OEM for this Lucas YWB208 automotive DMM please? - Page 1
Forum section: electronics / testgear

author: shakalnokturn
author_rank: Super Contributor
timestamp: October 01, 2019, 06:59:10 pm
content: Smells ISO-Tech like to me, anyone know better?How much would you pay for one in good condition?Thanks

author: totalnoob
author_rank: Regular Contributor
timestamp: October 02, 2019, 12:00:35 am
content: No help on OEM, but how many cylinders can it handle? I mean, most are 4 through 8 cyl. Been looking for a decent one that can handle checking the rpm on a small 1 or 2 cyl engine.

author: tautech
author_rank: Super Contributor
timestamp: October 02, 2019, 12:17:05 am
content: Quote from: totalnoob on October 02, 2019, 12:00:35 amSee this thread for some ideas:https://www.eevblog.com/forum/beginners/read-rpms-directly-from-dso-math-functions/Typically all single cylinder spark each revolution so we’d just halve the reading for a twin.If you can afford it go for a quality wireless tacho.

author: shakalnokturn
author_rank: Super Contributor
timestamp: October 02, 2019, 02:18:40 am
content: Quote from: totalnoob on October 02, 2019, 12:00:35 amGoing O.T. to mechanics, correct me if I'm wrong I've done less mechanics than electronics: 4 stroke engine no matter number of cylinders, looking at a single cylinder 0.5 ignitions/revolution. 2 stroke engine no matter number of cylinders, looking at a single cylinder 1 ignition/revolution.The quick way is to monitor the TDC sensor where you usually have 1 pulse/revolution.Why would you want a multimeter to handle 2,3,4,5,6,8,12 cylinders? If you're into solving timing problems the minimum you want is an oscilloscope.

author: tautech
author_rank: Super Contributor
timestamp: October 02, 2019, 02:33:06 am
content: Quote from: shakalnokturn on October 02, 2019, 02:18:40 amSo you might think but no, they spark each revolution as the flywheel magnets pass the ignition coils.Even single cylinder with a typical 12V ignition coil the points open each revolution.

author: cs.dk
author_rank: Unknown
timestamp: October 02, 2019, 04:13:10 am
content: Lucas - "The inventor of darkness"Why would you see rpm on the meter? Not a very useful measurement.Cars have been using the wasted spark for ages. How ever, many seems to switch to coil on plug, which only fires when necessary.

author: Whales
author_rank: Super Contributor
timestamp: October 02, 2019, 05:41:57 am
content: Quote from: cs.dk on October 02, 2019, 04:13:10 amTuning idle speed on carby.

author: totalnoob
author_rank: Regular Contributor
timestamp: October 03, 2019, 11:54:53 am
content: Quote from: Whales on October 02, 2019, 05:41:57 amThis. And the point about a wasted spark is true, which is why a multimeter that takes that into account is a better option when all you need is the rpm, vs calculating it from the frequency. I have a contact tachometer that I can easily use on a "lawnmower" engine on the bench, but if I'm working on a motorcycle, scooter, moped or any engine on a "vehicle" I may not have easy access to the crankshaft even for a non-contact tachometer. Ironically, I have no use for an automotive multimeter for working on cars, mainly off-road equipment (hence why I put quotes on "vehicle"), so the higher cyl. ranges are not needed. I don't want to have to disassemble my'81 Honda Passport scooter engine, for example, just to measure what the rpm is, and no it does not already have a built-in tach, all it has is a speedo.Edit to add: All due apologies to the OP, I did not mean for this to take your thread on a tangent. I was hoping you had the specs and if you knew what the minimum # of cylinders is for this meter. BTW, I cannot find this meter anywhere, even a website that purports to be Lucas's.