Sujet : Re: Another design
De : invalid (at) *nospam* invalid.invalid (Edward Rawde)
Groupes : sci.electronics.designDate : 10. May 2024, 20:57:03
Autres entêtes
Organisation : BWH Usenet Archive (https://usenet.blueworldhosting.com)
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"piglet" <
erichpwagner@hotmail.com> wrote in message
news:v1li00$1eir3$1@dont-email.me...On 10/05/2024 4:11 am, Edward Rawde wrote:
"Edward Rawde" <invalid@invalid.invalid> wrote in message
news:v1ho21$4ps$1@nnrp.usenet.blueworldhosting.com...
Now with 9V to 15V input range, direct gate drive and 500mA LED current.
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Startup behaviour is not ideal but maybe that can be fixed if it needs
fixing.
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What's the cheapest op amp I can use for U2 instead of OP07?
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Is there a cheaper comparator instead of LT1719 which will work?
Also the fet is bigger than it needs to ne.
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Is there a better device for D4? Particularly if R4 can be reduced.
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Will it work at all? Except in simulation.
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I think I've answered my own question for the current controller but I
don't
think it's feasible to attempt a discrete comparator on cost grounds.
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...
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The venerable LM311 is still a good value comparator, if you want to penny
pinch omit the gate driver buffers and lower the pullup resistor but
efficiency will drop a lot from 85% to ca 72%.
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Thanks, that works but I was hoping for a smaller inductor at about 1MHz and
filtered LED feed referenced to ground for up to three LEDs.
I'm probably done with my circuit unless there's a cheaper comparator which
can do the same job or a cheaper op amp which can run on lead acid voltage.
Or preferably up to 15V.
Also a cheaper fet.