Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design Subject: Re: CO2 Funny Date: Mon, 27 May 2024 15:05:14 +1000 Organization: A noiseless patient Spider Lines: 73 Message-ID: References: <044o4j5st4od6fca3lj3pgs9diccmrenjn@4ax.com> <2lep4j1lvsiathlf5mu1sov52fkppten50@4ax.com> <54np4j5eq0gga4u24i69i6sechie1ohcjd@4ax.com> <2k9s4j94256k6gbapd5snscqosn3b53ici@4ax.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Mon, 27 May 2024 07:05:17 +0200 (CEST) Injection-Info: dont-email.me; posting-host="aed20492508d01e9c7c0dbb44a658828"; logging-data="4094098"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19E+KIK6Bxnm6E1R/inI1t6Wk+4D8NHrD4=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:Fp8GhjEGWYZF6M57d6AK8Cnrim8= Content-Language: en-US In-Reply-To: Bytes: 5171 On 27/05/2024 4:22 am, Edward Rawde wrote: > "Bill Sloman" wrote in message news:v2uhs7$39s6m$1@dont-email.me... >> On 26/05/2024 4:38 am, Edward Rawde wrote: >>> "Bill Sloman" wrote in message news:v2na16$1nvei$1@dont-email.me... >>>> On 23/05/2024 3:52 am, john larkin wrote: >>>>> On Wed, 22 May 2024 18:10:58 +0100, Pomegranate Bastard wrote: >> It usually takes a while to work out why they did it that way, and it's pretty much essential to spend that time before you start >> fiddling with the circuit. That wasn't true of the guy who'd put in the 741. He was very much in the John Larkin "if it sort of >> works, ship it" camp. > > Which of John Larkin's products have you purchased and tested and what improvement > do you think should have been made before it was shipped? Absolutely none of them. The timing gear he sells to the American National Ignition Facility is based on a 1978 Hewlett Packard scheme, written up in their journal, and it depends on starting up a 50MHz free-running oscillator in a very predictable way. Faster oscillators have less jitter, and while synchronising to a continuously running faster oscillator twice may introduce extra jitter, the net jitter on the time delay can be quite a bit less. I had much the same problem in 1988 and went for a free-running 800MHz oscillator. It turns out that the first version of John's 50MHz oscillator had a nasty - if small - sub-harmonic oscillation and he's finally found a better version. >> Management liked him because he was quick. Production was less enthusiastic. > > Management likely expected that problems would be found which would have to be dealt with at a later time. I got to cleanup his mess ten years later, and only because some of the parts he had used had gone obsolete. It didn't mention another error - his 741 had to drive a few metres of shielded pair, which was a big enough capacitative load to make it oscillate, to which his solution had been to hang on a 100uF electrolytic, so the oscillation was at too low an amplitude to be visible. There's a standard solution for that - National Semiconductor Applications note AN-4 Fig.14. which he should have known about. I'd certainly had to deal with it more than ten years earlier > >> Would you be kind enough to give your opinion of John Larkin once per month instead of twice per day? > >> When he starts claiming to do electronic design once a month rather than twice a day. > > I still don't see why it matters so much when the two of you are in different countries and, correct me if I'm wrong, > you've never used or tested any of JL's products. One of his standard insults is to claim that his critics don't design stuff. > You can't deny that JL has a successful business. > Whether his business would be more successful if he adopted different design techniques is not something I wish to go into > because it simply doesn't matter to me. He's the electronic equivalent of a vanity publisher. He give people who can't design their own electronics, bespoke electronic solutions to the problems that they think they have. I did a bit of that at Nijmegen University in the Netherlands, and most of what I found myself doing was getting people to recognise that they had a standard problem for which they could buy a standard solution off the shelf. -- Bill Sloman, Sydney