I am building an ultrasonic transmitter using prowave 400fs080 .It offers 360 degree beam directivity . I have got the datasheet( http://www.datasheetlib.com/datasheet/1154043/400fs080_pro-wave-electronics.html ) of the transducer and it says that the maximum drive voltage is 150 vp-p for burst and the resonant frequency is 40khz. To produce such a signal ,I thought of using an opamp(741) multivibrator to produce the 40 khz square wave(Vpp - 24v) and connecting it to a primary of step up transformer(24v -120v).Will this work and what would be the current needed to drive the transducer.I cannot find the minimum or maximum current rating in the datasheet .how will the drive voltage and current affect the transmission .
No need for an opamp, you'd drive a resonant transformer with class C amplifier
(transistor in switch mode at 5 or 12V), thus avoiding most of the losses. That
means you have step-up transformer and resonant LC circuit in one, using the
piezo element as part of the tank capacitance.
This is standard RF design and without a background in that you'll struggle - you
probably have to experiment and wind your own transformers etc - not a simple
task and oscilloscope is mandatory.
The innards of a cheap chinese parking/reversing sensor off eBay contain 4
such circuits ripe for repurposing together with 4 transducers pre-tuned...
Would I be able to use this transformer? http://in.element14.com/prowave/k4000002/transformer-40khz-1-10-for400ep14d/dp/1774949?Ntt=PROWAVE+-+K4000002+-+TRANSFORMER%2C+40KHZ%2C+1%3A10%2C+FOR400EP14D .
The turns ratio is alone mentioned as 1:10.does that mean that any voltage can be given at primary and ten times the primary can be obtained at the secondary ?