Path: ...!news.nobody.at!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design Subject: Re: fast discrete PHEMT one-shot Date: Fri, 17 May 2024 15:37:13 +1000 Organization: A noiseless patient Spider Lines: 69 Message-ID: References: <48na4j10neo6bru36kllgm3447dclcrfgg@4ax.com> <9qdc4jdovsm0rousj88ngtn2bj6env9l48@4ax.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Fri, 17 May 2024 07:37:25 +0200 (CEST) Injection-Info: dont-email.me; posting-host="f62cb937bafdd9aad6a022f4fcf8a07f"; logging-data="2152695"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18gWVMnJoVGnRr9iixBniAHDuit39TQIXk=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:Sriy0rPZg9Sj++XZFS2LxLg5e6A= In-Reply-To: <9qdc4jdovsm0rousj88ngtn2bj6env9l48@4ax.com> Content-Language: en-US Bytes: 3760 On 17/05/2024 2:46 am, John Larkin wrote: > On Fri, 17 May 2024 00:40:32 +1000, Bill Sloman > wrote: > >> On 16/05/2024 11:15 am, John Larkin wrote: >>> On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet >>> wrote: >>> >>>> John Larkin wrote: >>>>> >>>>> https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1 >>>>> >>>>> Regular monostables are terribly slow. This one has low prop delay and >>>>> high rep-rate, if the sim is to be believed. >>>>> >>>>> SAV541 is mostly specified as an RF part, but it's a dynamite switch. >>>>> >>>>> I can post a link to the files if anybody wants to play with this. All >>>>> my values are first guesses, no math involved, and it works! >>>>> >>>>> My SAV541 Spice model is a revision of Phil Hobbs' original. >>>>> Mini-Circuits is adamant that they will never provide Spice models, a >>>>> typical RF-bigot attitude. >>>>> >>>>> >>>> >>>> Yay! Eccles-Jordan ride again. >>> >>> 1918! >>> >>> I think that was a bistable. I don't know when the monostable was > invented. >> >> https://en.wikipedia.org/wiki/Multivibrator >> >> has a two quotes from 1942 one from 1943 and two from 1949 which make it >> clear that monostable had been invented by then. It sees it as a cut >> down bistable, so Eccles-Jordan is probably a good name. >> >> Since the first multivibrator circuit, the astable multivibrator >> oscillator, was invented by Henri Abraham and Eugene Bloch during World >> War I, it probably isn't the right name. >> >> https://apps.dtic.mil/sti/tr/pdf/AD0410225.pdf >> >> is a 1963 Ph.D. on the bistable circuit. >> >>> People tend to roll eyes when I use one-shots in logic designs. I >>> can't see why. >> >> You can't trigger a one-shot immediately after it has been triggered, >> and the pulse width you get can be reduced if you re-trigger it too soon >> after it has generated it's pulse, when it hasn't entirely recovered. > > The SN74123 retriggerable one-shot, and a Fairchild equivalent, are > over 50 years old. But you don't get a new pulse when you retrigger a retriggerable monostable - you just stretch the one you had already started. > And "it's" is not the possessive form. It's means "it is." I do know that but produce the mistake as a typo from time to time, as you are well aware. And you've snipped the rest of my post, without marking the snip. -- Bill Sloman, Sydney