Test Equipment Anonymous (TEA) group therapy thread

[AVGresponding]

What speed are you driving at?  My route finder says its about 465 miles trip from Anglesey and I have it set to the max speed for each type of road, and it thinks for your journey round trip, with no breaks for refuelling of any kind would be 9hrs 51 minutes                                                                                                                                                                                                                                                                                                                

I reran ABRB and now it says 11h 14m  including 2h24m for 6 charges.

Well you could use this, and sleep over here.

Would be a "holiday", the wife will love it.

[Andrew_Debbie]

Speed eats range because of i**r losses in the battery.

Speed eats range because the air resistance is proportional to the square of the airspeed. That's true for any vehicle.

Of course.  There are  tire losses, windage losses and others.   The i3 has tall thin tyres for a reason and it isn't good looks.



 In a BEV you are additionally hit with i squared R losses, mostly in the traction battery.   Drag goes up, current needed goes up  and the power lost in the battery goes up by the square of the current.

 In some EVs the  electric machine efficiency drops off a cliff at high RPM. LEAF was especially bad in this regard.  I could see the fuel gauge drop if I went up a grade at speed.   

The i3 has a more complex motor design and does not have that problem.   It is lighter too, which helps when climbing hills.


 

[Andrew_Debbie]

Would be a "holiday", the wife will love it.[/color][/size][/b]

In practice that is exactly what we do.   Much nicer than having to drive for 6 hours.      I'm not sure about dragging Debbie across the country for a used 'scope   

I recently qualified for a senior rail card  and 1/3 off most tickets.  -- If it weren't for covid . . .

[Specmaster]

It would need to be around its current price to make the journey to collect worthwhile and viable, its approx 360 miles round trip, about 7 to 8 hours driving assuming normal traffic conditions and around £60 for fuel. The probes don't worry me anyway, I have some insulated probes already. I expect the 2 bidders on it already are going closer than I am so would be likely to push that price upwards a bit more yet. I have it on watch and see what happens with it.

If I want to dissuade myself, my rule of thumb is 25p/mile for fuel and depreciation.

I work around 17p a mile, can't really factor in depreciation as that happens really just sitting outside the front door all year.

It has to be factored in somehow, so what do you suggest?

I've only bought 2 year old cars, so the initial heavy depreciation has occurred - and the remaining depreciation is largely mileage related. For want of a better figure, I'll assume a car will last 120kmiles and start with ^{(120000 - initialMileage)}/_{(secondHandPrice)}.

Insurance is the one that really isn't mileage related.

Depreciation is not just based on mileage, it's also based on age, my own car, for example, is 8 years in November this year and I have been the sole driver since it was new. I retired 5 years ago, and I negotiated with the leasing company when I retired, just before the car reached 3 years old, at which point, had I not retired, I would have arranged for a new car again. So my car is currently sitting on 68,000 miles, and doing approx 7 to 8,000 a year, and it is highly likely to out last me. So I don't know how you factor it in, especially in my case because my mileage is so low and variable, car is ultra reliable so I see no need to consider replacing it., It has no dents, rust or mechanical problems.??

[AVGresponding]

Well, early home today, "job and knock", mains change at one of our buildings, which is being repurposed for emergency planning/response.

We fitted the armoureds for the 50kVA UPS and 60kVA (iirc) genset a few months back, and they got installed and commissioned at more or less the same time. Today we swapped over the old supply which was fed from a building no longer under council control, to a new supply that NPG put in for us.
Our line manager had arranged for the building to be empty (it wasn't), and gave an elaborate description of how we'd have to power everything down. Bearing in mind, there's comms hubs for the cops there now, as well as parts of the council network, and that he hadn't pre-arranged for these to be turned off, I told the lead sparky not to listen to the fuckwit.
The whole damn point of the UPS and genset is the building ALWAYS has power (it's an online UPS and powers the entire building), so I told him we'll just kill the old mains, let the everything run on the genset until we're at the point of terminating the new armoured into the changeover, then kill the genset and let the UPS run the building on battery while we make our connections.
Given it has a nominal 30 minute runtime and was only loaded about 5% per phase, we could probably have done the entire job on battery...

Fun moments included no-one knowing where the keys for the genset cage padlocks were, discovering there were no padlocks on the genset cage just an m8 nut and bolt, the rotary isolator pulling off the wall when we tried to gland the new armoured in, and the inevitable jump scare when the changeover ka-chunka-chunks back over at the end of the job when all the power is back on.

[tggzzz]

It would need to be around its current price to make the journey to collect worthwhile and viable, its approx 360 miles round trip, about 7 to 8 hours driving assuming normal traffic conditions and around £60 for fuel. The probes don't worry me anyway, I have some insulated probes already. I expect the 2 bidders on it already are going closer than I am so would be likely to push that price upwards a bit more yet. I have it on watch and see what happens with it.

If I want to dissuade myself, my rule of thumb is 25p/mile for fuel and depreciation.

I work around 17p a mile, can't really factor in depreciation as that happens really just sitting outside the front door all year.

It has to be factored in somehow, so what do you suggest?

I've only bought 2 year old cars, so the initial heavy depreciation has occurred - and the remaining depreciation is largely mileage related. For want of a better figure, I'll assume a car will last 120kmiles and start with ^{(120000 - initialMileage)}/_{(secondHandPrice)}.

Insurance is the one that really isn't mileage related.

Depreciation is not just based on mileage, it's also based on age, my own car, for example, is 8 years in November this year and I have been the sole driver since it was new. I retired 5 years ago, and I negotiated with the leasing company when I retired, just before the car reached 3 years old, at which point, had I not retired, I would have arranged for a new car again. So my car is currently sitting on 68,000 miles, and doing approx 7 to 8,000 a year, and it is highly likely to out last me. So I don't know how you factor it in, especially in my case because my mileage is so low and variable, car is ultra reliable so I see no need to consider replacing it., It has no dents, rust or mechanical problems.??

It is indeed a complex topic, one that keeps accountants in "gainful employment"

Every mile you travel brings the necessity for shelling out the next car one step closer.

Nonetheless, I think my simplistic method is a useful starting point for deciding the cost of optional journey N+1.

[ch_scr]

Well, early home today, "job and knock", mains change at one of our buildings, which is being repurposed for emergency planning/response.

We fitted the armoureds for the 50kVA UPS and 60kVA (iirc) genset a few months back, and they got installed and commissioned at more or less the same time. Today we swapped over the old supply which was fed from a building no longer under council control, to a new supply that NPG put in for us.
Our line manager had arranged for the building to be empty (it wasn't), and gave an elaborate description of how we'd have to power everything down. Bearing in mind, there's comms hubs for the cops there now, as well as parts of the council network, and that he hadn't pre-arranged for these to be turned off, I told the lead sparky not to listen to the fuckwit.
The whole damn point of the UPS and genset is the building ALWAYS has power (it's an online UPS and powers the entire building), so I told him we'll just kill the old mains, let the everything run on the genset until we're at the point of terminating the new armoured into the changeover, then kill the genset and let the UPS run the building on battery while we make our connections.
Given it has a nominal 30 minute runtime and was only loaded about 5% per phase, we could probably have done the entire job on battery...

Fun moments included no-one knowing where the keys for the genset cage padlocks were, discovering there were no padlocks on the genset cage just an m8 nut and bolt, the rotary isolator pulling off the wall when we tried to gland the new armoured in, and the inevitable jump scare when the changeover ka-chunka-chunks back over at the end of the job when all the power is back on.

All-in-all sounds like a fun day at work 

[tggzzz]

Speed eats range because of i**r losses in the battery.

Speed eats range because the air resistance is proportional to the square of the airspeed. That's true for any vehicle.

Of course.  There are  tire losses, windage losses and others.   The i3 has tall thin tyres for a reason and it isn't good looks.



 In a BEV you are additionally hit with i squared R losses, mostly in the traction battery.   Drag goes up, current needed goes up  and the power lost in the battery goes up by the square of the current.

 In some EVs the  electric machine efficiency drops off a cliff at high RPM. LEAF was especially bad in this regard.  I could see the fuel gauge drop if I went up a grade at speed.   

The i3 has a more complex motor design and does not have that problem.   It is lighter too, which helps when climbing hills.

If you look at the reference I gave, it gives rules of thumb that for any type of car:

• at 16mph the drag dissipates the same energy as rolling resistance https://withouthotair.com/cA/page_259.shtml
• if start-stops are more than 750m apart, then the drag dominates the energy dissipation https://withouthotair.com/cA/page_256.shtml

So on the open road at 40mph or faster, drag is easily the dominant energy sink.

Where does the I²R dissipated in the battery fit in with those observations?

[AVGresponding]

A few eBay spots for your delectation:



This is some hitherto unknown to me definition of the phrase "good cosmetic condition". Personally, I'd describe it as "rough as a badger's arse":

https://www.ebay.co.uk/itm/203514379928


I am slightly tempted to bid on it to use as a parts mule for mine. Only very slightly though.



BD139 you need to buy this and make it run Doom:

https://www.ebay.co.uk/itm/133807354399




One for the Yankee RF boys:

https://www.ebay.co.uk/itm/144104358484




This thing has been relisted 6 times to my knowledge; last time the bidding reached just over £300, but reserve still wasn't reached. What a dumbass.

https://www.ebay.co.uk/itm/304056297454




Someone buy this for Mr Carlson please:

https://www.ebay.co.uk/itm/294260185864




The bidding on this will get intense I think:

https://www.ebay.co.uk/itm/373640974033




This is nice, and it's one of our own selling it:

https://www.ebay.co.uk/itm/144104726327




Not sure if this is a good price or no:

https://www.ebay.co.uk/itm/113005112150




That 3478A I linked the other day went for a maiden bid, so someone got a decent deal there. If I hadn't just jammie-gitted one, I'd have bid on it myself.

[Specmaster]

Would be a "holiday", the wife will love it.[/color][/size][/b]

In practice that is exactly what we do.   Much nicer than having to drive for 6 hours.      I'm not sure about dragging Debbie across the country for a used 'scope   

I recently qualified for a senior rail card  and 1/3 off most tickets.  -- If it weren't for covid . . .

I never even considered a senior rail card, but I do have a free bus pass and only used it about 4 times since I had it. Public transport is just to much of a drag to use, just getting to the dealers why where my car gets serviced, involves catching 2 buses and over an hour of time, it takes me literally 8 mins driving time 

I don't know about your journey for that scope by train, but for me that 4 trains, quickest is 4Hrs 15mins and longest is 12hrs 45mins and would cost £95 return booked in advance and the nearest stop is Skegness and a taxi ride for the remaining approx 15 miles, that is not an option.

[Andrew_Debbie]

Where does the I²R dissipated in the battery fit in with those observations?

--
Note: I'm going to use 'motor' here .  Electric machine would be more correct. 
--

Petrol engine effiency increases with load.       

At low power there are considerable pumping  and turblence losses as the engine creates a vacuum against the mostly closed throttle.    At idle losses are high.  The engine is doing little more than running the alternator but dumping  a lot of heat and some noise.

Effiency improves when the engtine is providing traction power and  is typically best near full power.

Diesels don't have  pumping losses and genereally hit peak efficenty around 50% power and stay close to that all the way to 100%.     Depends a lot on the engine design of  course.   

Some modern petrol engines adust  valve lift to reduce pumping losses.   I suppose that makes the curves look more like a diesel.


So while you do have v² losses, the thermal effiency gets better.  Fuel economy does not suffer as much as it would if the car had the same loss at idle as it does at 70% power.


BEVs are the other way around.    Effiency at idle is very good.  There is a DC-DC converter that provides power to the accessories. The heatpump (Aircon)  compressor uses a 3-phase motor.    At idle, the traction motor draws no power.     

Like a combustion engine car,  power required goes up approximatly by  v² because of the various drag components.     Watts  = E*I.   So current goes up linear with power.  This ignors motor losses, which go up with RPM in some designs, espcially PM motors like the one Nissan use.

 
Power lost due to resistance in the traction battery, inverter and elecric machine  goes up by  W = i²R.     R is small, but i isn't.     The losses are big enough that the motor and inverter need liquid cooling.    In cars with only passivly cooled batteries, (Nissan again) the pack gets hot and can even go into thermal limiting.

[Andrew_Debbie]

200MHz Siglent SDS1202X-E  is £360 from a UK siglent store.       That makes the  70MHz and 40k memory  SDS1072CNL  from China less attractive.   

[25 CPS]

Add to that. DRL's are a requirement in Canada which puts an additional load on your precious battery resource. Although LED headlights are a big help.

Are they a requirement in the US now too?  American regulations are not something I'm all that up to date on but I could've sworn I heard it was being debated there after we put that requirement in place.

Five or six years ago before my 1997 Dodge minivan was stolen, the flasher module acted up.  The left turn signal worked fine but indicate for right and it would flash a couple of times and then lock up and it was the same with the four ways.  I went to the local Chrysler dealership to get a replacement and it was a specific Canadian part because the same module also contained the relays for the daytime running lights.

[AVGresponding]

Forgot to add this earlier:

[mnementh]

Add to that. DRL's are a requirement in Canada which puts an additional load on your precious battery resource. Although LED headlights are a big help.

Are they a requirement in the US now too?  American regulations are not something I'm all that up to date on but I could've sworn I heard it was being debated there after we put that requirement in place.

Five or six years ago before my 1997 Dodge minivan was stolen, the flasher module acted up.  The left turn signal worked fine but indicate for right and it would flash a couple of times and then lock up and it was the same with the four ways.  I went to the local Chrysler dealership to get a replacement and it was a specific Canadian part because the same module also contained the relays for the daytime running lights.

I worked at a Dodge dealership in central NY around the mid 90s; even then the turn-signal-based DRL were present on all current-model vehicles and could be turned on or off with the DRBII.

mnem
 

[25 CPS]

Now we don’t want to do too much of that spend good money on good equipment thing because, well, if you aren’t at risk of your handheld test equipment exploding in your hand, you aren’t really living.

So, to that end:



Look at the low cost stuff the mailman brought me all the way from China:



That includes the correct BNC to banana socket adapters I meant to order last time.  The wrong ones actually did come in handy the other day though when I was testing the Fluke Scopemeter though.  I fed a bunch of function generators into load resistors to have something to clip the Fluke’s probes onto:



The idea there was to be able to test the set of probes it came with as well rather than going BNC directly into the Scopemeter’s inputs.  You never know when you’re going to need what adapter.  Next time I buy a handheld scope I promise it’ll be some cheap garbage that doesn’t work, doesn’t meet its specifications and has a non-trivial risk of exploding in my face because that’s how we like it!

Anyways, I’m off to go see if I can catch COVID-19 while I play chicken on the train tracks during a thunderstorm.

[mnementh]

Had a bit of a milestone with my son last night; he got his first soldering iron burn building a new lightsaber core so his friends could play without having to switch out on the one extra "combat-ready" (made for cosplay fighting; not Walmart toy-grade) lightsaber we had.

I am either doing something very, very wrong or something very, very right with his upbringing... 

mnem
"Son, that's just the iron's way of saying 'DON'T TOUCH ME THERE!' "

[med6753]

Add to that. DRL's are a requirement in Canada which puts an additional load on your precious battery resource. Although LED headlights are a big help.

Are they a requirement in the US now too?  American regulations are not something I'm all that up to date on but I could've sworn I heard it was being debated there after we put that requirement in place.

Five or six years ago before my 1997 Dodge minivan was stolen, the flasher module acted up.  The left turn signal worked fine but indicate for right and it would flash a couple of times and then lock up and it was the same with the four ways.  I went to the local Chrysler dealership to get a replacement and it was a specific Canadian part because the same module also contained the relays for the daytime running lights.

No, DRL's are not required in New York. Not sure if any state requires them. The Honda CR-V came with DRL's as standard equipment. Luckily it is a separate fused circuit. Pulled the fuse and no more DRL's. Now why would I do that? Simple. I had another vehicle with DRL's and I was changing burnt out bulbs seemed like every 6 months. Fuck that noise. 

[mansaxel]

the inevitable jump scare when the changeover ka-chunka-chunks back over at the end of the job when all the power is back on.

Remote-operated changeovers are an essential part of all show-off genset runs. You make a point to have people looking at something completely different but adjacent just about when you expect the "blink-free transition to grid" is going to take place. And then: BANG -- our switches were large ABB contactors with a quite aggressive sound.

[bd139]

A few eBay spots for your delectation:

BD139 you need to buy this and make it run Doom:

https://www.ebay.co.uk/itm/133807354399

Alas that's waaaay too slow for that shit. 1 frame per 30 seconds 

Someone buy this for Mr Carlson please:

https://www.ebay.co.uk/itm/294260185864

Stop listing the stuff on my watch list 

I am slightly considering ripping Mr Carlson a new asshole over that leakage detector bollocks at the moment. I have been scribbling notes through meetings on measuring capacitor leakage and breakdown at different voltages and his kit to work it out. I know what the conclusion will be 

Been taking a break to do something completely different today. Bought a Garmin eTrex 10, an absolute ass end GPS unit. This is because it turns out Openstreetmap actually has some mistakes on it locally. So being a good open source contributor I'm correcting them. Turns out this is quite good fun.

[bd139]

Also a funny looking tektronix 2235...

https://www.ebay.co.uk/itm/154522095141

[med6753]

Add to that. DRL's are a requirement in Canada which puts an additional load on your precious battery resource. Although LED headlights are a big help.

Are they a requirement in the US now too?  American regulations are not something I'm all that up to date on but I could've sworn I heard it was being debated there after we put that requirement in place.

Five or six years ago before my 1997 Dodge minivan was stolen, the flasher module acted up.  The left turn signal worked fine but indicate for right and it would flash a couple of times and then lock up and it was the same with the four ways.  I went to the local Chrysler dealership to get a replacement and it was a specific Canadian part because the same module also contained the relays for the daytime running lights.

I worked at a Dodge dealership in central NY around the mid 90s; even then the turn-signal-based DRL were present on all current-model vehicles and could be turned on or off with the DRBII.

mnem
 

The electrical manual for my 2004 Civic has 2 circuit diagrams for the headlights. USA model without DRL's and Canadian model with DRL's. The 2013 Honda CR-V came with DRL's as standard equipment.

[med6753]

Also a funny looking tektronix 2235...

https://www.ebay.co.uk/itm/154522095141

I don't think Tek bought Gould. 

[med6753]

the inevitable jump scare when the changeover ka-chunka-chunks back over at the end of the job when all the power is back on.

Remote-operated changeovers are an essential part of all show-off genset runs. You make a point to have people looking at something completely different but adjacent just about when you expect the "blink-free transition to grid" is going to take place. And then: BANG -- our switches were large ABB contactors with a quite aggressive sound.

You should hear when a large IBM Manufacturing complex loses power and the emergency lighting comes on. Place goes dark and complete freaking silence. But at the same time you feel and hear a vibration as the enormous hot start CAT diesels fire up. And then utter silence again. 

[Andrew_Debbie]

Add to that. DRL's are a requirement in Canada which puts an additional load on your precious battery resource. Although LED headlights are a big help.

Negligable.   DRLs are watts.   Traction is 10's of  kW.