Checking Multimeter Calibration at Home
- Thread starter WheezyRider
- Start date
/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/filer/15/97/15972379-a704-4c12-8848-196d954896dc/42-55992923.jpg)
The clamp contains hall sensors for measurement, so I wondered how accurate it could possibly be. As for it's probes, unless I get an uprated BMS to power some high power device or other, my ebike battery is incapable of producing more than 20A. Three multimeters is one too many.
Last edited:
It depends on the hall sensor used. For e.g. Tektronix A622 current probe (as is suited for oscilloscope) uses hall sensor, in UK it might cost around £1000. There are hall sensor modules based on ACS712 that are not costly, reasonably accurate. And halls are often used in EV controllers where high voltage is involved (it provides isolation as compared to shunt)
Only £495 here, but used:
Genuine Tektronix A622 AC/DC Current Probe DC to 100kHz 50mA to 100A - Boxed | eBay
Genuine Tektronix A622 AC/DC Current Probe DC to 100kHz 50mA to 100A - Boxed as New Liquidation Stock In, boxed as new, secondhand condition and good working order Please click on the photos to see supersized images and to study the condition of the actual probe being sold Retailing at around...
www.ebay.co.uk
Inexpensive in terms of money, more expensive in terms of time pogramming the processing of signals, I imagine.
ACS712 ACS712ELC Current Sensor Module Hall Effect 5A 20A 30A 5V New UK Stock | eBay
ACS712 5A, 20A and 30A Current Sensor Module Options. On-board power indicator. Note Before you decide to Buy: This Module is provided with NO. We check and test each module, we are therefore unable. No Scotish Highland, Northern Ireland, Isle of Wight or other Isles.
www.ebay.co.uk
Weren't you working on a VESC controller project? How is that progressing? Have you given away too much equity in return for vulture capitalist funding yet?
Much better than Amazon's Black Friday offerings. AliExpress's Cyber Monday will be over soon enough.
Thank you @thelarkbox for your recommendation - I've ordered the Aneng "AAN8008/AN8009".
I also ordered this easy to read watch... it's because of the old eyes you know, £3 off. = £3.17+VAT. My Casio Databank and calculator+databank watches will have to be retired, the alphanumerics on their displays are too damned tiny and unreadable now, more than 30 years on.
SKMEI 1995 Luxury Digital Sport Watch for Men Women Waterproof Electronic Minimalism Design Girl Boy Wristwatches Reloj Hombre - AliExpress 1511
Smarter Shopping, Better Living! Aliexpress.com
vi.aliexpress.com
Last edited:
Youn twit! You could have got one of these, which are brilliant. You can make the face however you want, either by designing your own or downloading any of the 50,000,000 already designed. You can track all your bike rides and just about every aspect of your health. They're miles better than an Apple, Samsung or Fitbit watch. The battery lasts about 2 weeks before needing a re-charge. The others hardly last a day.I also ordered this easy to read watch... it's because of the old eyes you know, £3 off. = £3.17+VAT. My Casio Databank and calculator+databank watches will have to be retired, the alphanumerics on their displays are too damned tiny and unreadable now, more than 30 years on.
SKMEI 1995 Luxury Digital Sport Watch for Men Women Waterproof Electronic Minimalism Design Girl Boy Wristwatches Reloj Hombre - AliExpress 1511
Smarter Shopping, Better Living! Aliexpress.com
You can find it for much less if you use Google to search, but there are always the possibilities of fakes from Chinese suppliers.
Last edited:
If current needs to be known directly, then yes.Inexpensive in terms of money, more expensive in terms of time pogramming the processing of signals, I imagine.
ACS712 ACS712ELC Current Sensor Module Hall Effect 5A 20A 30A 5V New UK Stock | eBay
ACS712 5A, 20A and 30A Current Sensor Module Options. On-board power indicator. Note Before you decide to Buy: This Module is provided with NO. We check and test each module, we are therefore unable. No Scotish Highland, Northern Ireland, Isle of Wight or other Isles.www.ebay.co.uk
W/o any programming, I sometimes use it with oscilloscope (whenever current probe mentioned earlier is not available on loan at our incubator & when super accuracy is not required).
Feed 5V, 2.5V out signal corresponds to zero current & the current can be understood from signal seen on scope. It should be possible with multimeter as well, though some mental calculation would have to de done to deduce the current.
The project to create a controller that can provide motor assist according to the torque exerted by the rider without using torque sensor is making progress, though slightly delayed.
Initial iteration of the hardware is ready, basic FOC is working (to avoid licensing issues, had to do it independently of other projects, some portions of the code had to be written from scratch) on bench. Now in the process of setting up test system and adding the main product feature.
Note that it is not VESC or based on VESC, even the processor used is different. I had been involved with VESC even before this project & involved to some extent now too. Just that, earlier the proof of concept was developed using VESC by integrating my algorithm on top of VESC firmware, but it is not a derivative work of VESC.
Fully with me, the type of incorporation done prohibits issuing any shares.
Thank you for remembering my project
The trouble with those and the open source e-ink kits, is you have to remember to keep them charged. I'd need to set an alarm on a normal watch to remind me. It's crazy having to charge a watch every couple of days, or in the case of e-ink (not waterproof) open source, every week. I have quite enough devices which need charging every few days, my watch will never be one of them.
Last edited:
See what I mean? Compared to 2 years or more, that's rubbish. This e-ink watch would have been a contender, but it has no light, and it's CR2032 battery life isn't quoted.
56.44￡ 33% OFF|Berny Electronic Digital Watch For Men Fitness Ink Wristwatch 3atm Waterproof Men Sport Watch Stainless Steel Case Leather Strap - Digital Wristwatches - AliExpress
Smarter Shopping, Better Living! Aliexpress.com
vi.aliexpress.com
Last edited:
Yes but that one doesn't tell you when you have miocarditis or pericarditis from the vaccine. The Huawei might save your life.See what I mean? Compared to 2 years or more, that's rubbish. This e-ink watch would have been a contender, but it has no light, and battery life isn't quoted.
56.44￡ 33% OFF|Berny Electronic Digital Watch For Men Fitness Ink Wristwatch 3atm Waterproof Men Sport Watch Stainless Steel Case Leather Strap - Digital Wristwatches - AliExpress
Smarter Shopping, Better Living! Aliexpress.com
The Huawei measures your SPO2, checks and dispays your heartbeat 24 hrs a day, monitors your sleep, monitors your breathing while you're asleep, records all your bike journeys and tells you everything about them, counts your steps, counts the calories you burn, tracks and displays your stress levels, displays your SMS messages without your phone, vibrates and tells you when your phone is ringing, tells you the weather, tells you the air pressure. It has a compass in it and it works as a torch. It finds your phone for you and plays music through bluetooth earbuds or speakers. You can have whatever watchface takes your fancy and swap them when you want.
When I had bloodclots in my lungs, my Huawei watch showed me that something was wrong because it plots a graph of resting heartbeat, and mine had gone up significantly, which it had never done before. The doctor in the hospital wasn't very impressed when I went there to get fixed and I told him I know something is wrong because my watch says so. he was going to send me home with a stress diagnosis, until he saw the blood test results, which had markers for bloodclots off the scale.
I have this
Xiaomi Smart band 7 - Xiaomi UK https://www.mi.com/uk/product/xiaomi-smart-band-7/
£30 off ebay
Similar functionality, but need to pair with phone for GPS tracking (it does this automatically when choose outdoor cycling program)
Xiaomi Smart band 7 - Xiaomi UK https://www.mi.com/uk/product/xiaomi-smart-band-7/
£30 off ebay
Similar functionality, but need to pair with phone for GPS tracking (it does this automatically when choose outdoor cycling program)
They have the Mi Band 8 now for a few quid more that has a better display operation.
Thanks to Central Serous Retinopathy, the exact middle of my vision in both eyes is wonky. CSR is the new RSI for IT workers...
en.wikipedia.org
However, I've just now discovered when very bright light is shone on my existing watches, I can read the displays!
The key is having the very bright light close to hand... with your keys, so I grabbed one of these in the sales for £7.46. I hate having to take my phone out to read the time.
www.olightstore.uk
It amazes me that it's smaller than my many year old True Utility LaserLite, which is powered by three LR44 cells.
www.trueutility.com
The i3e-eos is very bright for such a small torch, much brighter than the LaserLite, and just the thing for illuminating dark paths while disguised as a pedestrian this time of year. That's me set, until these watches or my eyes cease functioning. 30+ years have taken a cosmetic toll on my watches, but they still work perfectly.
It's also bright enough to put muggers off for a brief period of time, probably. Pictured next to the AAA that powers it:
Heatshrunk, for it's paintwork to fare better than my True Utility LaserLite has... scratchy keys and loose change...
To make it easier to spot...
Central serous chorioretinopathy - Wikipedia
en.wikipedia.org
However, I've just now discovered when very bright light is shone on my existing watches, I can read the displays!
The key is having the very bright light close to hand... with your keys, so I grabbed one of these in the sales for £7.46. I hate having to take my phone out to read the time.
i3E EOS Smallest 90 Lumens Keychain Torch
i3E EOS Smallest 90 Lumens Keychain Torch
It amazes me that it's smaller than my many year old True Utility LaserLite, which is powered by three LR44 cells.
LaserLite
The LaserLite is a two function torch, combining a red laser beam with a powerful LED torch. Never be stuck in the dark again when equipped with this useful everyday carry. The laser beam a CE Certified beam, whilst the torch features an impressive 8+ lumen LED bulb. Designed to light any spaces...
www.trueutility.com
The i3e-eos is very bright for such a small torch, much brighter than the LaserLite, and just the thing for illuminating dark paths while disguised as a pedestrian this time of year. That's me set, until these watches or my eyes cease functioning. 30+ years have taken a cosmetic toll on my watches, but they still work perfectly.
It's also bright enough to put muggers off for a brief period of time, probably. Pictured next to the AAA that powers it:
Heatshrunk, for it's paintwork to fare better than my True Utility LaserLite has... scratchy keys and loose change...
To make it easier to spot...
Last edited:
According to my shiny new Neoteck, this cheapo 36V power supply, is more reasonably accurate than the unreasonably dead multimeter said it was.
Last edited:
It's great that your Huwaei didn't let your lungs get Huawei with it. My lungs are in pretty good shape - I slow jog for exercise. Did your lungs develop blood clots after getting jabbed with the vaccine? If so, perhaps there was lower level inflammation in your lungs which was exacerbated, perhaps due to fibreglass, or left over crud from smoke you've been exposed to in the past? If not, perhaps Covid greatly increased inflammation? Perhaps you were an early adopter? I'm pretty sure I was. Dunno, ask an actual quack, who may or may not know the answer - after getting jabbed with the AZ, that night I experienced a very intense fever which lasted 5 minutes, then it was gone. Then the following day I had a very bad headache all day, jolts of stabby agonising pain shot through my skull when my bike bounced over potholes. I had no reaction at all to the Pfizer booster.
I can well imagine smartwatches monitoring care home residents becoming more prevalent, as many are lost to the common cold this time of year especially. Presently, I simply need no-brainer reliable long term timekeeping to be the primary function of my watch, not an afterthought. A fair few smartphones don't actually function all that well as phones, not as well as mobile phones used to. I think it's a trend... everything's got to do everything everywhere.
I'm steering clear of Covid discussions, they can go a bit Pete Tong
Last edited:
No, I didn't get the vaccine because I already had the clots when they rolled it out. I was in extremely good shape at the time, as i regularly did 60 - 80 miles on my road bike, and it's very hilly here. A foot surgeon that was supposed to fix my broken big toe couldn't because of the state of my feet. He reckoned that between my blood clots and "covid toes", I probably had the alpha version of covid when I was a bit ill at the end of 2019, or maybe it was some other random virus that damages very small blood capillaries.It's great that your Huwaei didn't let your lungs get Huawei with it. My lungs are in pretty good shape - I slow jog for exercise. Did your lungs develop blood clots after getting jabbed with the vaccine? If so, perhaps there was lower level inflammation in your lungs which was exacerbated, perhaps due to fibreglass, or left over crud from smoke you've been exposed to in the past? If not, perhaps Covid greatly increased inflammation? Perhaps you were an early adopter? I'm pretty sure I was. Dunno, ask an actual quack, who may or may not know the answer - after getting jabbed with the AZ, that night I experienced a very intense fever which lasted 5 minutes, then it was gone. Then the following day I had a very bad headache all day, jolts of stabby agonising pain shot through my skull when my bike bounced over potholes. I had no reaction at all to the Pfizer booster.
I can well imagine smartwatches monitoring care home residents becoming more prevalent, as many are lost to the common cold this time of year especially. Presently, I simply need no-brainer reliable long term timekeeping to be the primary function of my watch, not an afterthought. A fair few smartphones don't actually function all that well as phones, not as well as mobile phones used to, I think it's a trend... everything's got to do everything everywhere.
I'm steering clear of Covid discussions, they can go a bit Pete Tong
Quacks discussed the possibility that gym bunnies ended up in ICU on breathing apparatus because regular exercise causes inflammation, as tissue is broken down by exercise and replaced, which was amplified when they contracted Covid. Quite surprising really. Fat tissue in obese people is also inflamed - before I lost three stones, my doc complained of my inflammation markers being very high. He insisted I take statins (they have to say that sort of thing when very high blood pressure and inflammation etc. is detected. Must be in the NHS handbook), I said "No, I'll lose weight". He was rather shocked that I did, and isn't going on about statins anymore. Bloody hard slog that was, and is. And it took about six months after I had lost two and a half stones, before my blood pressure reduced. I've still got to lose another 3/4 stone, and it's proving very stubborn.
I would be worried about how much of that data gets sent to China for Xi's purposes.