Julian's Postbag:

[@deathshaker0026]

Oh Julian it made me laugh when you where scooping the beads out with a spoon like its cereal. :)

[@JasonMasters]

The trouble with those little DIP switches is that they're intended to be set and then left and only changed rarely if ever. They're probably made to a price rather than to a quality because whoever made them thought they'd be moved back and forth a few times at most and then never moved again.

[@stinkycheese804]

"Maybe", a quality major brand will typically rate their switches for number of cycles and it's more than just one to a few cycles, but yeah the generic stuff, if it works at all you should never touch it again, lol.

[@DrGreenGiant]

Yay tantrum caps. I feel like such a child when I intentionally over volt them and watch the fireworks 😂

[@majdinj]

Why you don't use ceramic smd capacitor?, They come with1uf and 10uf values on 0805 smd package. Why you choose tantalum?

[@cypherf0x]

The solvents in the solder paste for the flux are normally alcohol based along with other volatiles. You should always store them at a lower temperature above freezing to minimize loss of those through evaporation. Do not use any desiccant as that will only cause more to evaporate until an equilibrium is reached in the container. ziplock bags are good just remove any excess air without creating a vacuum condition. The less space for gasses, the less evaporation it will take to reach an equilibrium. The thick heavy duty freezer bags are the best. Anything being stored for an extended period has a corner left open and then the rest of the bag is submerged to remove the air before the corner that's still open is sealed. Then it goes into the fridge. I've seen some use pressurized containers, but it's just more work and solder paste isn't that expensive.

[@holymoly2353]

I'd be very interested to know what you're using for your PCB layout...

[@ElmerFuddGun]

Ya, the metric SMD sizes aren't always exact conversions from the imperial. I think a bit of rounding was done for some. The 1206 for example likely started as a metric size, 3.2mm, and was converted to imperial .12598" and rounded down instead of up. That's my guess at the moment... 5 AM here and I just happened to be getting up but it is still early to be thinking too hard! ;-) Search for "SMD imperial metric" and view images to see some tables.

[@johndii2194]

Lettered beads were strung on a string in the 50s and put on newborns wrists for ID.

[@zeberto1986]

10 types of beads, those that are numbered and those that are not...

[@JulianIlett]

What if you start counting from 0?

[@Aaargh306]

Ummm.... I think he means 10 binary = 2 decimal

[@robfenwitch7403]

The 'A' on SMD tantalums is the package style which include the height or depth

[@irgski]

Julian, measure those SMT caps...some “fraudsters” will sell you, effectively, an empty tantalum package, with nothing inside! What hexadecimal display driver are you looking at? Perhaps the common anode is the correct display if the driver provides a LOW output driver (negative true) for each segment.

[@yeet1337]

What's the practical difference between using electrolytics and tantalum caps, other than tantalum might work longer and are much more expensive?

[@TKomoski]

Have you thought of using rocker dip switches ?

[@JulianIlett]

+T Komoski No, I hadn't, but I like that idea :)

[@Brian_Of_Melbourne]

AliExpress have some 'toggle' style: www.aliexpress.com/store/product/10PCS-2P-3P-4P-5P-6P-8P-10P-bits-2-54mm-DIP-switch-digital-toggle-switch/3171020_32830638428.html?spm=2114.search0104.3.278.136d539cmryc64&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10151_10065_10344_10130_10068_10324_10547_10342_10325_10343_10340_10548_10341_10696_10192_10190_10084_10083_10618_10307_10820_10301_10821_10303_10059_100031_10103_10624_10623_10622_10621_10620,searchweb201603_54,ppcSwitch_7&algo_expid=cd7cc5dc-5140-40f5-b575-4e7da5e30dff-42&algo_pvid=cd7cc5dc-5140-40f5-b575-4e7da5e30dff&priceBeautifyAB=0

[@williamsquires3070]

TIL311 display already has the chip built-in... if you can find them. 4-bit input hex display; saves space as you don’t need a separate decoder IC. Has internal latch, so they can be multiplexed. Also has blanking input, and left/right-hand decimal points. Just google “TIL311” for the pinout! 😍

[@JulianIlett]

I have 2 of them on an old Z80 project :)

[@TheDirty360]

I put a bit of hot glue on the paste dispenser tip to seal it between use. Stops the paste from hardening in the tip. Otherwise you might as well throw out the whole thing if you leave it for more than a day. Don't get too worked up trying to put the paste on perfect.

[@JulianIlett]

Yeah, I'm going to treat the tips as disposable.

[@KX36]

does silica gel aDsorb water onto its surface or aBsorb water throughout it's centre?

[@simontay4851]

16:40 higher gauge number means smaller hole? That's weird!

[@dentakuweb]

It's the same with wire. Higher numbers mean thinner wire.

[@sidharthap]

Try buying components from LCSC.com for the femto

[@ThatGuy-nv2wo]

About the chip to decode a number to display onto the 7 segment display, why not just use an eeprom?

[@KadahCoba]

Be careful about SMD caps of eBay, their real ratings can be very different than to what's marked. JCLPCB does sell parts. If you're looking for cheap, I trust them over random eBay sellers, plus you can combine DHL shipping with PCBs.

[@yeet1337]

*LCSC sells parts

[@keithburton99]

What is the 7 segment hex driver chip for common cathode displays? I wanted one but have not found any

[@JulianIlett]

MC14495 HEX to 7-Segment Decoder

[@keithburton99]

These are obsolete and therefore difficult / expensive to obtain. A cheap micro controller and any display is probably a better bet see HSEG1000

[@bardenegri21]

I keep my solder paste in the fridge, seems fine after 2 years now.

[@Okurka.]

My fridge is still fine after 10 years.

[@KadahCoba]

The paste that requires frigeration tends to have at least a 12 month shelf life. Paste that had been stored badly (specify before you get it) tends to go hard. Decent solder paste should be dispensable by hand. Once you try a good quality solder paste, you can quickly tell the difference between good and bad paste. Good paste it's like magic if you've only used trash paste previously. :D

[@stinkycheese804]

Put it in your food dehydrator to draw the water out, and store it in an air-tight container. Many years without refrigeration, then when it comes time to use it, don't get it confused with your beef jerky which does not hold components on PCBs well at all.

[@stinkycheese804]

Keep perishable food in a fridge? That is a remarkable high tech solution that WTFBBQ didn't need stating.

[@RobertBaruch]

Interesting idea with the beads! I thought maybe you had a project to put ten of them on a disc and then make a fun clock or readout or something. Or get A-F and make a hex readout :D

[@km5405]

you can get those labels that come on a large string and are used in commercial installation a lot too.

[@Anvilshock]

Didn't you order some digital slide rules some postbags ago?

[@barrycrowder]

I enjoy your videos, Julian. I have been watching, so I know that you were using air to prevent the paste from continuing to flow after mechanical pressure is applied. But as you are experiencing, the advantage that it gives in that air is compressible and therefore gives a nonlinear response also brings a tradeoff. I think you are on the right track in attempting to limit the amount of air, but I think you need to think about the entire volume of air, not just the part near the dispenser. I look forward to continuing to watch and see how this turns out!

[@JulianIlett]

I'll be using the syringe digitally - just on or off (full pressure / no pressure). That results in a fixed flow rate of paste through the nozzle. Yeah, the beads reduce the air volume in the syringe - the pipe can be cut shorter if necessary.

[@maicod]

the neighbour's cut your ruler into pieces with his hedge trimmer Julian ? (otherwise you could've used it to measure those tiny caps LOL)

[@km5405]

aren't tantalums more prone to failure? (I.e. why tantalum, are you really that tight on space?)

[@jmanbrosef689]

PWM FEMTO!!! I have made 10 of the pwm gumstick. Now I need some of thoose femtos.

[@JulianIlett]

Oh, cool - details coming soon :)

[@slucas601]

My boss had a sign in his office that said "Good, Cheap, Fast ... Pick any 2"

[@simontay4851]

Good, fast. Cheap things are neither fast or good.

[@reeseyme9613]

nah, i just stuck blue tack at both sides of the logic switch to stop the wobbly and it goes with the color too

[@ronalddhs3726]

Hi Julian, good one; I just received a couple of packets from China myself (3 Dip type arduino unos and a I2S decoder/amplifier board). Order a couple of project parts here and there, makes it like Christmas everyday ;). Keep it going.

[@nutsnproud6932]

Julian, I keep my solder paste in the fridge. I hope that helps.

[@JulianIlett]

I don't have a fridge - I have 50% voting rights on the use of a fridge. Guaranteed stalemate :)

[@nutsnproud6932]

Same here. The dragon does let me keep one tube in that's been opened.

[@simontay4851]

Get yourself one of those tiny peltier element powered fridges to keep your paste in. The ones you can fit just 2 or 3 330ml cans in.

[@TKomoski]

Let me guess the wife has the other 50%

[@kaoshavoc]

That is about the most accurate description of a marriage I have ever heard LOL. Also, a mini fridge for your refreshments and solder paste could be in order LOL.

[@RupertHandford]

Julian What are you thinking of driving the 7 segment displays from?

[@JulianIlett]

MC14495 HEX to 7-Segment Decoder

[@RupertHandford]

Why not just use an EEPROM then you can use either type display?

[@stinkycheese804]

Your solder paste contraption looks overly complex, is solder paste really that expensive there, to the point where you just can't waste a tiny amount? I just fling the paste in the general direction of the PCB and any that's off the pad a little, either moves over to it when heated or just washes away when I clean the board.

[@maseratiolli]

You don't need a precise amount of solder paste on your board. Just spread a line of paste across all of the pads (the flux will do the rest). Also the solder paste should be stored at around 0-10°C and should never exceed ~25°C.

[@jort93z]

or you get an smt stencil(JLC pcb makes those) and put it on the pads that way. just put a nice blob of solder paste on the stencil and then spread it with a spatula over all the openinings. You can get a board done in 10 seconds that way and don't lose any paste(because you leave it on the stencil for the next board).

[@superdau]

Yes, SMD package sizes can be given in metric or imperial units. Most manufacturers use metric, because the very small sizes like 0201 (0.2x0.1mm) would look like 008004 in imperial (and many of the SMD specifications are metric to begin with). Almost none of the codes appear in both measurements though. You have an 0805 and 1008 in imperial for example, but a 1005 is the closest in metric (numbers, not size obviously). But as luck would have it, the only two that do have an equivalent are the typical hand solderable sizes (0603 and 0402 imperial). Watch out to not get the metric size for those!

[@simontay4851]

0201! That's absolutely tiny. 0.1mm I couldn't even see that let alone solder it. How does even a pick n place machine pick up parts so small as they use vacuum to pick up parts.

[@superdau]

I don't know. Sprinkle them over the board and hope something sticks? I'd really like to know that as well. Apparently it actually is a point of higher failure rate in production. So it's not what you would want to use if you didn't have to.

[@chrishartley1210]

I wondered if 1206 actually referred to the pad size

[@AndersJackson]

I guess there are equal ammount of 1 and 9 perls. That is aktually a bad distribution, as we use many more 1 then 9.

[@krishna34674]

2:00 haha now you have a numerical 0 mixed in with your letters.

[@Okurka.]

Nope, that's the letter O.

[@whatthefunction9140]

Where can I buy a pwm5 for a 18650 battery pack?

[@TKomoski]

Online or your local electronics store

[@C32-d5j]

8:18 where they any better ?

[@JulianIlett]

Not tried them yet :(

[@Durrdalus]

Why not just transfer the solder paste into a regular syringe?

[@JulianIlett]

Sounds messy :)

[@station240]

It doesn't need to be messy, put the regular syringe needle into the original, pull back on the plunger to suck the paste in. There is another way to get this sort of paste type material into a syringe, remove the plunger and put it in the fat end.

[@SidneyCritic]

Make a bigger hole or snap the front of the paste syringe and plunger it into another syringe. You are going to have to take the paste out and mix more flux into it to make it flow again, or it's going straight in the bin.

[@aurthorthing7403]

When are you going to finish that capacitor powered bluetooth speaker?

[@jcm4377]

Aurthor Thing get a chair..

[@simontay4851]

And popcorn. You'll be dead before he finishes it.

[@TKomoski]

And wait your turn

[@josephnealescratchcards]

Awesome video as always

[@trottx]

The technical term is "loosey goosey" for that switch that is no longer tight. Rigid and flaccid are wrong on many levels.

[@JulianIlett]

Ak, thanks :)

[@becky15675]

Those beads, that's NUMBERWANG!!

[@dazzjh40]

Been watching you for years Julian - Have you ever finished a project!

[@rimmersbryggeri]

Are you saying he is the George RR Martin of electronics youtubers?

[@JulianIlett]

Cheers :) No.

[@simontay4851]

Yes you have. You have old projects from the 80s/90s that you've showed in previous videos.

[@TKomoski]

LOL

[@dazzjh40]

Not sure even the ones from the 80s were actually ‘finished ‘

[@warrenmasters3036]

IIITTTSSS MAAAIILBAG! YAY!

[@rickgraham8701]

These are fun. Everyone likes opening packages.

[@MiggyManMike]

3216 (3.2x1.6mm) is metric, 1206 (0.125"x0.06") is imperial and in this case they are the same size:) There's a decent list on the wikipedia page for smd tech:) en.wikipedia.org/wiki/Surface-mount_technology

[@JulianIlett]

It's a strangely inaccurate conversion :)

[@MiggyManMike]

It's not perfect (it's not uncommon with metricimperial) , it does get better if you use 0.125 instead of 0.12 but the package name itself takes some accuracy away :D

[@tomgeorge3726]

Hi, this might help, imperial/metric SMD sizes. www.topline.tv/sizechart.html The solderpaste applicator project, unfortunately air is compressible. You need a fluid as you have no compression.

[@benbaselet2026]

Well air is a fluid. Clearly he needs an incompressible liquid, like water.

[@Strawberrymaker]

8:26 nice guitar riff lol

[@maicod]

David Watts had even worse, he had screaming kids from both neighbours coming through :)

[@lukaszavada]

*START RECORDIIIIIIING!* _Julian Ilett, 2018_ 😂😂😂😂😂😂😂😂😂😂😂😂😂

[@TKomoski]

Lukáš Závada *NOW* *STOP*

[@rodwatson3488]

See the Tantalum SMD dimension table at www.microfarads.com/times-articles/111-eia-metric-size. 3216 is in mm and corresponds to 1206 in tenths of an inch

[@Chriva]

From stiff to flaccid.. We all suffer from that with age, man :D

[@SpeccyMan]

Speak for yourself mate. :D

[@simontay4851]

I don't. I'm stiff pretty often.

[@maicod]

Simon Tay you need a massage then....... *ahum* what did I say :)

[@quacka7376]

Love getting to notifications for your videos

[@RupertHandford]

Remix the dry solder paste with flox

[@marcus0018]

if you are interested i have a solder dispenser machine and might have a reflow system up for grabs

[@SomeMorganSomewhere]

3216 (Metric) = 1206(Imperial) There's a handy conversion chart here en.wikipedia.org/wiki/Surface-mount_technology

[@watermelon9588]

*SKOOKUM AS FRIG +1*

[@stevejones8665]

What Hedge Trimmers all I can hear is a Neighbour's Alarm 5 house's down the steet going off like a Cat being strangled Low Battery I suspect it's now 05:30am and it's been going for 2hrs😠😠....Hence why I am up watching this video....your Audio is fine.

[@douro20]

If you weren't so far away I'd send you a few vintage LED displays.

[@dhanikaniranga5701]

I love postbag

[@JulianIlett]

Thanks :)

[@LemoUtan]

good and cheap (but not fast)

[@jtreg]

The meds are wearing off Julian

[@MikesDIYTeslaPowerwall]

Love Postbag

[@God-CDXX]

MC14495 HEX to 7-Segment Decoder

[@JulianIlett]

That's the one :)

[@God-CDXX]

I have ben using them to build clocks

[@Brian_Of_Melbourne]

80 pence each on AliExpress seems quite good. A much better price than TIL311 (sweet though they are).

[@God-CDXX]

I have 450 TIL311 I have not played with them in 10 years I got 500 them of EBay way back wen . I may have to dig them out

[@JulianIlett]

+Jamie Phillips I think I have 2 of them :)

[@iceberg789]

you can live with common anode i guess.

[@electronic7979]

Nice items

[@jensschroder8214]

7 seg. display see: www.electronicshub.org/wp-content/uploads/2014/03/Common-Cathode-7-%E2%80%93Segment-LED.png

[@dlinnoedlinnoe]

JFYI 0402=1005 0603=1608 0805=2015 1206=3216 1210=3528 5050=2020

[@Okurka.]

5050=2020 ?

[@dlinnoedlinnoe]

2020=5050 :)

[@tonybrock5288]

Yip, in hindsight you're correct ;-)

[@ELECTROHAXZ]

Here before 1k views :) still a bit late, but not too bad

[@pinterelectric]

Limp

[@rofo88]

first

[@JulianIlett]

Yes :)

[@jort93z]

Even a surface mount mosfet? Will the femto version be as good? Also, i doubt it will work with just a syringe. I think you'll just compress the air and nothing will happen. Honestly, i personally think you should just get an smt stencil(JLC pcb makes those too), thats a lot easier. You can do the whole board all at once in a couple seconds using that without any precision on your part. All you have to do is align it properly and then spreading he paste all over it.

[@JulianIlett]

Ah, yes, the MOSFET and transorb diode are still through-hole. The legs of the MOSFET double up as a connector :)