Julian's Electronics Postbag:

[@jordanwaeles]

06:39 here is my bet for the wiggly tracks purpose: to separate as much the transistor/fet from the heat of the balancing resistor... making the track as long as possible so it doesn't conduct as much heat as a straight short track/has a chance to dissipate the heat.

[@giornogiovanna729]

Or a really low value inductor, tho seems a bit too small so your theory is more sensible.

[@yeso8205]

Trick only, no actual usage. small board is a over-voltage balancing one. When one cell voltage is over 4.25v, it starts to discharge. Meanwhile, the board with inductor on is an active balancing board, IC is ETA3000, this IC try to keep the voltage difference between 2 cells below 30mV. Balancing current is upto 2A. But, But, But, Good CELL/PACK ALMOST DOES NOT NEED BALANCING.

[@giornogiovanna729]

@@yeso8205"Good stuff doesn't need fixes" Thanks, my cell-balancing-disease disappeared almost immediately after that! Really useful!!

[@oreubens]

the wiggly lines are obviously to slow down the electrons. If they don''t slow down they'll fly off the pcb track and crash.

[@alankingvideo]

I wonder how many people were muttering “Thermal Isolation” under their breath for about a minute or 2, while watching that.

[@rich1051414]

I assume the wiggily tracks are to keep the resistors heat off the transistor. Transistors can cause thermal runaway conditions if you don't consider such things.

[@adamsmith2719]

It seems a typo - 100mA instead of 100A. The meandering trace is most likely a fuse.

[@jlucasound]

Cut out the rectangle in the battery box lid, along that recess and put in a piece of thin plexiglass. Now you can see the cells and you don't have that unsightly uncovered button and it's wires and hot glue blob.

[@alankingvideo]

If I remember making up ribbon cables correctly, the connector design is very annoying as the clip is designed with the cable looping back through, so you don’t get a straight run from connector to connector..if you don’t do it that way ten the clips don’t work. Alternatively you can cut some very small sections of ribbon cable to keep the clips in place.

[@dragon940carp6]

For the connectors. I would make a wooden spacer the exact distance the connectors will be when placed on the boards. Put that spacer between two connectors, slide the ribbon cable in, then squeeze the connectors in the vice.

[@JulianIlett]

A spacer jig - excellent idea :)

[@lasermike2147]

Way back in the day, 1984ish, we used an arbor press to install IDC connectors. A vise works just as well. To get the precision spacing you need, design a board with 2 headers at the correct spacing then solder the headers in. Put a connector on each, lay the ribbon cable on top the fit it in a vise or use an arbor press or even a drill press (pillar drill). The connectors don’t take much force but do need to be pressed squarely or they will break. Our cable assemblies didn’t use the extra part yours have. It provides strain relief to keep the wires seated in the forks, I think you can skip using that part.

[@jyvben1520]

Add some feet to the old battery box to protect the switch. Did you know : High Wycombe, Elevation: 75m / 246feet

[@gordanmilne7034]

Jyv Ben, High Wycombe undulates like distorted wriggly tin it is not a 75M flat plateau.

[@jyvben1520]

@@gordanmilne7034 Julian was talking about a waterproof box and mentioned there was little need for this because of the elevation. Hope Julian's house is not in an valley, when it rains like we saw in Spain.

[@shrikedecil]

Mount the boards (or hold them with vices/clamps) with precisely the spacing you want. Put the board-half of the connectors halfway or so into their actual sockets (making sure you have some way to get them back out!) Stretch the ribbon perfectly straight and where it needs to go. Press the back pieces partway in. Everything marked and semi-attached. Carefully extract from boards. *Now* use the vice to crimp them/press them in completely.

[@oreubens]

A vice is a good and fairly safe way to put on a connector on... It's somewhat slow, but if you only need to do a few that's ok. It's much better than trying to pit it on using a pair of pliers. There are dedicated crimping hand tools and even larger presses (in case you have to do hundreds a day). As to bridging the gap... Trying to make a straight through connection will require extreme precision and will make it hard to connect and deconnect the cable because there is no "slop" in the cable. Considering you like to "play" with the layout and design a lot, I woudldn't recommend a straight through on such a short distance. For bridging the small gap between the boards. The recommended way would be to put the cable through the connector, wrap the cable back into the strain relieve, then form an O-loop that sits "on top" and do the same on the other side of the gap. Tip: Make the loop big enough so you can fit your thumb through. If the above description is confusing... Check this image: i.ibb.co/02ZyQdV/ribbongap.png

[@professormarky]

You could cut the panel out of the lid and glue in a window if you wanted to keep them waterproof :-)

[@mariushmedias]

10:00 Why not experiment with flat ribbon cable and connectors? You can get flat flex ribbon cables with 1mm, 1.27mm, 2mm and 2.54 mm (0.1") pitch of various lengths, and you can also get connectors with locking mechanisms for your boards. For 1mm pitch 16 wide ribbon cables, they're as low as 30-50 cents each (varies with length) and connectors can be as low as 15-50 cents each in volume (100pcs) depending on how fancy you want (zero insertion force, low insertion force, locking mechanisms etc)

[@rizkyp]

It is amazing how fast the bin filled up with packing wrap when ordering stuff from eBay.

[@Dave2108]

IDC connectors are crimped with a hand held crimping tool Many on ebay.

[@MartenElectric]

www.ebay.co.uk/itm/IDC-Connector-Crimping-Tool-HT-214/122813658623 This seems to be popular on eBay

[@SimpleElectronics]

oh man, nothing better than Postbag!!

[@ProfessorFartsalot]

Put a LED in parallel with the output on the actual output wires so you dont have to break the waterproof :)

[@joea3728]

Try screwing the battery box lid on the bottom of the battery box, Instead of the top. You will not need to find spacers for the screws, and you will not lose the top.

[@oreubens]

You could also have salvaged a lot of ribbon cable from old PC's. the floppy drives and hard drives and CD players all have lots of ribbon cable. and you can easily split a 25pin into a single 12 pin (or into 2x 12 pin cables if you don't care about the one marked (pin 0) wire). An hour or so in the recycling center and you'll have cables for the rest of your life :-D

[@HMPirates]

Do these active cell balancers work if one cell goes overvoltage whereas the others are fully charged?(eg: 4.2;4.3;4.2)

[@Hasitier]

Normally I would say a PCB inductor but in this case it’s maybe to avoid getting too much heat from the resistors into the mosfets?

[@pulesjet]

That's my take too. Not enough room to just use more Track.

[@devttyUSB0]

Could the squiggly track be for heat sinking some off of that resistor?

[@haxxy40]

17:15 Nothing stops you to set the pack with the switch on the top after you've installed the cover. Unless you really like the color of those batteries and want them on display :)

[@DustinWatts]

@Julian Ilett In my days as an IT guy, we used a tool designed for clamping on the connectors. I never bothered to get one at home, I use one or two pipe wrenches!

[@williamsquires3070]

DARN - I was hoping for a second there that Julian was going to combine his Vocoder project with his DIY-breadboarded computer project using the ribbon cable to attach the vocoder to the 16-bit address bus. This would have turned the vocoder into a neat sound card for the computer! 😎

[@JxH]

Build your 0.1-inch cable in-situ. At least press them a bit in-situ, to mark the cable length precisely. Number them in case the spacing varies slightly.

[@paranoiia8]

In one way I like when boards are coated but damn sometimes I hate that when I need to scrap that just to check if tracks are good...

[@mkartky]

Those ribbons instead of connecting across the short gap you could loop out left and come in right leaving a small circular loop above the boards?

[@JulianIlett]

That could work :)

[@PracticalCat]

I also use a vice. But I sit a couple pieces of aluminum right angle on the jaws to protect what im pressing. The knurled steel can be pretty unforgiving.

[@JulianIlett]

My mini-vice has smooth internal surfaces :)

[@californiakayaker]

Put four aa lithiums in that holder and you'll have around 16 volts or there abouts. I prefer the 18650 version for that but not sure it comes with a switch and nice box, but they do have a series version, 2 , 3, or 4 cells.

[@bipolarchemist]

I have a dual voltage (±5) power supply with similar tracks to those going from the full bridge rectifier to the input caps of the 7x05 voltage regulators. Not sure of their purpose there either.

[@daque1960]

I've gotten a lot more microccontroller boards lately but really not done anything. Teensy 4.0 and a half dozen ESP32 ones. I'm looking for one with PSRAM so I can try micropython now.

[@helmuthschultes9243]

Vice is best way, consistent even spread of force and no slant insert

[@simmo1024]

I got a lovely letter from the Royal Mail too today. Apparently, I owe import duty of £3.51 on my Chinese bits. With a lovely £8 surcharge for the Royal Mail. That'll teach me not to buy a load of components from the same supplier at the same time. (Actually, I think it might be Alice). Grrr.

[@oreubens]

You have to make sure the seller doesn't combine smaller orders into a single big shipment. You'll have to check the minimum value when customs duty and taxes get involved. For Belgium the limit is at 20 Euro, including shipping costs. if you keep all shipments below 20Euro you're golden. it's funny really. Sometimes I buy a load of RC items one per day for weeks.... I don't get how they can do the free shipping, but it means I get everything substantially cheaper than ordering it all in one big purchase. (but you have to put in the bit of extra work and have patience.

[@simmo1024]

@@oreubens yeah I know. I'd forgotten. Think last time I got hit was buying DVDs from Canada back when that was a thing. The Post Office surcharge has annoyed me the most.

[@whitehoose]

Not seen a ribbon cable for years - some were in my house, garage or shed I have a 80 / 10 way crimper. It came with a set of dies to accommodate the various ribbons common in computers It was inherited from another team that folded just as I got my new position at work in the days when money was no object and I think when I got it it was still worth more than the house. The handles were about 3 foot long and because of the 6' reach it was a 2 hander, also had an extractor for pulling the plugs. But yes a vice was a good second option - while I could order a full range of crimpers and fancy gear costing £1000s - a vice wasn't seen as a legitimate purchase and I'd have needed to sell a kidney to get a purchase order signed by god to get one (I finally got a new 10" engineer's one as a swap for services rendered from our motor transport dept). They had 10 wrapped in oilpaper sitting unused on a shelf in their stores. Happy days!

[@TheRealSasquatch]

use a right angled male and female connector for the interboard connector

[@dutchmetalmaniac]

nice battery box to tweak. cut out the middle section of the lid and put a transparant window in. some led's in the corners under the lid to lighten the window. NICE....🌟🌟🌟

[@JulianIlett]

Like it :)

[@josephnealescratchcards]

Finally post bag video as always 👍🏻❤️

[@m3chanist]

Is that an English rainbow then ? ;)

[@MitzaMaxwell]

Why can't the last connector also be on the same page as the other PCBs? Especially now when it needs to change anyway. Is the PCB in the lower layer?

[@lumsdot]

How many transistors do you think you have in your house?

[@twotone3070]

Who doesn't have a vice for outdoor action?

[@weirdboyjim]

Nice mailbag as always thanks Julian. I think there is an argument for including more squiggly lines on pcb's purely for aesthetics.

[@JulianIlett]

Yeah - if I had the time, I'd like to use more curved tracks on my PCBs :)

[@melkiorwiseman5234]

I'm still waiting on my 3-cell active cell balancers. They were supposed to be here a couple of days ago at the latest. I hope they show up soon. And with that balancing board, I bet they just left out the m of mA when typing in the description. After all, they were careless enough describing it as a "protection" board instead of a "balancing" board.

[@nargalda773]

dute, in the SECOND when you touch the capacitors contacts and say "ofcourse, there is nothing in there" i remembered my old middle school teacher, who taught us work with low voltage devices, as we was young students, we cant work with electricity in circuits, so he must come and touch live parts as proof, that its without power, one day he probably forgot secure the switch and touch live part, get hit pretty hard by 250v and walk away with "wtf i was sure i switch it off", EVERY time, when i hear "feel free to touch is, its turn off" i remember that day, even if its over 30 years ago

[@247hinkey]

Julian - do you ever get worried to opening packages from China that may contain insets. I do sometimes question it.

[@JerryEricsson]

Man those prices are coming up! Don't know if I would pay 8 bucks for one of those.

[@The.Doctor.Venkman]

Late watching this, Julian. Really enjoyed it - Thank you.

[@JulianIlett]

Thanks Andy :)

[@rimmersbryggeri]

wigly track is probably a resistor.

[@uni-byte]

Vise, yep - that's how it's done in the plush, well lit Uni-Byte lab.

[@sdgelectronics]

Wiggly line looks like a fuse.

[@MjwAllMusic]

If you're looking for a good BMS, might want to look at batrium!

[@sharedknowledge6640]

The squiggly pcb trace is because most of the Chinese people designing these things have little idea what they’re doing. They just randomly copy other designs until they get something that sort of works and put it on eBay, Ali express, etc. There are all sorts of examples of things that make no sense to a real engineer but end up in Chinese products out of pure ignorance.

[@connorhardy7694]

Does it work out cheaper if you pay in dollars compared to pounds including PayPal fees for items from China?

[@matsv201]

When i tested it does

[@Mark1024MAK]

Depends on exchange rates and on which seller you are buying from...

[@matsv201]

Can anyone explain why a 18650 cell cost €10 ... But a normal tool battery that have like 10 cells in then cost €40

[@JanJeronimus]

This is becouse mathematics rules we learned at school do not work in the big real universe. I also have seen examples on Aliexpress where 1 item costs 1 euro. And if you buy 10 of that items (at the same seller) you need to pay 11 euros. So always check prices and sometimes it is cheaper to buy more than you need and sometimes it is cheaper to split your sale and buy eg. 5 and a few weeks later again 5 if you need 10 pieces.

[@matsv201]

@@JanJeronimus yea.. the most anoying i seen was one item cost 1.54... two item cost 3.08... fine... Three items cost 6.85... what a f... 4 items cost 10.53.. This makes no sense what so ever. So i ordered two items .... Two times.

[@Mark1024MAK]

Jan Jeronimus - same thing sometimes happens in supermarkets!

[@Markus0021]

@@matsv201 Yeah, I've seen similar strange prices on Amazon. Like 2-pack for $2.50, 3-pack for $5.00 - why wouldn't I just get 2 of the 2-packs and end up with 4 items for $5.00? Why would _anyone_ buy a 3-pack? Crazy.

[@PetRatty]

@19:00 just waiting for Julian to put the batteries in the wrong way around, not this time, shame, wanted to see smoke

[@californiakayaker]

@julian Ilett Your probably sleeping by now ? It is actually quite amazing what I am seeing regarding super capacitors lately . SUPER FAST CHARGING and DISCHARGING. They think it will revolutionize the electric car market . They will have super fast capacitor to capacitor charging stations and discharge directly into the car motors ! I have a video about this if your interested .

[@KevinOsborne1987]

Afternoon..

[@Mark1024MAK]

Evening all 🙂

[@asagk]

Ich wish I had my envelopes from China today as well. You are a very lucky person to get them in time! :)

[@lingcod91]

Stop with the Links . . . they don't work. There, I saved you and anyone else, some time.

[@ShowtimeEnt404]

Mr Julian I have a project I would like to get your opinion on. May I leave you my email for details? Please and Thank You

[@SuperFlons]

Stop buying so much. You do not need it and are unnecessarily harming the environment. I know you mean no harm, but please consider buying a bit less.

[@publicmail2]

A millennial dictating his socialist ideas because he doesn't have 2 nickels to rub together.

[@joea3728]

Try screwing the battery box lid on the bottom of the battery box, Instead of the top. You will not need to find spacers for the screws, and you will not lose the top.

[@webchimp]

Or put them back in the bag with the lid which he said he also wants to keep.

[@eidodk]

@@webchimp But the Lid would be on the bottom, so it's kept, and it's level, and it's together with the rest of the box.

[@joea3728]

Try screwing the battery box lid on the bottom of the battery box, Instead of the top. You will not need to find spacers for the screws, and you will not lose the top.

[@PetRatty]

just about to say the same thing