Warning: mysqli::__construct(): (HY000/1203): User howardkn already has more than 'max_user_connections' active connections in D:\Inetpub\vhosts\howardknight.net\al.howardknight.net\includes\artfuncs.php on line 21
Failed to connect to MySQL: (1203) User howardkn already has more than 'max_user_connections' active connectionsPath: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: john larkin Newsgroups: sci.electronics.design Subject: Re: LTSpice model for a SiC MOSFET Date: Thu, 22 May 2025 07:36:28 -0700 Organization: A noiseless patient Spider Lines: 32 Message-ID: <16du2kd4qft7c0vanjgtesapq9krng00pf@4ax.com> References: <100c4og$t4lo$1@dont-email.me> <1rcl8ui.1xbo3q4bshnscN%liz@poppyrecords.invalid.invalid> <1dnm2k12d94ciunjpv2aavhb1v4peg9h60@4ax.com> <1rcqaf8.b7hc3i1j6cugoN%liz@poppyrecords.invalid.invalid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Injection-Date: Thu, 22 May 2025 16:36:31 +0200 (CEST) Injection-Info: dont-email.me; posting-host="d61e12f518d00827458561fb06f6a437"; logging-data="3696036"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19+YOKOeo3d2LJidLceeKDW" User-Agent: ForteAgent/8.00.32.1272 Cancel-Lock: sha1:T4dtRNH94S9OyFjbhWIANglDbog= Bytes: 2224 On Thu, 22 May 2025 09:44:30 +0100, liz@poppyrecords.invalid.invalid (Liz Tuddenham) wrote: >john larkin wrote: > >[...] >> Going from 1KV to 3.3v has interesting possibilities. The easy way is >> a resistor and a zener. Efficiency about 0.3%. > >Roughly 1W dissipation per mA , so if the current requirement isn't too >high, that is probably the most straightforward system with very little >to go wrong. > > >> More efficient would be a resistor and a zener and then a buck >> switcher. 5% maybe. > >That's a lot of extra complication for very little improvement, the >resistor still has to carry the full load current. > >For a cult market you could use an 807 and tap the 3.3v off the cathode >bias resistor. (or better still, rectify the heater supply and use a >linear regulator but don't tell the customer). I never liked 807's. Ugly tubes. https://www.dropbox.com/scl/fi/jaaw4dk4d4gm0api2h36r/833.jpg?rlkey=ajc90k4hw35lbwilfoph8qbmc&raw=1 Imagine a buck switcher with two HV npn's and one CCFL transformer as both the main inductor and the base driver.