EEVblog #1263 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: November 20, 2019, 02:19:35 am
content: Mailbag time!SPOILERS:Automated Factory robot laser scanner teardownSiemens & Schneider Electric safety timer switch teardowns.18:54 HTC Vive VR Base Station Teardown37:35 40W 180V Nixie tube driver:https://www.tindie.com/products/nexus/40-watt-high-voltage-nixie-power-supply/https://neonkev.com/2019/10/15/success-201-boost-at-40-watts-without-a-transformer/45:07 Hadou-CAN USB CAN adapter:https://www.tindie.com/products/suburbanembedded/hadou-can-usb-can-fd-adapter/

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: November 20, 2019, 04:35:21 am
content: Great Scott Outback Dave , at 18:36 minutes you incorrectly called the IRF840 a transistor, it's actually a MOSFEThttps://components101.com/sites/default/files/component_datasheet/IRF840-Datasheet.pdf

author: maginnovision
author_rank: Super Contributor
timestamp: November 20, 2019, 05:22:43 am
content: metal–oxide–semiconductor field-effecttransistor

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: November 20, 2019, 05:41:00 am
content: Good call it may say it's a transistor, but it's does say "field-effect transistor" and acts more like a vacuum tube, then a straight dual P/N junction transistor that's either NPN or PNP I'm just defining the difference between the two even though they both either switch or do gainSort of like a Triode and a Pentode , both are " Vacuum tubes" , and they both either switch or do gain for amplification . But their functionality on how they operate internally is different due to how it's manufactured

author: FrankBuss
author_rank: Unknown
timestamp: November 20, 2019, 08:47:22 am
content: Found a nice video what the HTC Vive tracker does:Hereis an explanation how it works, includes the video as well. Accuracy is about 1.5 mm, and it even works with just one station (with less accuracy).I once tried a HTV Vive VR, and it is amazing how good the tracker is. But the headset was not very comfortable, and the field of view and display resolution not that great, and at least when I tried it, the image was only sharp in a small area, e.g. I couldn't read text when it was not in the center. Maybe needed some calibrations or adjustments. I tried a Microsoft Hololens as well, and it was much better, but much more expensive as well.

author: Pack34
author_rank: Frequent Contributor
timestamp: November 20, 2019, 10:38:06 am
content: @Dave,The serrations you noted in front of the image sensor on the scanner are called baffling. The purpose is to mitigate stray light issues. The image sensor does a good job absorbing the light, but light coming into the system can be off-axis and bounce off the sides. In general, this would reduce the SNR of your resulting image or create false images and ghosting. Another method to mitigate stray light is the finish and painting of the optical channel. This is one of the practical applications Vantablack.Related reading:https://www.newport.com/t/stray-light-in-monochromators-and-spectrographs

author: NivagSwerdna
author_rank: Super Contributor
timestamp: November 20, 2019, 04:09:05 pm
content: "Don't eat the desiccant" such wise words... I wonder if bigclive eats his?"Desiccants are the most common foreign object ingestion by children under 6 years of age"Sounds like the choking is the issue, so probably best to eat them in small pieces.

author: thinkfat
author_rank: Unknown
timestamp: November 20, 2019, 07:51:18 pm
content: I remember a huge thread here on the forum about development of a high voltage power supply for Nixies, was that the same guy? Must have been about half a year ago.

author: jonovid
author_rank: Super Contributor
timestamp: November 20, 2019, 09:36:01 pm
content: HTC Vive VR Base Station has what looks like two spinning laser linesthe corrugated or ripple laser lens on the side of rotating drum outputs a sweeping line.laser beam gos down the middle, axis of the drum. rotating cylinder & mirror.two spinning laser lines give you X & Y if your motor degrees of rotation is a know value.by timing your laser lines a 3D space is mapped out. robot eyesthe tools & Bitsquality hand tools gos next to quality test equipment.a must have. for my bench.

author: numloxx
author_rank: Contributor
timestamp: November 21, 2019, 12:20:38 am
content: Glad you got my postcard. They have so much stuff at the Heinz Nixdorf Museum in Paderborn. I spent the entire day there. Huge calculator collection as well.https://www.hnf.de/en/home.html- MuseumCalculator collection -https://twitter.com/numloxx/status/1171713415745888256Enjoy

author: station240
author_rank: Unknown
timestamp: November 21, 2019, 06:32:40 am
content: Those USB to CAN adapters are handy for debugging, or capturing traffic for reverse engineering.I should be doing more CAN stuff at the moment, but the last CAN device I bought of ebay isn't turning upSeems there are two versions of the Hadou, bare PCB and cased, so Dave actually has two of these.

author: Fungus
author_rank: Super Contributor
timestamp: November 21, 2019, 07:53:08 am
content: Quote from: johnlsenchak on November 20, 2019, 04:35:21 amDo you know what the 'T' stands for in "MOSFET"?

author: ETITsynthesizer
author_rank: Contributor
timestamp: November 21, 2019, 03:21:56 pm
content: Dave, when you said you didn't have a 40W resistor on hand that was a bit cringey for me. you have $10K in oscilloscopes but you don't have a $3 dummy load? I went on ebay. you can get a 300R and a 500R for $2.20 USD with free shipping. close enough to 810 Ohms to test that nixie driver. please do a part two.https://www.ebay.com/itm/25-50-100W-0-01-5k-Ohm-Watt-Shell-Power-Aluminum-Housed-Case-Wirewound-Resistor/152815608794at work we have a 600A dummy load built into a (stolen?) shopping cart. we don't have current sense shunts over 150A though. we do all the power supply calibrations at 150A or 140A. then we load test at up to 600A.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: November 21, 2019, 06:02:06 pm
content: Quote from: ETITsynthesizer on November 21, 2019, 03:21:56 pmI agree. That PSU claims 40W (although I don't know why you need to go that high, I am sure my small tube display draws 5W ish... Maybe big tubes need more). We want to see it cranked up to 11 with smoke coming out and some FLIR action.

author: FrankBuss
author_rank: Unknown
timestamp: November 21, 2019, 07:05:41 pm
content: Good idea with a short follow up video for the Nixie power supply. In the mailbag video, I expected that he would at least test the short circuit protection with a screwdriver or something, when he measured the voltage. Sometimes they are a bit optimistic with such claimsWould be a very useful device for me, someday I plan to finish myNixie clock. Price is a bit high, but if it meets the spec, and doesn't cause EMC problems etc., I would pay it.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 21, 2019, 07:42:12 pm
content: Quote from: NivagSwerdna on November 20, 2019, 04:09:05 pmApparently eating desiccant isn't an issue at all."Silica gel is chemically inert and is considered to be non-toxic. The concern with this substances it that it can be a choking hazard (this is why these packets often say ‘DO NOT EAT’ on them). If your child is choking on silica gel, call 911 immediately."

author: nexus
author_rank: Regular Contributor
timestamp: November 23, 2019, 09:07:29 pm
content: Hi all,This is Kevin A. I'm the guy who made the nixie power supply.I did drop ship Dave the same resistor I used for load testing from Digikey. Hopefully he does a follow up with some load testing.I did also take some FLIR images and videos of the supply running at a 200 milliamp load on the high voltage. You can check it out at the bottom of the post I did on this topic at:https://neonkev.com/2019/10/15/success-201-boost-at-40-watts-without-a-transformer/

author: Andrew McNamara
author_rank: Regular Contributor
timestamp: November 26, 2019, 11:49:54 pm
content: Quote from: 3roomlab on November 24, 2019, 01:28:46 amSome decent coverage here:https://www.bbc.com/news/uk-england-hampshire-49071456Some key points from the article:fire started in a robot's battery chargernot detected by fire detection systemengineer noticed the fire half an hour latersprinkler system activated, but was disabled for five minutes while they attempted to fight the fire by handthis allowed the fire to spread to the point where most of the facility was impacted400 staff laid off

author: Andrew McNamara
author_rank: Regular Contributor
timestamp: November 27, 2019, 12:02:05 am
content: Quote from: 3roomlab on November 24, 2019, 01:28:46 amHampshire Fire and Rescue's "Ocado Fire Contributory Factors" brief:https://www.esfrs.org/_resources/assets/attachment/full/0/28939.pdf

author: mcovington
author_rank: Regular Contributor
timestamp: December 02, 2019, 05:27:01 am
content: Why not load the 180V power supply with a 240-volt incandescent light bulb? Better than not being able to do the test at all.

author: CChin254
author_rank: Regular Contributor
timestamp: February 12, 2021, 05:55:17 am
content: Similar HTC Vive Base Station IC Identification: