Dan Michaels email (remove spam text)
Rich Ottosen wrote:
Thanks for the info. Gives me more to think about when I get to
breadboarding the ckt.
>One other thought. There was an article in Ciarcia Circuit Cellar
>Magazine some time back showing how to use a 40KHz IR receiver module
>for a ultrasonic transducer receiver by replacing the photodiode with
Hmmm, interesting idea. Sure would save on real estate. Double hmmm.
>No, the transducer will mechanically resonate all by itself. In fact,
>the higher the resistor value the higher the Q of the resonant circuit.
>The resonation (?) is started by the discharge of the transducer
>capacitance which causes the piezoelectric material to change in
>thickness. If you discharge at a rate that is at least as fast as the
>40KHz resonance, the transducer will be properly excited.
More to think about. This seems to go counter to the ckts shown in
"The Robot Builder's Bonanza" by Gordon McComb, upon which many
of the robo-hack-sonars on the web are based --> lots to play with.
thanks and best regards,
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