I used such a diode years ago in a frequency inverter. That was the age before TH-cam! That time I understood the function of such diode. It's a sort of MOV.
i've used the P6KE18CA for stuff in my car. Basically it "is" two z-diode coupled together. our 5.7 kw peak solar roof installation is many cells in a row, because so you get better conversion rate to 230V AC, even if on low light. AND you can take smaller wires because high voltage low current.
Hi Julian, in case you really need protection, a single direction transil will help you better, unless you don't care full reverse voltage on your equipment. Transils work much like varistors (MOVs) but are much faster and they can also provide assymmetrical polarity (unless bidirectional ones used). It will take only sertain ammount of energy untill it gets toasted, so these components meaning is to get a fuse blown before the rest of your circuit since fuses are quite slow acting elements. Good luck :)
FOCUS you Femto! I really appreciate your using JLCPCB, because of you and some other youtubers I recently got my first boards spun up. Thank you for your content!
I also just got my first PCB printed. It's for a tiny LED matrix with an SMD chip. Too small for perfboard... Just got it delivered and intend to make a short video about it soon...
You may find spray conformal coating a little easier to use and potentially much cheaper in the long run. The type of UV in your flashlight is also perfectly safe to expose your skin to. Also try slathering a load of thick grease over the battery terminals and that should help prevent corrosion.
Those bi-directional diodes are used in magnetically latched contactors to suppress back emf when applying a supply to the contactor coil in either direction 👍
If you don't have access to the fancy anti-ox stuff, Petroleum Jelly works really good at keeping your terminals clean. Clean the terminals and leads then slather it on.
As far as I remember, the “A” in both versions signifies the tolerance of the nominal voltage. It also looks like the board marking with the cathode line might be intentional. You might be better off using a non-C version that would provide some protection against reverse polarity (less than 1 V). Now with the bipolar version you allow full 33 V of reverse direction voltage before the TransZorb protection kicks in. The rest of the circuit got damaged way before that! And one little note about the power handling: The P6K33 stands for 600 W as you stated. Could read as 0.6 kW as the P6K... There are also parts 1.5KE that are 1.5 kW rated power capacity (sub-millisecond duration). All this from the top of my memory. I used to apply those way back when.
I have also noticed little wisps of smoke or vapor coming from larger amounts of this type of glue. Not 100% sure but I think it is a chemical reaction of the glue to the UV light. 15 seconds seems to work when hardening the glue.
Last fall a piece of the gasket that seals the hood like device on the front of our Class A Motor Home came loose. It kept sliding off every time I checked the oil, which, caring for my engine condition, I do at every fuel up. So when we got to our winter quarters, I drove up to a local hardware store, and the fellow behind recommended this tube of stuff to fix it. I took his recommendation and bought the stuff. A few drops of it, and the gasket is fixed, so I am left with a nearly full tube of the stuff. Well about a month later, the handle on the microwave/convection oven came loose, in order to fix it, you need to disassemble the entire door, not a chore for an old man, so I took the black stuff and glued it back on, it is still working just fine. Well this summer I built a nice little ghost detector for my niece, who is into that crap, and I needed to cover the resistors and wires that were exposed, my mind turned to that tube, and I used it to cover the top, yep still working great and the stuff is impervious to water, it goes on and really looks like wire insulation and dries in just a minute or so. The stuff is made by 3M called BLACK SUPER WEATHERSTRIP ADHESIVE. Smells almost as good as that glue we used to use to make models back in the 60's till they banned it because some of the bad youngsters were sniffing it to get high. If you don't mind the BLACK part, give it a try, if you can get it over there, I am sure you will not be disappointed.
I know you were fretting about the obscured LED, but I like how turned out... it lights up the components and wires. :) Maybe for the next run, you can get the white boards to reflect the light even more.
The outside croc clips Mr Ilett a bit sloppy , I expect better, years ago when I was an apprentice,when finishing a job where battery clips were involved, we had to cover the joints with this red translucent jelly type stuff,I can't remember it's name, but it kept them like New.
Big battery installations (think telephone office with phone booth size batteries) use NoOxide brand to prevent corrosion. Not sure how that would work when exposed to the weather.
You should have a resister in series to give a bit of protection to the poor device. I had a 0.5R resistor in place of what should have been 5R. During lightning testing I kept seeking little flashes trying to get a better view as you don't want to get too close, we did one last hit and the tranzorb left the box in one bright flash and a bang. 0.5r was not limiting the current enough from the strike pulse.
I believe marine shrink wrap has adhesive lining the inside. Not sure if it comes in a clear plastic, but that might serve as extra protection on top of the conformal coating?
And now, Weather watching, brought to you by Julian Ilett and the PWM5 Femto! Love how that UV conformal coating worked out. Hopefully you can find a cheaper source, as $.50+ per piece is not trivial for a $20 finished product if one decided to produce them for resale. Gotta love it when a plan comes together ;)
Seriously? 0.5 is 2.5 % of 20. The biggest problem isn't the money, but the time he spends applying the conformal coating (and soldering the components himself). Time is money, after all.
Good idea. My first self-built charge controller probably died by transient. Fried an INA219 chip. Unfortunately it fried it in such a way that it still had a working i2c interface, but returned an incorrect reading - leading the controller to conclude the battery was perpetually under-charge. When I found the problem the battery was so hot the plastic had started to deform and it was making unsettling bubbling noises.
little trick for the crocodile clips is to heatshrink the crocodile clip, maybe with 2 or 3 layers so they still have the clamping, but not the rough teeth. also, about the voltage indicator led, even for me watching the video its sometimes difficult to count that fast, wouldnt it be easy to just slow the second ones showing the .5 and .8V slower, so you can count them, and not guess them? oh yeah and do you have a link to the voltmeter box you showed on top of your batterys, i bought some from amazon, but they often have big tollerances, or are just like half a volt off^^ thx
What you want is some RTV Silicone 705 from aliexpress. It's crystal clear. If you want white then RTV Silicone 704 type A and black is tybe B. Lovely stuff, waterproofs easily and very inexpensive. Works for potting stuff in small blocks of it as well.
Yes it does get quite warm when you cure it. Couldn't you run all the leads off one end and dip the board in a pot of resin? You can get it in very large bottles.
Julian Ilett+ I don't know if you seen my last post , but I would try some UV Protectant Polyurethane mixed with hardener, dip the PWM5 Femto into the mix and let it firm up on its own. I think in time that glue will break down with constant every day UV hitting it and we're trying to protect it and it cost much less and will seep into everything and seal it hard as a rock.
Hi Julian, I used UV curing glue on some solar light connections outside, they didn't last, yours might if you over wrap them and plug the ends. From the size of your PCB I was wondering if 18650 wraps might be a good option once you have coated them? They come in a clear version so you can still see your LED.
I use UV hardening acrylic resin all of the time, because it is clear the UV passes trough it all of the way to the bottom. It is not a real glue because it cannot be hardened between two objects. (unless on is glass or UV conductive plastic) This looks like a suitable use for the stuff. The sun will finish any unhardened spot soon enough. I charge such batteries with 13.8 Volts.
3 minute epoxy sets too fast, would not creep down into crevices well. Use at least 15 minute epoxy, and put a transparent tape border around the PCB so instead of epoxy running off the end of the board, it fills in well. Once the epoxy sets, the tape will peel off fine so long as the epoxy was touching the sticky side rather than the back side of the tape. Granted, UV curing is better for those of us with a short attention span who want to see the video stay continuous, but meh, this did not need epoxy or a conformal coating at all, just to be enclosed in a weatherproof housing.
@@stinkycheese804 Those flooring epoxy seems like a good way to get a large amount of epoxy cheaply, and sometimes they cure translucent which may help see the LED. These also cure in multiple hours so it's easy to position them, get the bubbles out, add coloring or whatever. Also I found that mineral oil (release agent) and silicone chocolate stick mold works well in potting small electronics.
@@Ziplock9000 Look for local sources. Buying from Amazon is a bit risky because it may arrive damaged, leaked and all congealed up, you may get hazmat fees, or it may get seized by the customs.
How does that beat using it then replacing it if it fails? Seems like buying a new car and crashing it into a wall to see how well it crashes into walls lol.
10:57 right at the start of this footage of you UVing it, a big blob of glue disappears over the right/top edge towards the wires. This is probably the glue that ended up "running out the other side" later on. i think the surface tension starts to change as the glue is setting. Or perhaps it shrinks, which can squeeze unset glue out from the lower layers.
I think cast resin in some kind of plastic tube could be a good solution for this. If you sand the insulation of the cables near the PCB, it will also be a very good strain relief. In my experience its the only solution that is permanently waterproof, even when in the ground or submerged in water.
This would have been a lot easier with conformal coating spray. Look into MG Chemicals' conformal coating. They have acrylic (not good for exposure to UV), silicone (stays vaguely sticky in my experience) and polyurethane (sets HARD) conformal coatings in spray, and liquid.
I can remember painting audio crossover boards with varnish, I beleive yacht varnish is designed to be waterproof (and coat the edges of the pcb too as Andy Ward says)
Hi, are you going to be selling these? If so, would it be worth your time getting one of the UV nail curing stations, as it would help with the setting of the glue, due to better dispersion of the light (I think) Anyhoo, cheers for the video :o)
Ah yes, good idea - that would work. The LED was initially just a heartbeat - so you could see that the unit was still working - but then I added a volts indicator (whole volts only) - then I added the tenths.
I read somewhere (can't find it anymore, sorry), that humans can intuitively count to 4 or 5 without thinking about it. That is why I though about the long 5. You get a long blink, than it is followed by at most 4 short bursts. If you want to get fancy, you could use morse numbers... ;)
It has an extremely fast response time - datasheet says 1 picosecond www.littelfuse.com/~/media/electronics/datasheets/tvs_diodes/littelfuse_tvs_diode_p6ke_datasheet.pdf.pdf
Link wire is much more sensible. Commercial production uses zero ohm resistor chips only because the pick and place machines can handle them more readily, but a human can handle a wire link perfectly well.
I mean wire links are free (we all have bits of scrap wire ends), infinitely adjustable bridging length, and more easily handled by a human doing hand SMD assembly as Clive is.
I did a quick test once - the backfeed current is tiny because the individual solar cells act like diodes. 36 diodes have a forward voltage of about 18V - this is way more than the battery voltage.
No. If the battery voltage is below 13.5V, the controller will have 100% PWM. So the solar panel is connected directly to the battery. Would you connect your 18V power source directly to a 12V battery? No.
Given the recent trend for new words on this channel (which I heartily support), shouldn't a diode with no cathode be referred to here as a "Monode"? Maybe, because it is effectively two diodes, with their anodes invisibly joined, a "Quadode" might be more accurate?
Sorry to dissapoint, but "diode" is the false name to begin with (di-ode = 2-way-street), for the known electronic component, since a "diode" lets flows pass in both dirrections, but its false use is long established. The component he introduces here, is an actual "diode" after the real etymology of the word...
Testing TVS diodes in-circuit is risky. There's no simple way to tell whether the current is flowing through the DUT, or is flowing through the component(s) the TVS is designed to protect. This is especially true when the circuit is unpowered. Current can backfeed through an I/O pin's esd clamping diodes to the supply, overheating the esd protection on the I/O pin and causing it to fail open. Your part will still work, but now your esd protection on that I/O pin is compromised, and you'll likely never know it. 18 months later, your customer starts seeing really erratic and flaky system failures, and the test engineer just blames it on "junk parts".
A TVS will usually fail shorted, and when it fails open, chances are a visual inspection will tell you. The scenario you describe is not impossible, but it won't happen that often.
I'm not talking about the failure of the TVS diode. I'm talking about the components the TVS diode is there to protect, being damaged while testing the TVS diode in-circuit.
Wind turbines add another complexity based on my experience. Since the voltage and power output vary with wind speed, the charge controller needs to vary the load/resistance seen by the turbine. If it's too high, it can stop the turbine. If it's too low, power output is wasted. Would be a great addition to the femto.
Basically if one side spikes it will automatically send that voltage to the other side that can't take that voltage because it also has a zener diode (this package) protecting it from spikes? Basically this is a voltage regulator that doesn't allow any voltage under what you specify untill the voltage goes above that and then cascades the voltage to the other side? Or look at it like this, both sides can only take 5 volts, I install a 5.3volt variant of this and I spike side A with 30 volts not only will I ruin side A with 30 volts but I will also ruin side B with 25-30 volts because I just dumped my over voltage to the side that can't take it? I'm not sure I fully understand the purpose of this package because I've always used a zener to ground or power not sensitive side to sensitive side.
I'm puzzled too. A zener will forward conduct or reverse conduct if there's an EMP in either direction. So I would guess that maybe the devices shown are for ac applications where you could not use one zener. I would further guess that a fat zener would survive long enough to take out a fast blow fuse in series from the solar panel, disconnecting the circuit completely. Induced emp from nearby lightening strikes may briefly produce a voltage spike that can fry most (not all) semiconductors. But they usually have little energy, so a good design can dissipate that. A direct strike to an exposed connection is a different matter, which I don't think you can remedy with a small component because it carries a huge amount of energy.
It’s not the absolute voltage that is the problem. It’s the high differential voltage between the positive and negative circuits. The protection device clamps such a high differential voltage by conducting. The current flows via it and the energy is dissipated as heat. Once the voltage differential drops below the specified voltage, it stops conducting.
Ray Kent - twisted cables help, yes. Not easy to do everywhere, for example at the battery. Also if you are using a manufactured cable, it may not have twisted cores. Most cables designed for power applications are not twisted.
That "tiny bit of blue sky" is known as "English Summer". It is a curious meteorological phenomenon, but there is no cause for alarm as it rarely lasts for more than a few minutes. ;)
Surprised you didnt just use the old transformer manufacturing technique of dipping it in varnish to conformally coat it - seems like a lot of faff to blob glue all over it. I appreciate it may have taken longer to dry.
Very entertaining and pleasant video as always Julian. I do prefer to listen to a Brit or Aussie nerd. Yankees are too nasal. I should know - I am one. Also, I'm half Brit and half German. a wonder I don't hate myself, aye? btw... I think it's time for a bigger cutting mat there. Thanks!
You would really like to have the shortest possible leads on the TVS diode to minimize the lead inductance. A surface mount component as close as possible to the input cables would be even better, and best would be having the TVS diode on the case rather than the board, right after the fuse if there is one (there should be). Haha, it didn't occur to me that the board was just going to be hanging in the air! :-O
But isn't it best to put the TVS right next to the device that its going to protect? The battery could probably handle the odd spike whilst the circuit wouldn't.
Usually a TVS is put near the input on a board, which is what Julian has done, but TVS diodes are designed for ESD or fast transients and aren't designed for surge, which is what Julian mentioned (e.g. from nearby lightning strikes). To protect against surge, you might want a GDT (Gas Discharge Tube) like they have on telephone lines when they enter your house. The problem with handling surge events on your board is that they can be 100 Amps or more, so even if the protection device works perfectly, it will almost certainly destroy your board.
You can get 3D printer uv resin . Take it from a boat builder fiberglass is not waterproof if the core is exposed , you will get osmosis and it will separate the layers .
Alligator clips “bite marks”: Put two tubes of heat shrink around each “jaw” of the alligator clip, and shrink them.... no more bite marks, and the heat shrink is fairly grippy!! And if you if find you need the teeth again, an exacto knife makes short work of getting them off again 👍
Hey I got an idea ...... why don’t you put some heat shrink tube over the teeth of your alligator clips 😜 haha actually I stopped by because the title grabbed my attention. Tnx for the info 😊 take care! 73 from ve3hip in Welland Ontario Canada 🇨🇦
To mitigate the crocodrile bitting on the cable I usually put a bit of the shrink tube on each jaw as a bit of protection for what it holds.
I used such a diode years ago in a frequency inverter. That was the age before TH-cam! That time I understood the function of such diode. It's a sort of MOV.
Put some heatshrink over the crocclip jaws.
Moisture can wick up between the shrink tubing & the insulation of the wires. I'd get some of the coating over those areas also.
put some heat shrink tubing on the croc clip jaws
Yep came to the comments to say this too
i think he is referring to the croc clip jaws on the bench gizmo
yup, just to protect what your holding in them
You beat me to it! :)
Was going to say the same :)
i've used the P6KE18CA for stuff in my car.
Basically it "is" two z-diode coupled together.
our 5.7 kw peak solar roof installation is many cells in a row, because so you get better conversion rate to 230V AC, even if on low light.
AND you can take smaller wires because high voltage low current.
Hi Julian, in case you really need protection, a single direction transil will help you better, unless you don't care full reverse voltage on your equipment. Transils work much like varistors (MOVs) but are much faster and they can also provide assymmetrical polarity (unless bidirectional ones used). It will take only sertain ammount of energy untill it gets toasted, so these components meaning is to get a fuse blown before the rest of your circuit since fuses are quite slow acting elements. Good luck :)
FOCUS you Femto! I really appreciate your using JLCPCB, because of you and some other youtubers I recently got my first boards spun up. Thank you for your content!
I also just got my first PCB printed. It's for a tiny LED matrix with an SMD chip. Too small for perfboard... Just got it delivered and intend to make a short video about it soon...
You could put heat shrink on the crocodile clips to reduce the damage on wires
You may find spray conformal coating a little easier to use and potentially much cheaper in the long run. The type of UV in your flashlight is also perfectly safe to expose your skin to. Also try slathering a load of thick grease over the battery terminals and that should help prevent corrosion.
I didn't want to use a spray - it would get all over the connecting wires. Also, I'd have to spray it outdoors.
Julian Ilett You can also use regular nail polish, it works quite well as demonstrated by GreatScott!
Use clear nail hardener on it, it really works for waterproofing. JI.
Those bi-directional diodes are used in magnetically latched contactors to suppress back emf when applying a supply to the contactor coil in either direction 👍
If you don't have access to the fancy anti-ox stuff, Petroleum Jelly works really good at keeping your terminals clean. Clean the terminals and leads then slather it on.
As far as I remember, the “A” in both versions signifies the tolerance of the nominal voltage. It also looks like the board marking with the cathode line might be intentional. You might be better off using a non-C version that would provide some protection against reverse polarity (less than 1 V). Now with the bipolar version you allow full 33 V of reverse direction voltage before the TransZorb protection kicks in. The rest of the circuit got damaged way before that!
And one little note about the power handling: The P6K33 stands for 600 W as you stated. Could read as 0.6 kW as the P6K... There are also parts 1.5KE that are 1.5 kW rated power capacity (sub-millisecond duration). All this from the top of my memory. I used to apply those way back when.
I have also noticed little wisps of smoke or vapor coming from larger amounts of this type of glue. Not 100% sure but I think it is a chemical reaction of the glue to the UV light. 15 seconds seems to work when hardening the glue.
Last fall a piece of the gasket that seals the hood like device on the front of our Class A Motor Home came loose. It kept sliding off every time I checked the oil, which, caring for my engine condition, I do at every fuel up. So when we got to our winter quarters, I drove up to a local hardware store, and the fellow behind recommended this tube of stuff to fix it. I took his recommendation and bought the stuff. A few drops of it, and the gasket is fixed, so I am left with a nearly full tube of the stuff. Well about a month later, the handle on the microwave/convection oven came loose, in order to fix it, you need to disassemble the entire door, not a chore for an old man, so I took the black stuff and glued it back on, it is still working just fine. Well this summer I built a nice little ghost detector for my niece, who is into that crap, and I needed to cover the resistors and wires that were exposed, my mind turned to that tube, and I used it to cover the top, yep still working great and the stuff is impervious to water, it goes on and really looks like wire insulation and dries in just a minute or so. The stuff is made by 3M called BLACK SUPER WEATHERSTRIP ADHESIVE. Smells almost as good as that glue we used to use to make models back in the 60's till they banned it because some of the bad youngsters were sniffing it to get high. If you don't mind the BLACK part, give it a try, if you can get it over there, I am sure you will not be disappointed.
Nice Job, Julian! What a journey.....
I know you were fretting about the obscured LED, but I like how turned out... it lights up the components and wires. :) Maybe for the next run, you can get the white boards to reflect the light even more.
Why do you want to make current from solar panels in England? Make a rain water generator, that would be smarter. ;-)
The outside croc clips Mr Ilett a bit sloppy , I expect better, years ago when I was an apprentice,when finishing a job where battery clips were involved, we had to cover the joints with this red translucent jelly type stuff,I can't remember it's name, but it kept them like New.
Would that stuff they put over car battery terminals work?
Possibly because it's somewhat nicer to work in sun and partly cloudy than a downpour?
Big battery installations (think telephone office with phone booth size batteries) use NoOxide brand to prevent corrosion. Not sure how that would work when exposed to the weather.
Because the "rain barrel" is occupied making fish for fish and chips.
You should have a resister in series to give a bit of protection to the poor device. I had a 0.5R resistor in place of what should have been 5R. During lightning testing I kept seeking little flashes trying to get a better view as you don't want to get too close, we did one last hit and the tranzorb left the box in one bright flash and a bang. 0.5r was not limiting the current enough from the strike pulse.
I believe marine shrink wrap has adhesive lining the inside. Not sure if it comes in a clear plastic, but that might serve as extra protection on top of the conformal coating?
Have you ever worked with Gas Discharge Tubes (GTO's) or SIDACtors for over-voltage protection in the higher range?
And now, Weather watching, brought to you by Julian Ilett and the PWM5 Femto!
Love how that UV conformal coating worked out. Hopefully you can find a cheaper source, as $.50+ per piece is not trivial for a $20 finished product if one decided to produce them for resale. Gotta love it when a plan comes together ;)
Seriously? 0.5 is 2.5 % of 20. The biggest problem isn't the money, but the time he spends applying the conformal coating (and soldering the components himself). Time is money, after all.
Good to see the solar panel frame is still standing tall - it was only meant to last one winter wasn’t it? ;-)
could you series connect them to get protection at a higher voltage?
It seems you can: www.mouser.com/pdfdocs/Vishay_AN88451.pdf
Good idea. My first self-built charge controller probably died by transient. Fried an INA219 chip. Unfortunately it fried it in such a way that it still had a working i2c interface, but returned an incorrect reading - leading the controller to conclude the battery was perpetually under-charge. When I found the problem the battery was so hot the plastic had started to deform and it was making unsettling bubbling noises.
A spark gap hand held transformer like used for personal protection shockers might be a way to see if it will work by simulating lightening.
little trick for the crocodile clips is to heatshrink the crocodile clip, maybe with 2 or 3 layers so they still have the clamping, but not the rough teeth.
also, about the voltage indicator led, even for me watching the video its sometimes difficult to count that fast, wouldnt it be easy to just slow the second ones showing the .5 and .8V slower, so you can count them, and not guess them?
oh yeah and do you have a link to the voltmeter box you showed on top of your batterys, i bought some from amazon, but they often have big tollerances, or are just like half a volt off^^ thx
What you want is some RTV Silicone 705 from aliexpress. It's crystal clear.
If you want white then RTV Silicone 704 type A and black is tybe B. Lovely stuff, waterproofs easily and very inexpensive.
Works for potting stuff in small blocks of it as well.
Yes it does get quite warm when you cure it. Couldn't you run all the leads off one end and dip the board in a pot of resin? You can get it in very large bottles.
Julian add heat shrink to the jaws of your helping hands
Julian Ilett+
I don't know if you seen my last post , but I would try some UV Protectant Polyurethane mixed with hardener, dip the PWM5 Femto into the mix and let it firm up on its own. I think in time that glue will break down with constant every day UV hitting it and we're trying to protect it and it cost much less and will seep into everything and seal it hard as a rock.
I did read it. The problem with dipping, is that the coating will get all over the wires. Not sure I want that.
Okay, but you don't have to dip it, you can brush or drip it on and the hardener will assure all is hardened.
Would it be possible to dip the whole board in resin?
Just curious - what's the benefit of using the UV glue over one of those small waterproof enclosures you can get from China fairly cheaply?
Hi Julian, I used UV curing glue on some solar light connections outside, they didn't last, yours might if you over wrap them and plug the ends. From the size of your PCB I was wondering if 18650 wraps might be a good option once you have coated them? They come in a clear version so you can still see your LED.
I use UV hardening acrylic resin all of the time, because it is clear the UV passes trough it all of the way to the bottom. It is not a real glue because it cannot be hardened between two objects.
(unless on is glass or UV conductive plastic) This looks like a suitable use for the stuff.
The sun will finish any unhardened spot soon enough. I charge such batteries with 13.8 Volts.
The packaging on the diodes (the paper things) was polarised...
I wonder if they just don't want to change the reel at the factory.
I think the 3-minute epoxy could do a better job in my opinion.
Also a piezoelectric buzzer can make the counting easier in some cases.
3 minute epoxy sets too fast, would not creep down into crevices well. Use at least 15 minute epoxy, and put a transparent tape border around the PCB so instead of epoxy running off the end of the board, it fills in well. Once the epoxy sets, the tape will peel off fine so long as the epoxy was touching the sticky side rather than the back side of the tape. Granted, UV curing is better for those of us with a short attention span who want to see the video stay continuous, but meh, this did not need epoxy or a conformal coating at all, just to be enclosed in a weatherproof housing.
@@stinkycheese804
Those flooring epoxy seems like a good way to get a large amount of epoxy cheaply, and sometimes they cure translucent which may help see the LED. These also cure in multiple hours so it's easy to position them, get the bubbles out, add coloring or whatever.
Also I found that mineral oil (release agent) and silicone chocolate stick mold works well in potting small electronics.
Got a link to that epoxy in the UK please?
@@Ziplock9000
Look for local sources. Buying from Amazon is a bit risky because it may arrive damaged, leaked and all congealed up, you may get hazmat fees, or it may get seized by the customs.
How about submerging the device in water for 24hrs (whilst powered up)?
I did that with the original PWM5. I suppose I should do it again with the Femto.
How does that beat using it then replacing it if it fails? Seems like buying a new car and crashing it into a wall to see how well it crashes into walls lol.
@@stinkycheese804 I don't think it would be the equivalent of a car crash. I think it would be ok. It's the satisfaction...
put some vaseline/oil on around the clips at the battery to protect against the rust?
what about a epoxide resin coding for the PWM5 Femto?
10:57 right at the start of this footage of you UVing it, a big blob of glue disappears over the right/top edge towards the wires. This is probably the glue that ended up "running out the other side" later on.
i think the surface tension starts to change as the glue is setting. Or perhaps it shrinks, which can squeeze unset glue out from the lower layers.
I think cast resin in some kind of plastic tube could be a good solution for this. If you sand the insulation of the cables near the PCB, it will also be a very good strain relief. In my experience its the only solution that is permanently waterproof, even when in the ground or submerged in water.
This would have been a lot easier with conformal coating spray. Look into MG Chemicals' conformal coating. They have acrylic (not good for exposure to UV), silicone (stays vaguely sticky in my experience) and polyurethane (sets HARD) conformal coatings in spray, and liquid.
corrosionx lifts heat glue a little btw.
I can remember painting audio crossover boards with varnish, I beleive yacht varnish is designed to be waterproof (and coat the edges of the pcb too as Andy Ward says)
Hi, are you going to be selling these? If so, would it be worth your time getting one of the UV nail curing stations, as it would help with the setting of the glue, due to better dispersion of the light (I think) Anyhoo, cheers for the video :o)
I've used Transorbs for PLC designs since the 90s. They just work and work well. I scoff at MOVs.
to isolate boards from the elements outside i am just using some spray paint... it works quite good...
So how come you didn't fix the low voltage reading in software? All you needed to do is add +0.2v to the read value, then display that.
I will write a calibration subroutine in the firmware :)
Aren't there any other drop in regulators with more precision available? Maybe you could use some kind of voltage reference instead?
I was watching the uncapped pen and wondering when you would see it getting UV light.
If you had used a longer blink for a 5, it should be much easier to count.
Ah yes, good idea - that would work. The LED was initially just a heartbeat - so you could see that the unit was still working - but then I added a volts indicator (whole volts only) - then I added the tenths.
or a gap after the first 5 - like a tally count :)
I'll have a look at coding that :)
I read somewhere (can't find it anymore, sorry), that humans can intuitively count to 4 or 5 without thinking about it. That is why I though about the long 5. You get a long blink, than it is followed by at most 4 short bursts. If you want to get fancy, you could use morse numbers... ;)
Morse? No thanks - I don't need another look-up table!
Based on the title the first thing that came to mind was a device with a single lead. It's a funhouse inside my head sometimes.
8:02 onward - pointing the UV light at the glue dispenser a few times... oops.
encapsulate in EPOXY RESIN?
Wont water wick it's way up between the wire and the heat shrink?
I hope not - but only time will tell :)
I wonder what are it's advantage over Unidirectional Normal Diode?
It has an extremely fast response time - datasheet says 1 picosecond
www.littelfuse.com/~/media/electronics/datasheets/tvs_diodes/littelfuse_tvs_diode_p6ke_datasheet.pdf.pdf
Is it not the role of a coaster to keep fluids off your table? And is the glue not a fluid? That is a perfectly acceptable use for a coaster
His partner may be more attached to her coasters than to his anti-static mat - that was the vibe I got from the "brownie points" comment.
Precisely :)
Why are you using the link wire and not just a 0 Ohm resistor?
Link wire is much more sensible. Commercial production uses zero ohm resistor chips only because the pick and place machines can handle them more readily, but a human can handle a wire link perfectly well.
@@Rosscoff2000 Oh, that makes sense. But what do you mean by they are much more sensible?
I mean wire links are free (we all have bits of scrap wire ends), infinitely adjustable bridging length, and more easily handled by a human doing hand SMD assembly as Clive is.
@@Rosscoff2000 True, thanks!
Rosscoff2000 - Clive?! Wrong channel!
Do you not loose power without having an anti back feed diode.
I did a quick test once - the backfeed current is tiny because the individual solar cells act like diodes. 36 diodes have a forward voltage of about 18V - this is way more than the battery voltage.
Would this work with almost any power source. Around 13-18vdc?
No. If the battery voltage is below 13.5V, the controller will have 100% PWM. So the solar panel is connected directly to the battery. Would you connect your 18V power source directly to a 12V battery? No.
What about using hot glue for conformal coating?
Hot glue will just peel off when it is hard.
A fuse after the transient suppressor would help extend the life of it and protect underlying components.
Given the recent trend for new words on this channel (which I heartily support), shouldn't a diode with no cathode be referred to here as a "Monode"?
Maybe, because it is effectively two diodes, with their anodes invisibly joined, a "Quadode" might be more accurate?
It still has two terminals, they just both happen to be anodes. Maybe to reflect the symmetry of the device it could be called a "dioib".
Sorry to dissapoint, but "diode" is the false name to begin with (di-ode = 2-way-street), for the known electronic component, since a "diode" lets flows pass in both dirrections, but its false use is long established. The component he introduces here, is an actual "diode" after the real etymology of the word...
Maybe test the transorb protection with the electronic ignitor from a cigarette lighter.
Great information as usual!
Why can't you pot that module in ISOPON Clear-Cast Epoxy and Hydrogen-Peroxide as the catalyst.
Testing TVS diodes in-circuit is risky. There's no simple way to tell whether the current is flowing through the DUT, or is flowing through the component(s) the TVS is designed to protect. This is especially true when the circuit is unpowered. Current can backfeed through an I/O pin's esd clamping diodes to the supply, overheating the esd protection on the I/O pin and causing it to fail open. Your part will still work, but now your esd protection on that I/O pin is compromised, and you'll likely never know it. 18 months later, your customer starts seeing really erratic and flaky system failures, and the test engineer just blames it on "junk parts".
A TVS will usually fail shorted, and when it fails open, chances are a visual inspection will tell you. The scenario you describe is not impossible, but it won't happen that often.
I'm not talking about the failure of the TVS diode. I'm talking about the components the TVS diode is there to protect, being damaged while testing the TVS diode in-circuit.
UV Glue works best when you apply layer then you harden it then another layer and so on, like dentist's composite dough teeth filler.
add a wind power input to your device. would be great.
Wind turbines add another complexity based on my experience. Since the voltage and power output vary with wind speed, the charge controller needs to vary the load/resistance seen by the turbine. If it's too high, it can stop the turbine. If it's too low, power output is wasted. Would be a great addition to the femto.
Basically if one side spikes it will automatically send that voltage to the other side that can't take that voltage because it also has a zener diode (this package) protecting it from spikes? Basically this is a voltage regulator that doesn't allow any voltage under what you specify untill the voltage goes above that and then cascades the voltage to the other side? Or look at it like this, both sides can only take 5 volts, I install a 5.3volt variant of this and I spike side A with 30 volts not only will I ruin side A with 30 volts but I will also ruin side B with 25-30 volts because I just dumped my over voltage to the side that can't take it? I'm not sure I fully understand the purpose of this package because I've always used a zener to ground or power not sensitive side to sensitive side.
I'm puzzled too. A zener will forward conduct or reverse conduct if there's an EMP in either direction. So I would guess that maybe the devices shown are for ac applications where you could not use one zener. I would further guess that a fat zener would survive long enough to take out a fast blow fuse in series from the solar panel, disconnecting the circuit completely. Induced emp from nearby lightening strikes may briefly produce a voltage spike that can fry most (not all) semiconductors. But they usually have little energy, so a good design can dissipate that. A direct strike to an exposed connection is a different matter, which I don't think you can remedy with a small component because it carries a huge amount of energy.
It’s not the absolute voltage that is the problem. It’s the high differential voltage between the positive and negative circuits. The protection device clamps such a high differential voltage by conducting. The current flows via it and the energy is dissipated as heat. Once the voltage differential drops below the specified voltage, it stops conducting.
@@Mark1024MAK what do you think about doing all long cable runs as twisted pairs to reduce the induced differential?
@@Mark1024MAK you just explained a typical everyday one directional zener diode unlike the one in this video.
Ray Kent - twisted cables help, yes. Not easy to do everywhere, for example at the battery. Also if you are using a manufactured cable, it may not have twisted cores. Most cables designed for power applications are not twisted.
That "tiny bit of blue sky" is known as "English Summer". It is a curious meteorological phenomenon, but there is no cause for alarm as it rarely lasts for more than a few minutes. ;)
Ain't that the truth :)
The bluTak-solution for your crock clip is called heatshrink tubing ;)
Surprised you didnt just use the old transformer manufacturing technique of dipping it in varnish to conformally coat it - seems like a lot of faff to blob glue all over it. I appreciate it may have taken longer to dry.
Put heat shrink over your crop clips stops damage
Useful video
Put some heat shrink on your crocodile clips so they are "softer" but still grab the wire.
Julian, are you aware of what’s happening on Fran Blanche’s channel, I’m sure she would appreciate your support?
Yep, I'm talking to Fran behind the scenes - I'll do what I can :)
@@JulianIlett www.bbc.co.uk/news/amp/technology-44279189
moisture will get in to your pcb. it is called delamination. that is the reason why polyesters are top coated. to keep the moisture out ..
I put heat shrink tubing over my crocodile clips. Now they don't bite into the insulation.
Funny , the symbol on the Diode under P6 is a single Diode with cathode and anode, maybe the library maker used that as a silc symbol 😊
Isn't a diode without a cathode just an ode ?
Very entertaining and pleasant video as always Julian. I do prefer to listen to a Brit or Aussie nerd. Yankees are too nasal. I should know - I am one. Also, I'm half Brit and half German. a wonder I don't hate myself, aye? btw... I think it's time for a bigger cutting mat there. Thanks!
You would really like to have the shortest possible leads on the TVS diode to minimize the lead inductance. A surface mount component as close as possible to the input cables would be even better, and best would be having the TVS diode on the case rather than the board, right after the fuse if there is one (there should be).
Haha, it didn't occur to me that the board was just going to be hanging in the air! :-O
But isn't it best to put the TVS right next to the device that its going to protect? The battery could probably handle the odd spike whilst the circuit wouldn't.
Usually a TVS is put near the input on a board, which is what Julian has done, but TVS diodes are designed for ESD or fast transients and aren't designed for surge, which is what Julian mentioned (e.g. from nearby lightning strikes). To protect against surge, you might want a GDT (Gas Discharge Tube) like they have on telephone lines when they enter your house. The problem with handling surge events on your board is that they can be 100 Amps or more, so even if the protection device works perfectly, it will almost certainly destroy your board.
I just put some rubber sleeves on my croc clips !
You can get 3D printer uv resin . Take it from a boat builder fiberglass is not waterproof if the core is exposed , you will get osmosis and it will separate the layers .
"3D printer uv resin" is too brittle.
You could whip up a quick van de graaf generator, they're not very hard to build.
Alligator clips “bite marks”: Put two tubes of heat shrink around each “jaw” of the alligator clip, and shrink them.... no more bite marks, and the heat shrink is fairly grippy!! And if you if find you need the teeth again, an exacto knife makes short work of getting them off again 👍
I wrap a layer of insulation tape around both jaws of the crock clips on my helping hands to prevent them marking stuff they are holding.
I would pot not conformal coat
hmmm my solar panels here in Hawaii get up to 35 v Voc
I just use a large lump of bluetac and stick the whole device to the bluetac and to the bench
Thank Ernshaw the God of Yorkshire!
Hey I got an idea ...... why don’t you put some heat shrink tube over the teeth of your alligator clips 😜 haha actually I stopped by because the title grabbed my attention. Tnx for the info 😊 take care! 73 from ve3hip in Welland Ontario Canada 🇨🇦
5:50 Just put heat shrink on alligator clips
Haha, everyone said to use heat shrink tubing! But you are a BlueTak guy!! Guess what, lol.
Fred Astaire, Ginger Rogers and Tommy Dorsey, eh? You forgot Glenn (Miller). :-)
A strip of elecrtical tape over the jaws of the crocodile clips will help prevent them from biting into the wire insulation.
Or shrinking tubes
These have been out for years.)
Anti emp protection for car
Yes blame the weather.