I was in poundland today and i noticed they'd got their halloween stock and not much halloween stock. I don't know if this is just last year's or they've got some new stuff in, but they put it out on display. The place has been very sort of empty. This year, because of new stock because of the covert thing, and also because of the brexit shenanigans, all the politics with trucking and stuff - but these are a set of 100, led string lights.

I got uh, they had a choice of code, white or orange leds. It's a shame: they don't the purple ones, they were just fantastic, they usually do, but a smaller set it'd be nice if they did the purple ones in a really big set like this, which is a hundred leds. So it's designed to take three double a cells. Is there a resistor in here or is it some circuitry? Is there a timer, so you can get this off? Oh, that is not coming off easier.

They glued this on. Oh, no, it's off uh. There is no resistor or timer. It.

Just is a little on off switch. Okay right. I shall power these from my bench. Power supply actually i'll put the meter on.

We can actually measure uh what voltage light up. I'm surprised i've not got a resistor with three double a's, because that would be 4.5 volts. That's going to push quite a lot of current out. We can test that we can run it up to 4.5 volts and see what current it is taking.

But initially i want to see the voltage here, so i shall stuff the red lead up there, posh clever, really sophisticated and the black lead up here currently at 1.57 volts in the power supply. Let's see it watch what point the light up. This is a point. I could actually uh turn the light off and we could take the exposure off and we can see this together.

I have watched sort of level the light up at so the light is going off. Oh, that's very dark uh right that wasn't all that clever because hold on but uh it will provide its own illumination uh, just starting to glimmer into life at oh hold on i'm gon na have to screw it up. Uh hold on 2.39, that's pretty good uh! So they are just starting to glow at uh, just under four volts, which is good for running the nickel metal hydrides, because they will last a long time at 2.5, volts they're, a decent tents, they're up to five milliamps at 2.6, volts they're up to 30 milliamps 2.7, volts they're looking actually pretty bright for normal use, and that suggests that you know run them off. A couple of doubles wouldn't bear, but that's 88 milliamps.

Now i'm at 123, milliamps 2.8 volts, um yeah and it's starting to swamp out a bit right. So i'm going to bring the light back one moment please, the light is back okay. So let's continue now you can actually see them against the studio lighting. So at three volts that would be two double a's, but that's not two double a's.

The current draw is 290 milliamps if i turn it up to 3.6 volts, which would be a set of nickel metal hydride cells, that is at 829 milliamps. That's quite a lot um, as i turn it up. I've set this limit that cut the limit at 4. Volts, this is going to absolutely yeah.

This is going to using the three double-a's seems a bad idea, but anyway, that doesn't really matter, because, to be honest, this is just a great way of getting these strings of led lights and, ultimately, you and me can modify stuff. We can actually hack stuff. This is something that would lend itself well to being modified to usb power, just by adding say a 10 ohm resistor in series with each lead and just connect it to a usb lead. I might do that right.

Tell you what i'm going to do that one moment please and begin the hack, so a typical little usb lead you get with random products, i'm going to cut the end of it off and i'm going to strip it. It's probably got super thin wires in it. I think this is the type that just has the positive and negative. That's even better.

Is it going to strip with that one? No! Is it going to strip this one? Is it going to strip everything off? No, that's it! It's got the two wires red and black doesn't necessarily mean they are red and black, but we'll find out and put it together. I could test this. I shall just uh strip a little bit like that, a little bit like that, the insulation stretches and then retracts back once it's heated up. It should actually with the solder.

It should actually retract a bit further out the way. It's not very good. It's it's very chewy. It's not ideal for stripping! That's okay! It's fine! We shall resolve that issue, so i'm going to twist those together, i'm going to get a little bit of soda and i'm going to tin them.

I could zoom down for this. It probably would be better to zoom down for this, because i'm kind of far away i've got the helping hands here. This is also good. I should get this black thing out the way the black battery holder, so i'm putting a little bit of soda on this.

The wires are very thin, but this isn't uncommon. They save money by using super thin wire. It also kind of limits the current to the device being charged to a degree right taiwan. You could either mark the key wires by working out, which is positive.

To this end put snake to this end, but i'm just going to chop them, chop them and then strip them and i'll show you how to identify the polarity. So i'm going to use this little generic wire stripper draper brand wire stripper very common type. People ask: why do i use the universal automatic wire strippers and the answer is with some of these wires that just the automatic wire strippers actually damage the wires. So now that i don't know which polarity these wires are, i'm actually going to get a little lithium button cell, which is about three volts dab it on nothing, light dab it on the other way round, nothing lights, because i this actually that dead light.

But this is a flat cell. Let me see if i can get a a better cell. Maybe we should get rid of the flat cells yeah, it's making them glow. You may not see that, but it is making them glow.

That is the correct polarity. So the one with the big flat surface is the positive, so i shall actually just use a sharpie since this black wire, i'm just gon na color, the copper it's gon na it'll come off when i start uh soldering it anyway, resistors i'm using two quarter. Watt 10 ohm resistors, which are ample for this batteries out of the way so i'll crop these down to about just over eighth of an inch about three millimeters, and then i shall put one into here and i shall pre-tin it with some soda. And then i shall get one of these leads and i shall solder it on.

I've pretended these as well, so i'm just really just flowing them together again flowing fresh, so drawn be handy, but there is a limit to what you can do with two hands. I shall do the same with the other resistor. This is quite a nice modification because it means you can just run the leds guilt-free. You don't have to worry about batteries.

They'll always be the same intensity if you're really get through a lot of lights, you can also make it with a little adapt to these resistors and connectors, and you can just plug in whatever lights you want, and it means you can change them very easily. So now i'm going to sort of positively down here, i'm saying positive, you just never know. Sometimes the chinese manufacturers make red negative and black positive. They just sometimes do that.

I'm not sure why they do it. I guess. Ultimately, the people in the factories aren't necessarily super devoured technical. So, as you crop these down now before soldering these on, i'm going to put a bit of heat shrink over them, so i can pull it back over the resistors.

So i shall cut this convenient bit that i've looked out in half and i shall slide it over before tinning these wires and sticking onto those resistors, and that will be it. We can plug it straight in and see what happens. I could check polarity of that lead, but i won't i'm going to take a chance that it might actually be right this time. So, let's clamp the positive lead resistor here and i shall tin the lead with the red sharpie on it, which is the positive and flow it on.

Don't worry if you forget to put the heat shrink on before soldering uh you're, not the first to do that. It happens a lot worse when you're dealing with huge multi-pin connectors. It can be just fatiguing when you you get to the end of a job and you're just about to put that connector lid on you realize that the bit that was supposed to be already isn't, and now you have to basically remove all the wires and start From scratch, that is a demoralizing experience, but something most technicians have experienced at some point and if you get involved in doing technical stuff, you too will experience the trauma of that one day. Hopefully it won't be a huge mega multi-core.

That's the more connections. The more time it takes the the worse that is when you do that now comes the negative connection and before i put the heat shrink across i'm actually going to test this, i'm going to plug it into a usb power bank. I've just spotted one, a little cheapy as strangely and iconically a pound, landy style, one in pink right will it work and what sort of current will it be so make sure i don't short these resistors together. I shall just plug this in.

Hopefully the leds will light. The leds have lit nice. That's excellent! Now i shall put the heat shrink down over the resistors, and this is where you could use a heat pen as i'm going to use part of my soldering station or if it's all, you've got. Yes, some people do use a lighter or some other source of hot air uh.

Just to shrink this uh heat shrink, sleeving down heat, shrink, sleeving's a really useful stuff. It provides a nice finish to things as well as insulating them. That looks neat. I wonder what current it's drawing uh do.

I have a little current analyzer. I i do, but it's not through here one moment, please. I have fetched it to resume the video something worth mentioning. If you want an extra sort of rigidity or ruggedness, you can actually put another bit of wider heat shrink sleeving and put it over this part first and then slide it back and cover both those connections.

It just makes it super rugged and neat ideal if it's going to see a lot of use like for say, for instance, lights on the table at a party, i shall plug my little rueden parameter into this. What's it going to be, we could try calculating it. First uh: it's dropping two volts 20 milliamps hundred milliamps at 20, ohms 100 milliamps ish, 114. Milliamps.

That's perfect! That's going to good! Well! That's going to give a good long life, because that's roughly just over about 1 milliamp per led and that's a nice intensity. That's pretty good and you'll get a very long run time, even off a small power bank like this um anything else worth mentioning here. You also once you've hacked it like that. You do get to keep your uh your little uh battery holder.

So that's a little bonus extra thing. So, yes, the poundland lights, good donor lights. It's a really nice color! It's a really soft um tangerinish orange! It's got almost a pinkish tinge to orange. It's because it's phosphor it's much richer than the traditional orange ones, and with this modification uh just running off a plug-in power supply or power banks uh and a hundred milliamps, it's going to keep even big power banks awake most likely, which is good, uh running them Off these, you can just basically leave them on for as long as you want, because the power consumption is effectively 5 volts, 100 milliamps, say half a watt for the whole lot.

That's uh, really nothing! It's a negligible amount, but there we go the synopsis here. This summary is that the poundland lights - i wouldn't actually use them with this battery pack because it's going to overdrive them. But if you do that little hack with two quarter - watt 10 ohm resistors and an old usb lead salvaged from some other product that are just bought from poundland. Then you can basically make yourself a decent set of uh of lights.

That can just be left on all the time and they're a nice color they're, pretty good, so actually worth it just for the leds. They were also pretty well matched um, which is nice because it means that one's not hogging the current. So that's a good result.