Another design

Edward Rawde · 2024-05-09T05:47:44+00:00

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.Version 4SHEET 1 2820 680WIRE 1312 -272 0 -272WIRE 1408 -208 288 -208WIRE 976 -144 160 -144WIRE 1088 -144 1040 -144WIRE -32 -48 -64 -48WIRE 0 -48 0 -272WIRE 0 -48 -32 -48WIRE 48 -48 0 -48WIRE 240 -48 48 -48WIRE 336 -48 240 -48WIRE 448 -48 336 -48WIRE 464 -48 448 -48WIRE 528 -48 464 -48WIRE 608 -48 528 -48WIRE 672 -48 608 -48WIRE 800 -48 768 -48WIRE 816 -48 800 -48WIRE 864 -48 816 -48WIRE 992 -48 944 -48WIRE 1024 -48 992 -48WIRE 1136 -48 1024 -48WIRE 240 -16 240 -48WIRE 336 -16 336 -48WIRE 1408 -16 1408 -208WIRE 1136 0 1136 -48WIRE -64 32 -64 -48WIRE 448 64 448 -48WIRE 464 64 464 -48WIRE 48 80 48 -48WIRE 160 80 160 -144WIRE 240 80 240 64WIRE 240 80 160 80WIRE 336 80 336 64WIRE 384 80 336 80WIRE 416 80 384 80WIRE 816 80 816 -48WIRE 992 80 992 -48WIRE 288 96 288 -208WIRE 336 96 336 80WIRE 336 96 288 96WIRE 656 96 480 96WIRE 688 96 688 0WIRE 688 96 656 96WIRE 240 112 240 80WIRE 384 112 240 112WIRE 416 112 384 112WIRE 528 112 528 -48WIRE 608 112 608 -48WIRE 1088 112 1088 -144WIRE 1136 112 1136 64WIRE 1136 112 1088 112WIRE 240 128 240 112WIRE 336 128 336 96WIRE -64 176 -64 112WIRE 1312 192 1312 -272WIRE 1136 208 1136 112WIRE 1200 208 1136 208WIRE 1280 208 1200 208WIRE 1392 224 1344 224WIRE 1408 224 1408 64WIRE 1408 224 1392 224WIRE 240 240 240 208WIRE 336 240 336 208WIRE 336 240 240 240WIRE 432 240 432 128WIRE 432 240 336 240WIRE 448 240 448 128WIRE 448 240 432 240WIRE 464 240 464 128WIRE 464 240 448 240WIRE 528 240 528 176WIRE 528 240 464 240WIRE 608 240 608 176WIRE 608 240 528 240WIRE 640 240 608 240WIRE 752 240 720 240WIRE 1184 240 752 240WIRE 1280...

Another design

May 09, 2024 Last reply: 2 years ago 22 Replies

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John Larkin 2 years ago

We have half-bridge switchers followed by multistage LC filters, and we take the loop-dominant AC feedback early in the filter, with slow DC feedback from local or remote sensed final output. If users want to trash their own transient response, let'em. The use loads could even be negative resistances.

There are self-tuning control systems that learn the overall loop dynamics and optimize the loop. Or there were; maybe it was a fad. But that would be a gigantic amount of software to try.

My favorite feed back loop starts at the mosfet switch node, before any filtering. The transfer function from PWM to switcher voltage is dimensionless +48 (ignoring the switching, of course.)

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Edward Rawde 2 years ago

Only one feed wire is needed in a three LED chain if grounded to metalwork. It's true that most things aren't done like that any more so I don't mind two wires if it can't be done any other way. Also two wires might radiate more than one wire, or might not depending on how they are filtered.

I already knew that most schematics were hideous messes when I read this.

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451 (pdf page 85) Perhaps I should have posted the circuit at the top of page 453 and asked for comments.

The project folder doesn't have subfolders?

Edit, simulate, edit ,simulate... encourages that. Just like compile, test, compile test... Today's world often doesn't allow time for the final design to have its layout cleaned up whether it's hardware or software. Time is money.

I'd put that in the spec. Must cope with any kind of bizzare load and remote sense connected to AC power line. Ok bizzare load might need further explanation.

Sounds fine to me but why put them in the conference room when remote desktop allows access from any computer in the building (or even outside the building if you know what you're doing with a firewall). I'm currently not at the location of the computer which will post this.

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Edward Rawde 2 years ago

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Thanks for circuit and the chip reference John. That meets my cost requirement. I always felt that spread spectrum for EMC was cheating but I'm aware that there are good arguments why it is not.

Also many thanks to piglet for taking time to post circuits.

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