How can I improve this scheme to reduce consumption? MOSFET is 4N0403
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\$\begingroup\$ What are your load and all loss incl L loss (DCR) specs? \$\endgroup\$– D.A.S.Commented May 2, 2022 at 18:49
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\$\begingroup\$ I don't understand the question, I'm a beginner. Out i need 3v 100 mA. \$\endgroup\$– MiauCommented May 2, 2022 at 19:04
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\$\begingroup\$ Have you read how to switch DC to DC circuits yet? There are a lot of problems with 16A 90% duty cycle in DCM drawing hundreds of watts to create 0.3 W. Specs mean Max inrush current, Peak input power, output power , load regulation error. \$\endgroup\$– D.A.S.Commented May 2, 2022 at 19:22
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2\$\begingroup\$ First thing that comes to mind is don't use a 555, use something with feedback. LT and Maxim have some pretty good flyback controllers. \$\endgroup\$– HearthCommented May 2, 2022 at 19:30
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\$\begingroup\$ You cannot design anything without detailed specs. What are they? \$\endgroup\$– D.A.S.Commented May 2, 2022 at 19:41
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1 Answer
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Remove the NE555, it's easily accounting for 10% of power consumption already; on top of many other reasons it's unsuitable. (If you must, 555s can be used as a switchmode controller, with a lot of help; but it's still rather inferior to a proper one. It's also maybe not the best building block for learning, if you're looking to construct the inner workings of better-known controllers like say UC3843. Which, whether doing so with logic, discretes or 555s -- is an exercise I do recommend!)
Offhand, CS5171 or friends might be suitable here, albeit rated much more current than you're looking for. Better options can be found in a supplier search.
answered May 2, 2022 at 21:13
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\$\begingroup\$ I use TL555i (low power consumption cmos version). It is impossible for me to believe that a circuit consisting of two transistors (Royer Oscillator) can be used for a low power converter, and the IC 555 is rejected by everyone. This circuit is easy to find and in 10 years, the dedicated circuits will not be found and in a few years they will not be produced. \$\endgroup\$– MiauCommented May 3, 2022 at 4:10
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\$\begingroup\$ the 555 is simply not the type of device you need, Miau. End of story. \$\endgroup\$ Commented May 30, 2022 at 11:02