looking for someone to build me a high frequency amp

[fasterstill]

HI Guys
New here so hope this is ok?
Im looking for someone to build me an amp to drive 4-8 piezos up to around 200w. frequency range 10-38khz.
Tryed doing it myself as im a computer enginner and thought it would be simple enougth but this is a whole different ball game.
Im in the UK so anyone over here would be better but shipping from anywhere is,nt the end of the world.
Any takers please email or PM me.
cheers for your time.

[Nordic]

Post in the solidstate thread, most of the power chips are frequency limited....

[tiltedhalo]

Whats the application, piezo element frequency impeadance and load requirements?
Chips are possible and probably the cost will be about the some as ST.

[fasterstill]

Told i should post here, origionaly posted in chip thread


HI Guys
New here so hope this is ok?
Im looking for someone to build me an amp to drive 4-8 piezos up to around 200w. frequency range 10-38khz.
Tryed doing it myself as im a computer enginner and thought it would be simple enougth but this is a whole different ball game.
Im in the UK so anyone over here would be better but shipping from anywhere is,nt the end of the world.
Any takers please email or PM me.
cheers for your time.

[fasterstill]

Thanks for the reply,

Its to be used on a farm for an anti pest and possible security system, Will have IR sensors set up to detect Foxs. I have a deal with the farmer that if i can stop the foxs he'll stop having them shot.
The piezos im looking to use are
Specifications:
Frequency range: 4kHz - 40kHz
Power: 150Wmax / 75Wrms
Impedance: 250 - 50Ù over operating range*
Pretty standard, also looking if nessersary to place the piezos into tubes and directing along the paths, won't know untill tested.
Loading will be ten mins on activation.
I have soursed a frequency generator that im looking to use and am hoping to drive an amp with this. If this is not possible having the Frequency Generator built at the same time on to the same board would be even better?
freq-gen
http://www.kemo-electronic.com/en/mo...071n/index.htm

Any input advice greatfully recived.

Cheers

[Duo]

hmm, interesting request. The last large power amplifier I built for myself has a power bandwidth extending to 444KHz at 500W per channel on 4 ohms....

[FastEddy]

"Specifications
500 Watts RMS into 4 Ohms RMS Min Continuos
300 Watts RMS into 8 Ohms RMS Min Continuos
Frequency Response: 5hz to 200khz
SIgnal to Noise Ratio -125db ..." from: http://aussieamplifiers.com/nx500ln.htm

"Specifications
+-56vdc Voltage Rails (Idle, No Signal)
146 Watts RMS into 8 Ohms
230 Watts RMS into 4 Ohms
+-63vdc Voltage Rails (Idle, No Signal)
185 Watts RMS into 8 Ohms
275 Watts RMS into 4 Ohms
Frequency Response: 2hz to 160khz (Input Filter Limited)
Power Bandwidth 2Hz - 500khz -3dB Filter Limited
THD Typically 0.005% @ 8 Ohms 1khz
Damping Factor 400
Input Impedance 34k Ohms
Input sensitivity for full power out into 8 Ohm load 900mv ..." From: http://aussieamplifiers.com/nx150.htm

[fasterstill]

Originally posted by Duo
hmm, interesting request. The last large power amplifier I built for myself has a power bandwidth extending to 444KHz at 500W per channel on 4 ohms....

444khz, why such a crazy high frequency, surley you can't get antthing to drive past 50khz and probably can't hear past 22khz anyway? Is this just over spec of components or is there a reason for building it to those specs?
Sorry if its a dumb question, im a comp eng by trade just a novice with audio.

[pinkmouse]

Threads merged.

[Conrad Hoffman]

Piezo transducers are typically capacitive, so amplifier design is problematic. Almost all the power is dissipated in the amp, not the transducer. Best bet is to resonate the transducer with a suitable inductor (suitable=troublesome-to-design) so the reactance mostly disappears and the amp just has to drive the remaining more-or-less non-reactive load. This only works at one frequency, so if you need to cover a range, a much more complicated and expensive solution will be needed. You can also do a power oscillator like an ultrasonic cleaner, in fact stealing the board out of one might be a good place to start.