"Steve Lusardi" wrote in
:

Larry,
You have my interest. I see these transducers shipped new in boxes,
open circuit, sitting on shelves. I never saw a high voltage warning
label on any of them. What is the recommended method to test a
transducer? Steve



Plug it into a sonar unit, put it in the water and see if you can see the
bottom in a hundred meters of water would be best.....

I was trying to test his transducer and cable out from the easy end to
get to without swimming in bilgewater. If the voltage rises from the
piezoelectric effect of the transducer listening to the noises in the
water, it's probably 99% just fine. If no DC ever shows up, cable or
transducer is bad, not the control head/transmitter/receiver....probably.
He didn't say he had a neighbor to swap units with to test it.

The tiny transducers on pleasure boats don't need a kill warning tag on
them. The transducers in a nuclear sub, to give you a perspective are
each about 20cm in diameter and 1.4 meters long. There are hundreds of
these in an electronically scanned array fore/aft/up/down/beamwise

It's no fun scrunched up in the sonar dome testing the damned things with
the test set, either....no air, hot as hell, cramped tiny space, no place
for your legs and feet. Been there....done that....it sucks.

What's fun is when the old transducers are sitting face down on a pallet
waiting disposal. Take a screwdriver and short them out quickly you get
a real impressive POP!....(c; "Hey! Why did you guys leave these things
ON?!", you ask the newbie who jumped.

The effect is the same as the spark igniter on a new gas grille. You
bang on the transducer, you get a high voltage spike from the
piezoelectric crystal. There's not much current unless the crystal is
huge and the circuit is very high impedance...high voltage.