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From: "Edward Rawde" <invalid@invalid.invalid>
Newsgroups: sci.electronics.design
Subject: Re: Another design
Date: Thu, 9 May 2024 23:11:03 -0400
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"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.
>
> Startup behaviour is not ideal but maybe that can be fixed if it needs 
> fixing.
>
> What's the cheapest op amp I can use for U2 instead of OP07?
>
> Is there a cheaper comparator instead of LT1719 which will work?
> Also the fet is bigger than it needs to ne.
>
> Is there a better device for D4? Particularly if R4 can be reduced.
>
> Will it work at all? Except in simulation.
>

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.

Version 4
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WIRE 2032 -272 64 -272
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FLAG 1312 96 iref
FLAG 1328 448 ifb
FLAG 384 80 cmp-
FLAG 384 112 cmp+
FLAG 656 96 gate
FLAG 384 240 cmpv-
FLAG 1424 240 led
SYMBOL Comparators\\LT1719 448 32 R0
WINDOW 0 27 27 Left 2
WINDOW 3 -92 6 Left 2
SYMATTR InstName U1
SYMBOL res 320 112 R0
WINDOW 0 41 34 Left 2
WINDOW 3 35 64 Left 2
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