class D amplifier is any more efficient than a CFP bridge car stereo chip running a rail-to-rail squarewave.
I would use a Zetex siren driver chip.
Please explain how a class D amplifier is any more efficient than a CFP bridge car stereo chip running a rail-to-rail squarewave.
I would use a Zetex siren driver chip.
hi djk,
..I just missed that you proposed to run it full HIGH/LOW square wave.
I think thats perfectly fine.
Even better than real class D, if we consider switching losses of a real class D at several hundrets kHz.
...on the other hand we still do not know if fasterstill wants just a loud beep, or if he wants to chase his dangerous beasts by playing Black Sabbath backwards at 50times speed....
..I just missed that you proposed to run it full HIGH/LOW square wave.
I think thats perfectly fine.
Even better than real class D, if we consider switching losses of a real class D at several hundrets kHz.
...on the other hand we still do not know if fasterstill wants just a loud beep, or if he wants to chase his dangerous beasts by playing Black Sabbath backwards at 50times speed....
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