Path: ...!news.mixmin.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design Subject: Re: P-channel MOSFET model Date: Thu, 9 May 2024 18:07:29 +1000 Organization: A noiseless patient Spider Lines: 182 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Thu, 09 May 2024 10:07:41 +0200 (CEST) Injection-Info: dont-email.me; posting-host="0e16e761979c96c99a29a5daa13376f2"; logging-data="587983"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/RwpkobRu65r9JLg//ZEYSQ7tKBNMPsLU=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:mgioY1aZnVdZiPjo3t+tSH1P/tY= Content-Language: en-US In-Reply-To: Bytes: 6194 On 9/05/2024 6:13 am, piglet wrote: > Bill Sloman wrote: >> On 8/05/2024 10:03 pm, piglet wrote: >>> On 06/05/2024 06:58, Edward Rawde wrote: >>>> "John Larkin" wrote in message >>>> news:aesf3j1po3glh1c23se3lofoni6j7ol75m@4ax.com... >>>>> On Sun, 5 May 2024 14:42:30 -0400, "Edward Rawde" wrote: >>>>>> "Edward Rawde" wrote in message >>>>>> news:v16s2i$2uv4$1@nnrp.usenet.blueworldhosting.com... >>>>>>> Does anyone know of a P-channel MOSFET, roughly equivalent to >> >> >> >> Cutting and pasting piglet's .asc file into my version of LTSpice gave a >> circuit that didn't do anything useful. M1 turns off after 2.67usec., >> and that's it. >> > > Damn! You are right, some thing strange happened with L1 value. The mu > symbol comes out wrong on a second system. Either retype as 220u or as > 0.22m and see if that works better? Switching to 220u did solve the problem. I should have noticed. Radiating 150kHz from a remote lamp isn't great idea. This variation on the circuit slows the switching to 16kHz, but doesn't do anything for the amplitude. Some gain along the feedback path would cut the reduce the current excursions through D2 and the radiated noise. Replacing Q2 with an LM358 might do it. Version 4 SHEET 1 1340 680 WIRE 64 -112 -144 -112 WIRE 256 -112 64 -112 WIRE 496 -112 256 -112 WIRE 1008 -112 496 -112 WIRE 1008 -96 1008 -112 WIRE 64 -32 64 -112 WIRE 1008 16 1008 -16 WIRE 1008 16 128 16 WIRE 256 64 256 -112 WIRE 64 96 64 64 WIRE 496 96 496 -112 WIRE 1008 96 1008 16 WIRE -144 144 -144 -112 WIRE 64 192 64 176 WIRE 128 192 64 192 WIRE 496 192 496 160 WIRE 496 192 208 192 WIRE 496 224 496 192 WIRE 544 224 496 224 WIRE 656 224 624 224 WIRE 736 224 720 224 WIRE 752 224 736 224 WIRE 864 224 816 224 WIRE 880 224 864 224 WIRE 1008 224 1008 160 WIRE 1008 224 944 224 WIRE 496 240 496 224 WIRE 256 320 256 144 WIRE 448 320 256 320 WIRE 736 320 736 224 WIRE 864 320 864 224 WIRE 1008 320 1008 224 WIRE 256 336 256 320 WIRE 64 384 64 192 WIRE 192 384 64 384 WIRE 64 400 64 384 WIRE -144 496 -144 224 WIRE 64 496 64 480 WIRE 64 496 -144 496 WIRE 256 496 256 432 WIRE 256 496 64 496 WIRE 496 496 496 336 WIRE 496 496 256 496 WIRE 736 496 736 384 WIRE 736 496 496 496 WIRE 864 496 864 384 WIRE 864 496 736 496 WIRE 1008 496 1008 384 WIRE 1008 496 864 496 WIRE -144 560 -144 496 FLAG -144 560 0 SYMBOL voltage -144 128 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 12 SYMBOL nmos 448 240 R0 SYMATTR InstName M1 SYMATTR Value FDS6612A SYMBOL schottky 512 160 R180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D1 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL ind 640 208 R90 WINDOW 0 5 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName L1 SYMATTR Value 220µ SYMATTR SpiceLine Cpar=1p SYMBOL LED 992 96 R0 SYMATTR InstName D2 SYMATTR Value LXK2-PW14 SYMATTR Description Diode SYMATTR Type diode SYMBOL res 1008 -64 R0 SYMATTR InstName R5 SYMATTR Value 1.2 SYMBOL res 256 96 R0 SYMATTR InstName R4 SYMATTR Value 3k SYMBOL pnp 128 64 R180 SYMATTR InstName Q1 SYMATTR Value 2N3906 SYMBOL res 64 432 R0 SYMATTR InstName R2 SYMATTR Value 3k SYMBOL res 176 192 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 62k SYMBOL npn 192 336 R0 SYMATTR InstName Q2 SYMATTR Value 2N3904 SYMBOL res 64 128 R0 SYMATTR InstName R1 SYMATTR Value 3k SYMBOL FerriteBead 688 224 R90 WINDOW 0 -16 0 VBottom 2 SYMATTR InstName L2 SYMATTR Value 14µ SYMATTR SpiceLine Ipk=3 Rser=0.0122 Rpar=870 Cpar=1000f SYMBOL polcap 992 320 R0 WINDOW 3 24 56 Left 2 SYMATTR InstName C1 SYMATTR Value 22µ SYMATTR Description Capacitor SYMATTR Type cap SYMATTR SpiceLine V=16 Irms=0 Rser=1.6 Lser=0 mfg="AVX" pn="TAJC226K016" type="Tantalum" SYMBOL FerriteBead 784 224 R90 WINDOW 0 -16 0 VBottom 2 SYMATTR InstName L3 SYMATTR Value 14µ SYMATTR SpiceLine Ipk=3 Rser=0.0122 Rpar=870 Cpar=1000f SYMBOL polcap 720 320 R0 WINDOW 3 24 56 Left 2 SYMATTR InstName C2 SYMATTR Value 22µ SYMATTR Description Capacitor SYMATTR Type cap SYMATTR SpiceLine V=16 Irms=0 Rser=1.6 Lser=0 mfg="AVX" pn="TAJC226K016" type="Tantalum" SYMBOL FerriteBead 912 224 R90 WINDOW 0 -16 0 VBottom 2 SYMATTR InstName L4 SYMATTR Value 14µ SYMATTR SpiceLine Ipk=3 Rser=0.0122 Rpar=870 Cpar=1000f SYMBOL polcap 848 320 R0 WINDOW 3 24 56 Left 2 SYMATTR InstName C3 SYMATTR Value 22µ SYMATTR Description Capacitor SYMATTR Type cap SYMATTR SpiceLine V=16 Irms=0 Rser=1.6 Lser=0 mfg="AVX" pn="TAJC226K016" type="Tantalum" TEXT 736 560 Left 2 !.tran 10m ========== REMAINDER OF ARTICLE TRUNCATED ==========