The odd pearl for someone who needs a hyper specific video about an niche topic. The content here is mostly odd moment that I happen to find interesting in my electronics projects and my observations of the MBTA's infrastructure.
I think the thing you are talking about at the end is not really an issue. Yes, the user interface is a bit hectic, but it makes sense to me. We have "volts, amps; volts, amps" for the 7 segment display, which is natural. The voltage knob is always on the outside.
It doesn't match the alignment of the LED displays. It's the asymmetry that is begging for a user setup error. Once more other power supplies get this right.
Citations for each slide slide 1 None recorded interview conducted before we had guests over last December. slide 3 vimeo.com/40582561 slide 4 MBTA slide 6 I got this from Hamden CT Fire Department's Twitter post which they have since removed but you can find it on other validated news sources. This copy is zoomed in but it's the same picture. www.ctpublic.org/news/2022-07-27/fire-causes-cttransit-to-suspend-use-of-electric-bus-fleet slide 7 "Fire on Battery Electric Transit Bus" www.ntsb.gov/investigations/AccidentReports/Reports/HIR2403.pdf slide 8 "HWY22FH011 FACTUAL REPORT OF INVESTIGATION" data.ntsb.gov/Docket/Document/docBLOB?ID=15814806&FileExtension=pdf&FileName=002%20HWY22FH011%20-%20Factual%20Report%20of%20Investigation-Rel.pdf slide 9 - citation error this is page 16 of "HWY22FH011 FACTUAL REPORT OF INVESTIGATION" page 16 data.ntsb.gov/Docket/Document/docBLOB?ID=15814806&FileExtension=pdf&FileName=002%20HWY22FH011%20-%20Factual%20Report%20of%20Investigation-Rel.pdf slide 10 "Fire on Battery Electric Transit Bus" page 4 www.ntsb.gov/investigations/AccidentReports/Reports/HIR2403.pdf slide 11 "How 'modern-day slavery' in the Congo powers the rechargeable battery economy" www.npr.org/sections/goatsandsoda/2023/02/01/1152893248/red-cobalt-congo-drc-mining-siddharth-kara slide 12 Various battery datasheets from vendors and my own experiance designing devices with these products. slide 13 "The NexGen Electric Trolley Bus: How does it work?" www.daytondailynews.com/data/news/nexgen-electric-trolley/ note: The story as I viewed it originally was interactive with complex web scripts that let you click and zoom in on parts of the bus. They seem to have removed that when it became old news. I guess it was expensive to maintain/run? slide 14 cdn.mbta.com/sites/default/files/2019-12/2019-12-09-fmcb-J-bus-procurement-accessible.pdf slide 15 - Please see note in earlier comment about this slide cdn.mbta.com/sites/default/files/2020-09/2020-09-14-fmcb-L-bus-electrification- accessible.pdf slide 16 & side 17 "Duluth Transit Authority Battery-Electric Bus Evaluation" www.nrel.gov/docs/fy22osti/83038.pdf slide 18 - Please see note in earlier comment about this slide cdn.mbta.com/sites/default/files/2020-09/2020-09-14-fmcb-L-bus-electrification- accessible.pdf slide 19 kingcounty.gov/depts/transportation/metro/programs-projects/innovation-technology/zero-emission-fleet/electric-trolley-bus.aspx slide 21 This is a file someone inside gave me with there own writeup of the emissions. I will share a copy of it and the "Hatch" report later. slide 22 www.iso-ne.com/about/what-we-do/in-depth/solar-power-in-new-england-locations-and-impact slide 23 Again later I will post links to the "Hatch" report in a few versions and the analysis of it showing this. slide 24 cdn.mbta.com/sites/default/files/2020-09/2020-09-14-fmcb-L-bus-electrification-accessible.pdf slide 25 whyy.org/articles/septas-cracking-battery-buses-raise-questions-about-the-future-of-electric-transit/ www.inquirer.com/transportation/septa-proterra-electric-bus-battery-fire-philadelphia-20221111.html www.inquirer.com/transportation/septa-flawed-battery-electric-buses-proterra-bankruptcy-20230906.html wwww.septa.org/news/septa-board-approves-purchase-of-10-fuel-cell-buses/ Meeting minutes on the budget hearing for the data listed. slide 26 www.bostonglobe.com/2023/04/03/metro/more-bus-garage-delays-blown-budgets- put-t-fleet-electrification-goal-doubt/ The cut down to $400M is from the board meeting presentation in the following slide. 2023.07.27 slide 27 www.mbta.com/events/2023-07-27/board-meeting-mbta-board-directors livestream.com/mbta/events/10894143 cdn.mbta.com/sites/default/files/2023-07/7.%20MBTA%20Bus%20Facility%20Modernization%20Program_Boardupdate_07-27-2023_v16.pdf slide 28 www.welt.de/vermischtes/article234310454/Elektrobus-lOeste-Grossbrand-aus-Muenchen-zieht-E-Fahrzeuge-aus-dem-Verkehr.html?icid=search.product.onsitesearch www.dw.com/en/germany-large-fire-at-stuttgart-bus-depot/a-593725 insideevs.com/news/583324/paris-suspends-149-bollore-electric- buses-after-two-fires/ slide 29 www.sfmta.com/blog/new-muni-trolley-buses-coming-all-electrified-routes-2019 slide 30 SFMUNI slide 31 MBTA slide 32 openlibrary.org/books/OL23350735M/Trolley_buses_on_Washington_street.
<Correction on the slides 15 & 18> Currently only one issue has popped up. Two people doubt the replacement ratio. MBTA has admitted it's not 1:1 but they haven't said what it is now. I assumed it's still the 1:3. The 1:6 figure I got from their testing was prediesel heater was included. That is why I included the Duluth study done by NREL (National Renewable Energy Lab) which resulted in the 1:4 figure I highted. I believed this figure because Duluth was comparing a battery powered bus with a battery of slightly larger energy storage capacity and a diesel heater of possibly cleaner operation than the buses MBTA ordered. I was going using the mileage from when they were running, they spent a lot of time broken down. Project planner's from that study blame early tech. Others blame a bad vendor (proterra) which is totally fair. They argued possibly correctly that the 1:4 ratio was just another form of poor proterra performance. If anyone else had suggested I dump this comment I would have but the two people are folks who by reputation I have to respect enough to subtract this one objection... That said, all the other facts related to limited performance stated are verified to be correct most critically: the T will still be changing from multiple drivers per bus to multiple buses per driver as best I can tell. The range is only 120miles on a charge and that full recharging takes 6 to 8hours depending on weather. Longer if they use more than 1/3 of their chargers In a depot. Along with of course still burning diesel fuel. </Correction on the slides>
<A Correction to the Correction> I was right all along. People tried to blame Proterra and Duluth's bad hills but here is another example from MN. Look at page 3. The price per bus is still double and the stops per day is still 1/4 of what the conventional buses will be doing. metrocouncil.org/Council-Meetings/Committees/Transportation-Committee/2023/June-12,-2023/0612_2023_121-SW-presentation.aspx
The trackpad kept crashing on me. It would lockup after a few hours of use. The weird part is it would stay nonfunctional after a reboot. I sent it back and they are working on it now.
@@KentonVizdos They serviced it and returned it to me. The touchpad is better but honestly the whole thing is still garbage. It's developed other problems including various issues with ACPI. These things are lemons. Seriously folks if you have the money buy something else. Did yours work out any better?
They said the 2nd fan was not intended to operate. I am also having issues with the trackpad. They have told me both issues will be addressed in a firmware update but that was nearly a week ago. I actually had to defend my wanting both fans to work.
@@TheEmT33 To be clear they were very responsive as a company and when my order originally went to manufacturing they gave me a personal phone call. So it's not like they are a bad company. I hope this was just a bump in the road.
They serviced it and returned it to me. The touchpad is better but honestly the whole thing is still garbage. It's developed other problems including various issues with ACPI. These things are lemons. Seriously folks if you have the money buy something else.
Reminds me of when I reported the condition of the South Attleboro commuter station in 2013. Nothing was ever done and eventually the station was condemned by the state
Hi, thanks for the video. I have one of these HP3325B I am a complete novice and didn't appreciate how good the analyser is and to be honest I cannot use this machine for its capabilities. Could you please do a video on the basics and explain its functions I would really appreciate the help. I am in UK. Kind Regards, John.
@@johnmcgiv1 And you started by buying an HP 3325B function generator? That's a bold move. I will see what I can do but the politics of my country require some of my attention right now too.
I did the same, just bought a HP3325B for the fun of playing with it. I'm planning to evaluate my HIFI crossovers and learn how to trouble shoot my amps. Any new videos would be fantastic.
It is also used for calibration for HP 3561A, which is a masterpiece by itself. In the service manual, it is listed as a reference unit for most of the adjustments.
I just measured five different scopes, all measured between 45 to 51 ohms from u800 studs to chassis. Not that it matters for measuring 50 ohms, but I used an Agilent 3458A 8.5 digit meter.
Be careful 2400 series includes the digital scopes 2430a, 2432, and 2440, etc. The mainboard is in no way similar in those. Where do you get that U800 has a penchant for overheating? This is internet BS probably started by someone who assumed that. In fact, with the cover on u800 runs at less than 120F. This is real data collected by me. U800s do fail but the failure is probably not heat related. The two studs on U800 are not ground, they are 50ohms to ground. The studs are in fact at -5V.
The Tek Scopes Yahoo group and at least 2 former tektronix employees told me. The chips were originally made by them but they sold the fab to Maxim who could not maintane the same yeld figure and eventually they had to give up on it. No one would confuse the later model digital 2430A, 2432, or 2440 with the analog 2445, 2465, or 2467. The mainboards are totally different.
The Maxim yield as nothing to do with how hot the chip runs. The maxim version of the U800 is just very low reliability and no amount of heat sinking is going to make the Maxim version good.
The -5V distribution goes to pin 19 and 25. Pin 25 is the metal tab since it's a 24 pin device. When the device is installed in a scope pin 19 and the tab are shorted together and obviously have -5v on them. I verified this on several 2565Bs. I don't why you don't measure -5v on the studs and tab. I have worked on hundreds of these and that is what I've seen.
It's also ironic, I posted a video today of a Hantek power supply that was DOA and self immolated when powered up with *no* load. It has a really nice toroidal transformer that the vendor wasn't even using all the secondary windings on! I would never use one of those but I am so tempted to buy one for cheap just to get the transformer.
Keep in mind this is hardly the greatest power supply. I mean I understand wanting a proper review of performance but honestly the knobs being reversed relative to the displays is a total deal breaker for me. We kept this unit, my boss is going to use it. I think he sees this bug as a theft deterrent feature. I liked the keysight multichannel power supply and I have an as yet unposted review of it. The thing is I don't want to have the lab buy 20 of them ($1,500 each) that adds up fast. This is why I am reviewing power supplies that are under $500. We did buy 12 tektronix single channel output supplies a while back for a project but those were like $400/unit... took a photo of myself sitting on them actually... www.flickr.com/photos/evanfoss/36930763493/
Where I work. Eaton Peabody Lab. This video was actually made for a few customers (former students of the lab) who paid me to build them copies of the stuff I had worked on for their thesis projects.
Looking later I found that at least one was not. I also checked if the bridge rectifier was rotated, it was not. I now believe that in all their wiring and crimping they probably plugged something in wrong. Perhaps they wired the wrong transformer winding. I returned it, and told them if they intended to every have me or my institution as a customer again they would have to explain both the failure that happened and provide me with some process change they had made to reduce the odds of recurrence. My lab is in a hospital, what if this had happened when I wasn't there to unplug it?
For this machine I looked up in the HP service manual (which in that era still included the schematic) what the part number was and I think I just bought the same cap. This was a mistake but one I will only have to deal with in another 15 or so years.
The better plan is to look up the original part in digikey or a vintage catalog, find out what the spec. was and just search for that. Give me a sec. to search my old digikey invoices....
Mfr. part for the tek scope was this PME271M568MR30 and it was digikey 399-7482-ND. So I would start with 0.068uF, 20% or better, 275V, and 0.532" lead spacing. Ideally the other key characteristics would be better or equal too the original (high and width, temp. range, X2)
@@ElectricEvan yea...i have the tek manual and to my recall...the description lacked what these are called...ie package type... i have not looked into any tek databases.
