The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: Winfield Hill
Subject: Re: Need real loud anti-dog barking ultrasonic device.
Date: 14 Dec 2002 06:37:21 -0800
Organization: Rowland Institute
References: <firstname.lastname@example.org> <3DF73938.2C99A7B4@cern.ch> <3DF88597.60AD3446@cern.ch>
X-Newsreader: Direct Read News 4.20
> Terry wrote...
>>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 please?
> 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.
Terry, you should go back and look at the details in Jeroen
Belleman's 'gif drawing - http://cern.ch/jeroen/misc/BEEP.gif
He's already designed a transformer: each winding was 10 turns
on a bobbin with a RM8 pot core from 3B7 ferrite. He says the
FET / transformer / resonating-inductor combo can take 30W from
a small 6V NiCd battery, creating 400V across the transducer.
>>. ___________|| ||______________________________
>>. | ||___|| |
>>. | #
>>. | Vbatt (5 to 9V) L #
>>. | ,--|<|--+-----o #
>>. | | | |
>>. | ============================================ |
>>. | +---|(-- gnd |
>>. | | | | |
>>. | | R R TC4426 |
>>. D /| | | |\ D
>>. G--+-O< |--+ +--| >O-+--G
>>. S | \| | | |/ | S
>>. | | | \ / | |
>>. gnd | gnd \/ | gnd
>>. | C /\ C |
>>. '-/\/-||-' '-||-/\/-'
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup