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From: Winfield Hill
Subject: Re: Need real loud anti-dog barking ultrasonic device.
Date: 12 Dec 2002 13:08:29 -0800
Organization: Rowland Institute
References: <email@example.com> <3DF73938.2C99A7B4@cern.ch> <3DF88597.60AD3446@cern.ch>
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>Winfield Hill wrote:
>> Jeroen wrote...
>>> Winfield Hill wrote:
>>>> Very nice. I like the feature allowing a lower-voltage battery.
>>>> That reminds me, one ought to be able to use a dual MOSFET driver
>>>> IC to more easily make such a monster beeper,
> Win, Jeoen: In case I ever get around to building this, to replace my
> failed low-power design, could you clarify what those 4 inductors are
Sorry Terry, those aren't inductors, it's one transformer with
four windings. Or two center-tapped widings. It'd most likely
be custom wound on an ungapped pot core. And the resonating L
could also be made with a gapped pot-core. Along with the piezo
transducer, the transfomer design would be a non-trivial issue.
>. ___________|| ||______________________________
>. | ||___|| |
>. | #
>. | Vbatt (5 to 9V) L #
>. | ,--|<|--+-----o #
>. | | | |
>. | ============================================ |
>. | +---|(-- gnd |
>. | | | | |
>. | | R R TC4426 |
>. D /| | | |\ D
>. G--+-O< |--+ +--| >O-+--G
>. S | \| | | |/ | S
>. | | | \ / | |
>. gnd | gnd \/ | gnd
>. | C /\ C |
>. '-/\/-||-' '-||-/\/-'
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