Good afternoon all new printed circuit boards from jlc pcb i've already broken the seal. So let's take a look at what's inside here here they are so i've called this one. Current limiter, current limiter, uh yeah. Let's open them up and take a look at it and see if it works.

It's a bit of a strange one, this so yeah. This is another power pcb i've used both sides of the board and i've largely kept the copper areas complete. The top side of the board you can see goes to this top connector bottom side of the board goes to that bottom connector. So what are these components? Well, the two connectors on the end are these things: their banana plugs or banana sockets, oh in yellow as well.

How sensible is that and um i'll get the spec for these? I bought these on ebay, so we've got an in and an out as far as current flow is concerned. Oh well, i can give you some information on these. They are made by deltron in the uk, deltron uk made so they're, probably quite old, because i don't know whether we make this sort of thing anymore here in the uk, but yeah deltron, so i'll get the ebay listing and we'll see the uh spec number. So this is the ebay item.

Ten of these deltron five, seven one. Oh seven hundred four millimeter yellow pcb banana socket. I paid seven pound fifty seven for these ten, which was rather a lot now. If you scroll down i'll scroll down, you can see this one here.

The black one is five, seven one o one hundred these are o seven hundred, so it looks like they change the part number for the different colors uh, but that's the socket that i selected and that's the one that's going on the pcb. Let's solder, these two connectors in nice, hot iron, uh 400 degrees, because these are not spoked. These pads they're direct connected to the copper, so we're gon na need a fair bit of heat to get them soldered, but that seems to be working now. The two pins on each connector are, of course, connected together, because this is just a single connection and then the two pins on this connector also, of course connected to i'm just rambling really to fill the audio track, while i'm soldering these connectors.

Okay, they're done so. That's the connectors soldered in now. Have you guessed what these components are i've, given you plenty of time, have you worked it out by now? Okay, i'll, go and get them and we'll see if they fit well. They are these h7 car headlight bulbs.

Now the question is: will they fit into the pcb and really my longer term question is: how long is this pcb going to last getting quite hot, having 55 watt headlight bulbs directly inserted into it? Yes, that's going to be quite interesting, so here we go. The big question is: do my bulbs fit in my slots? I did take some time measuring them with the electronic caliper. Let's bring the camera down. For this make sure my camera cable doesn't hit the soldering iron.

Okay, i'm not going to touch the glass on these because i don't think you're meant to are you right here? We are then does that fit in there? Yes, it does that's pretty good and it's a nice tight push fit now. I'm hoping i don't even have to solder these, because actually i had great difficulty soldering these. In fact, i couldn't solder them. I failed to solder them i'll uh go and get the other two bulbs i'll just put this one in actually.

So this one goes and that's why i sort of drew this. These l shaped on here just to sort of simulate this i didn't, do them as cutouts, because well it would have taken too long to work out how to do that. Yeah. These are a nice tight fit.

I'm not sure that it's the width of the spade, because i think these are quarter inch or 6.3 6.4 millimeters 6.35. Isn't it i think um, but i made them. I measured these as 0.8 thick and i actually made the slots. 0.8 now i don't know whether, when these are cut with the routing bit, whether they compensate for the coating uh, the copper that is deposited down in the hole and then, of course, the lead solder coating that goes on there.

I don't know whether they compensate for that, but anyway they're a nice tight, fit so yeah, that's quite good right i'll get the other two bulbs and you'll see what i mean about not being able to solder them so in the shed um in line with the Solar panel i've got this contraption, which is essentially the same as this here i put two bulbs on two wires going to banana plugs and then they're converted to banana sockets by these female to female converters, but i'd recently put another bulb across them. So i've got three bulbs, but even these light up quite bright, and so i wanted the option for four bulbs: that's what i've done here now you'll see. I have been able to solder the wires to this h7 bulb so i'll. Just disconnect that one! That's an older type uh, which i don't know where that came from, but these ones i just couldn't solder to them, and if i bring the camera down you'll see what i mean: they're, not actually soldered.

All i've done is i've passed this fairly thick copper wire through the holes in these bulbs and just put a blob of solder on the end. So that's not actually soldered, because that rotates on the wire, but the wire is thick enough going through the hole in that spade that um. It makes a reasonably good connection. Now these two bulbs are identical to these because they came out of the same kit, which i bought from lidl.

I think it was. They were selling them off cheap. I think it was uh a pound or two pounds. Actually, yes, there.

We are two pounds for two bulbs, so i now need to resurrect these two bulbs, because i haven't got any more of those kits. So i'm just going to cut these copper wires and try and thread them back out through these holes and then slightly clean up. But i mean i, i tried to solder these with the hottest iron i've got and they just would not take. So i don't know what this metal is or what it's coated in, but it just couldn't be soldered to at all.

So i think i'm going to have to cut these solid wires close to the bulb i'll, try not to damage the bulb in the process. I don't want to break the filament by doing that and then that, if i can find my pliers yeah, this piece of wire with its blob of solder, should just pull out of the hole in this bulb. There we go and that reveals the unsoldered blade. You can see little bits of flux on there where i attempted to solder to it, but it didn't take at all so i'll cut the rest of this off and you can see that these wires are actually soldered on to the copper, bust bars and the salt.

Just hasn't had an impact on the spades of these bulbs, so i'll cut all this away, get these bulbs out put them in the pcb right. Oh the sun's coming around, let's uh lower the blinds a little bit. That's better right! Push these into the pcb, and i think this will work just as a push fit, because i tried once before. I don't know whether you remember to have push fit arduinos, but i think the problem with that was that inevitably you're going to end up with some of the pins sitting, midpoint in the socket and not making a connection.

But of course, here you've only got two pins, so one is effectively pushing against the other. So these should make quite a good connection and there's something like eight amps goes through this board, because the maximum i've seen from the solar panel under full sun is eight amps, so yeah that should work. Fine, okay, i'm going to take that out to the shed give it a try, see what it does now longer term. Of course, this is going to be quite tested by heat, so we'll keep an eye on this over the longer term to see whether the heat from these bulbs with four of them in parallel, they probably won't glow that bright, but they're still going to get quite Hot, so i wonder how well this board will survive that very neat for that much neater than all this mess right.

Let's take that out to the shed and give it a try, there's the pcb in situ in the shed. Now, what it does is it simply intercepts the incoming solo. I've got on the positive, but it wouldn't matter if it was on the negative. It's just a well, it's a non-linear resistor.

This is why i've called it current limiter. The sun's gone in at the moment. There's a big gray cloud out there, so they're not lit up but um these lamps uh, the filaments, have a very low resistance when they're cold. So at the moment this is almost a dead short and that's good, because it means that all the current from the solar panel is going through these very low resistance filaments and into the battery.

This is the battery pack there. This is a voltage controlled relay which turns on the load once the battery pack gets up to 28 volts, not sure if you can read that, but it says 26.3, so i'm just waiting for the sun to come back out and when it does, these will light Up the sun briefly came out when i first connected this and they light up not particularly bright, because there are four of them now in parallel and the maximum current i've seen from the solar panel when the sun just comes out, and the panel is cold, it's About eight and a half amps, then of course the panel warms up its voltage drops the power level drops and the current going through here, stabilizes about seven and a half amps. I think so. Not only is this board gon na get um about eight amps put through it, but it's also gon na get quite warm.

Let's go and have a look at the sky and see when this sun is gon na come back yeah, it's quite gray and overcast at the moment. But there is some blue up there, so we should get the sun back at some point uh, but i think it's going to be just a bit of a waiting game. So i'll come back when there's some, so it's raining now now the reason i originally put these bulbs in the circuit. I don't really need them now, um, because the maximum current from the solar panel.

Well, i think if you look on the back panel, the back of the panel, it's rated at something like 11 amps, but i've never seen that i've only seen about eight and a half amps um previously, and i don't know whether i can tilt the camera. Yeah kind of this bms was a smaller one and the charging current for the battery was 10 amps. So i didn't want the full current from the solar panel, not that it actually gets up to 10 amps. But i wanted to limit that current going into the bms, the previous one, that could only do 10 amps.

This one can take 20 amps in and 40 amps out. So it's a beefier bms and i mean i always put my hand on it just to see. If it's getting warm and it's never any more than just barely, not even warm, just not cold um, but i've just got used to having these bulbs in the circuit, and i just really like them - and i just wanted to sort of make this a little bit More uh neat uh, just babbling at the moment, waiting for the oh, the sun is there. Actually, i can see some sunlight, but i don't think it's full strength, sun.

I think it might be hazy sun, because these aren't lighting up, there's four amps actually coming from the solar panel. I'll just go and have another look at the sky. That's the sun! As seen through a welding glass. I'm not even sure you can see the disc of the sun there, but there is some.

Oh, let's take the welding glass off. There is some blue now emerging over the top of the hedge, so we are going to get some sun fairly soon. I've just waggled one of these bulbs out so that i can remove it from the board. If i choose to the tightness of these spade, terminals in the board is absolutely perfect.

I've got that spot on because they're tight enough that they're going to make a good connection. I have seen these light up briefly. The sun briefly came out, but i wasn't filming it at the time, but it's coming soon. Don't worry i'll get a shot of it.

So that should be fine, even if it's just plugged in loosely like that, it should be in circuit. The sun is starting to come out of some hazy cloud cover. You can see the current climbing up there. Four and a half amps uh, the lamps at four and a half amps still aren't lit.

No, the filaments are still cold, can't see any even a dull red glow there. Oh the sun's coming out even more 4.9 amps. 5 amps, no, they still don't light up at 5 amps interesting. I thought you'd like to see the sky again.

I can't see what's going on on the display of this phone, so i can't really see what you can see, but that's the sun and that's the cloud i'll. Take the welding glass away, yeah the blue, the sun's just above the camera. There don't shine it straight into the lens, but the blue is definitely coming our way. We're gon na have the sun soon.

Ah, i wasn't watching it's now risen to seven amps from the solar panel and yes, there is a pleasant red, fairly dim glow. Coming from the bulbs, so i'll just wait until the sky completely clears, and we get up to about eight and a half amps, which i think is the maximum. This will get up to i'll. Just put the camera in the holder, like so uh.

I thought that would make a nice shot. That's with the uh shed door closed and it's now 7.8 amps to the naked eye. These are orange they're, a sort of um they're, not bright by any means they're a dim glow. They look a bit brighter on the camera, but that's perfect because that's not really current limiting.

Until we get up to the sort of eight eight and a half amp range, then they light up. I quite like them as a sort of visual indicator and that pcb actually works perfectly well. These discs hot, not so hot, that i can't touch them, so they shouldn't be putting too much heat into the pcb. They might be hot underneath because the filaments are spot.

Welded directly to these legs, but no that's not burning my finger. That's not hot i'll leave my finger on the protruding spate terminal. No, there isn't much heat going downwards. Maybe they haven't been on long enough but yeah.

I don't know whether that pcb is going to suffer unduly because these bulbs just aren't going to get very bright. I think, actually i can push this one back in because i, oh that is a little bit warm um. No, i don't think it is warm. Actually.

I think it's just pressing into my thumb yeah. I just like this with the full complement of four h7 bulbs. Now, of course, as you can imagine, i had to draw the footprint for the h7 bulb myself, because nobody has been crazy enough to put an h7 bulb directly into a pcb, so nobody's drawn a footprint for this thing apart from me and there it is with The shed door open, so we've got a bit of daylight coming in that's almost exactly eight amps on the solar current meter. So that's it that's my uh h7 light bulb uh current limiter pcb with four millimeter banana plugs.

I'm really thrilled with that. Actually, i think, that's wonderful and the fact that these don't need to be soldered in is even better, so yeah, i'm very happy indeed, cheerio.