Simplest solar light possible, using old phone battery.

in a recent video I was taking a look at this little per bag with that solar panel on it and I couldn't work out why what looks like a real solar panel was putting out so little current I'll just put this out the way at the moment it's just a bit more interesting and I noticed that if you squeezed I thought it was just this metal films that you you know on a solar panel you get these of metal strips that make connections between the panels and I thought it was something to do with that which is hidden under a black tape in here so I squeezed it and the current did increase and I went outside into the sunshine to give it a good chance and it was abysmal it was like really low current and I've worked out why you see this had a front laminated onto it and he did that up and I peeled it off and underneath this is a very flexible circuit board material with a the silicon and that is proper silicon solar panels themselves which is just kind of disappointing because they've been ruined basically and they've been coated in what can best be described a set of polymer or silicon rubbery type stuff they you can scratch it but it's very hard to get this off and they've been coated in that to put them basically and then the front has been laminated under the serve matte film which just gives it extra rigidity strength and sort of resistance to abrasion in the front but what's actually going wrong here is that right where it goes onto the tape you can see the sort of piles of cracked and I'll show you that I'll actually crack this because this is unrecoverable so if you watch this solar panel here if I flex it very slightly you can hear slight cracking but if I flex it right here in the middle let's see if this actually shows it usually shows it's not showing so that is actually fracturing the silicon is fracturing but it's not showing at all there is a slight hint of the weight there I was hoping it was going to do what it usually does and I can see the cracks actually it was going to create little quite craze lanes but they are visible to me but they might not be so visible to you that's it let's do it really seriously then and then you'll probably see it no it still doesn't show so even though these panels are kind of cracked and broken don't only takes one or two actually ruin the whole cell that it's not really showing up so that is the weakness that's why it was crap unfortunately and it's a shame because as I see it's got a decent amount of silicon cells in it and they're just very brittle and this is just too flexible it's too easy to flag sentence it's been crushed in the postage which I've just thought I'm bout to do a project I'm just going to cut these wires off and reuse them so that's a shame but it has at least put me in the mood for a sort of project it's also put me in the mood for vile acts su-gyeong gwah which is the completely the wrong pronunciation of this Korean drink which is called sweet cinnamon punch and this was sent to me by Simon along with some other Korean stuff from within the UK so I'm going to open this up or before open up let's look at ingredients the ingredients are water cinnamon sugar dried persimmon and ginger all natural ingredients they haven't even done a coca-cola and added caffeine who would say it I should say nice hiss that was a slight hiss there I don't think it's carbonated that's really nice that is like it's 30% sugar which is partly why it's nice but it's got a super strong cinnamon taste like cinnamon toast or or those cinnamon buns cinnamon the other thing that Simon simply said a few things but this one I would even try I don't think it's got no it says it says in the back biscuits big caramel and it's got the ad can't even pronounce that at all I wouldn't know how that's pronounced but it also then says in English he's all not included and these are late Corn Pops except we are there oh that's well soon good as our corn pops tender with cheesy flavored other enormous it looks like a huge chart actually but this one is apparently chocolate flavor breakfast cereal grid that is basically like a huge cocoa pop it's very very sugary coated in outside that is ultra sweet very nice I shall particularly those later on but not the whole bag well not right now I'll just piece I'm gonna I'm gonna need bit more I'm gonna need the whole thing anyway now started mastic good eating noisily let's say it being a new pattern because we're gonna do a project on a while back I did a project where I used a mobile phone battery on the back of a standard solar panel and some secretary to me a dusk sensor so it turned a light on a night and it that I made that years ago and it's still I can see it from here it's actually getting meteor lights attached to it and they're still running and they run all night they're literally in the morning they're still running as the DA comes up and it turns off it's very good but here's the plan these are batteries usually contain protection circuitry is probably worth checking that but there I'm pretty sure the Nokia ones all do continued little protection circuit boards that is built onto the same circuit board as little gold contacts here and they have the DW or one style chip that automatically shuts off if you overcharge it and if you over discharged it so charging this you can literally so drawn to these charger connections it's marked here plus and minus and you can then charge up the current limited supply and as soon as it reaches its limit that will automatically turn off and that makes it daddy's are the sort of planner because these sort of panels if you count the number of strips in them this is one two three four five six seven eight nine 10 11 12 that's roughly half of all parrot so that equates to a total of six Vols I'm not sure if this one is rated but I'd guess it's going to be about 100 milli amp from the size of those be a bit more especially indirect something on the back it's got a t-shaped connection either end it's got that the metal strip is coming through a hole and then it's soldered and then the whole Lots all covered and resin and there's a track comes up here and then feeds these tracks so this is these are all negative connections and these are all positive connections and all you need to charge one of these batteries from a little solar panel like this which is inherently limited in the current a computer is a diode so here's what we're going to do here is the store panel which I'm not going to draw the full number of cells but let's say six volts and the positive is going to go straight across to the lithium cell and I'm going to sprayed protected it's quite important that it is protected you don't want to use an unprotected one because then it would potentially overcharge up another part in the circuit is very simple you have a diode now it would have been kind of easier just to draw as the diode in the positive side but there is a reason that I'm drawing it down here and that is because I'm going to use a dusk sense of socket and it's gonna be slightly different from the last one it's experimental it may not work and if it doesn't work you'll see it not working then we'll fix it but basically speaking we're going to use a transistor and it's one of the simplest dark sensors possible a standard NPN transistor so there's the imager going to the battery's negative rail there is the collector which is going to be switching the lords so let's put a LED up there and then a resistor to limit the current and then to the collector of the transistor and are going to use roughly a 10 ohm resistor I think might use higher depends what I'm going to do I'm hoping to drive this big string of 100 LEDs from it they're green and that's one of the most efficient colors so it should be pretty good at that and here's the very simple bit normally all you'd have to do to turn this transistor on when it gets dark is have a resistor coming down from here and then tie this to the negative side and it means that when the unit's charging this side of the diode is slightly more negative because the voltage drop across and it keeps the transistor turned off but when it's dark then the voltage across the cell reduces to the point it's not actually keeping that resistor turned off because there's no current flowing through doubt and then a resistor up here turns on but when I was doing this last time I noticed something odd I noticed that even with that resistor disconnect occurs as plymouth fires it lit and that was current flowing in Reverse through that when the sort of pun like this when it's dark you get a slight reverse leakage current through and it's enough to turn the transistor on and I got me thinking you know the easiest thing then the easiest way to do this is just to have a resistor down to the negative real and just rely when it's dark and the current flowing through here through that sort of panel through the resistor and into the transistor but it does depend on the leakage in this panel but I'm going to try this out and if it doesn't work then I'll just go to what it would have been before which would have been the resistor up here coming down there of a typical value let's say 10k I would have used up there let's try since this is kind of a let's try 10 key down here can always they experiment with it and that's the circuit that's all that's involved in this dusk Center sojourn delay it will charge the lithium cell and when it gets dark too dark to put current out from the solar panel it will then stop holding which from sister off the transistor will turn on and then it will light the LEDs until i lured Donna arises again if it it isn't drawing too much current and that sells well charged or if the cell goes too low the DW or one protection chip will cut in and I'll turn the power off until it's charged again very very simple the transistor are going to be using is a bc547c maybe not so common in other parts the world it's very common in Britain it falls into the category of elector electronics the magazine used to call a ton transistor Universal NPN they had this typical terminology top ton Doug does and it was toppers transistor universal PNP a ton transistor universal NPN doug diode universal germanium and dust diode universal silicon of what it meant was that wherever you are in the world whatever you could get just use that component that you can get because every country has its standard transistor and it's just a very simple way of doing things that means that are not specifying that components so the pin out of that one is let me see if that's the transistor with the text in the front five four seven you see it's going to be collector base and emitter if in doubt just take the name of fortunate every transistor you can get into Google and and do an image search and you'll find pictures like this while showing the pin oh it's a Google it's just a huge data sheet it's fantastic so let's start by putting the sort of panel that this battery onto the back of a sort panel I'm going to stick it on with double sided tape there's a reason for this I'm going to put two layers of tape to back up and they're going to be at both ends I'm going to just say now this is the negative this positive it's not going to work out it's going to be fail so going to overlap it to the point I can still access these sort of connections and the sort of connections on the battery they're not actually officially sort of connections let's tin them now this is a trickiest bit because they're slightly recessed but it usually takes sort of just fine this is where it probably would take sort of just over spate the middle connection is a temperature sensor I think in these most cells that will do now going to use the double-sided form pads for two reasons and I'm going to use two them it's too up off the solar panel and that's to let air flow rounder and also keep it away because the solar panel itself is going to get potentially quite hawks that's been heated by the sunlight by direct exposure to sunlight so by deliberately packing off with these foam pads that provides thermal insulation and just on a hunch I'm going to put two on to make it further apart and also leave a gap in the middle to kind of allow air flow and just ensure that any heat that does creep through is dissipated then side if this isn't an enclosure outside and I like the idea of using app a solar not a soul about a garden outdoor floodlight but actually with the solar panel inside it and just relying it as a waterproof box with the glass I quite like that idea but you could also have supposed use a bag to protect this or any clearly did enclosure all that has to do is let the Sun through I like the idea of the glass because it will filter some of the ultraviolet some of these panels the resin degrades under direct ultraviolet exposure and it results in s of frosting and heating so let's say position this try and get it fairly close to what I want and then just stick it down that's it done it's like Blue Peter but more dangerous let's also 10 those pads of the solar panel so that's the positive one it's kind of it's marked on the circuit board here so I can see it I should actually theoretically check such things I should check all artists you know you just never know if something's been marked incorrectly or assembled with the circuit board back to front let's do that so if I hold this an angle that light is going to hit it and I put the probes here I should see a positive voltage yes I do that's good and likewise just to check the battery negative and positive and are getting three point eight volts so it's about half charge the reason they say you should store lithium cells a half charge if we're going to be stirring them for a long time they recommend about three point six volts and if you workout that's between three the minimum discharges three volts and the maximum charge is four point two volts and at both the minimum and maximum the lithium is either going to be basically concentrate in one side or the other so by discharging just half our charge it to half level the lithium is defused well into this of the lithium ions are diffused well into both electrodes it just means it's at its least reactive it prolongs the life of the cells so let's say I put the charging circuit in so that's going to be from the negative to the negative connection over here I'm going to add then because it's going to make access just a little bit trickier I'm going to add the positive connection first now let me think positive is going straight to the battery connection so use that as the common for all further connections that are required and I'm going to size this to come round like this I'll leave it generous because there's no we shouldn't really need to unhide the wiring much it's going to make it easier to actually assemble this if we just leave tons of room for ourselves to work so I'll connect the positive on to the positive the battery like this train make it look relatively neat ish job done and that is going to go to the solar panels positive this is where when I try so during that later on other connections on to that it's probably gonna pop right back off but that's okay we'll deal with that when it happens and now I'm going to use the diode again I'm going to leave a few lengths just because it's more convenient so it's going to be going with the band pointing towards the negative terminal oh no it's going to be pointing yes it is actually it is going to point them towards an egg determinant using conventional current flow here we go and I'm going to fold the lead round and I'm going to put it on to the negative terminal of the battery so going to tin the end of that I could zoom down so you can see this more behave well as him down just zoom down just a little bit but not too much because otherwise it gets a bit too in-your-face so now if I flew that soda that is the charging circuit complete and there if I turn this up towards the light that battery is actually taking a charge on this sort of panel no it's not going to be a high current I'm just grab something that is super sweet right what we're going to do next let's add this one sister now the transistor is going to be and the this is going to be connected to the emitter let's bring that back in again the emitter connection which is this connection is going to be connected to the battery and where it joins onto the day or just so let's do that this could get a bit messy I'm not sure if this is how I should really have done this but I didn't think it through beforehand it wasn't planned it's a spontaneous me up as I go type of thing so let's say this is the emitter and I want to put it on to the negative terminal like that I shall solder it about ya there I'll just leave plenty of space again this can be neat and tough afterwards keep in mind that connection there which I should actually maybe cover the tape immediately afterwards is the negative terminal of coming from the back of the solar panel so now I want this terminal is gonna be the positive leading via a resistor to the LEDs so I'll just fold that up out the way this terminal is going to go with a resistor to the other side of that diode like that and this is experimental I've not tried this particular arrangement before it may not work if it doesn't work we'll fix it so I'm going to use a 10k resistor which is quite high value it means that the transistor may not turn on fully which will potentially mean that the LEDs delayed as great as they could have but I can always tweak the values so either I leave enough space that I can add I can put another resistor bridge across it for experimental purposes so gotta tin that I'm going to tin that I'm going to floor the resistor onto that and then I'm going to bring the resistor round and are going to touch it on to this side of the diode here I'm gonna lift that up just to be tired just away from the plastic insulation below of the other wire just so I don't melt it now let's try and make this relatively neat ish it's a bit late for that really isn't it it's messy but that's okay I could actually hook that underneath that seems easy enough and then floor solder on them that looks pretty good let's add the 10 ohm resistor for the LEDs which will be going between the positive connection over here and this via the resistor so what I'll do is I shall crop this lead and get my 10 ohm resistor brown black black one zero and no zeros as a multiplier and I shall tin these and stick them together like that looking pretty good this is where another sticky pad I could actually have used that to anchor it down and me actually put a double-sided pad under here and then just squish everything down onto so let's a narrow connect the LEDs that as this almost the project don't that's too easy something must have gone horribly wrong so gonna block these LEDs off here I'm gonna find the polarity and we're gonna strip this I'm sure love ultra-thin wire stripper and what I use is going to the positive terminal on the battery air and the indeed it's going down to this pad and the solar panel so I shall twist these and I shall pre-tin them and then I'll check the polarity checking the flora T is dead easy I'm just gonna hold across a lithium button cell and see which we round the LEDs laid so that's that wire tinned let's get a red sharpie n' on standby get a lithium cell dr a decent yeah this will do I'm gonna club that across it hasn't let turn it around double-check it hasn't lit either this lithium cell may be completely flat right let's try a different one there we go so I the positive side was this lead so I'm just gonna put a red dot on that and that is going to the positive connection down here that the other wire is probably going to ping right back off so going to try and hold them both down while I solder it ooh messy but that's alright I'll clean up later on he lied and then that goes over to their resistor and sorted on there and theoretically now the LEDs have lit up with the current that say because it's dark and I've liked the slightest hint of light makes the LEDs go out so it really is it's gonna have to be very dark before they come on that's quite good so let's test that let's say zoom back out and at the moment the light is charging this and I'm going to take exposure off I'm going to turn the layout and the LEDs have come on and if I get like a we torch here in shame that I had a retort record shown in that but I've misplaced that torch is this gonna work yes it is any light source at all of any modest intensity or maybe it's going to take more to to actually turn that off it's going to take a modest mode to turn that off which is kind of dude anyway and maybe not so good in another way yeah it's taking a fair amount of light I'm gonna test that with her hold on that was at its lowest setting let's see if I can do it with the this LED later it's here oh yeah no it's working that looks a lot but it's just a little cob keychain light it's not that bright swear that was really a little 8 level oh that is yeah it's happened to be really dark before that comes on but that's good because it means that it's not going to come on during delay and that is the project that has worked a treat so what's happening here there's the sort of panel here let's say it right next to that solar panel ignore the snow because it didn't end up him to use that it charges the protected lithium cell with the potential circuit muster protection circuit via this diode and while it's charging this side of the diode is effectively more negative than this just because you get the voltage drop of roughly about 0.6 volts across a diode this transistor has its emitter on this side of the diode is connected to the battery here and it's got the base that if as soon as it goes about 0.6 volts above the emitter it turns out on so the base is connected via this resistor and it's detecting the leakage through the solar panel when it's dark and when it does that when it is dark and that leakage occurs turns the transistor on which then from the charged lithium cell the current flows through the LEDs the resistor in series to the net current and then through the transistor and it will steal eight well steal it for as long as it's capacity in this battery or until the Sun should sum so there some change was back up in the morning and then it'll turn them back off but that is working pretty well I have to say that is working very well so a good result that was quite a nice simple project very easy and good result

Channel: bigclivedotcom

Views: 450,899

Keywords: solar, panel, ebay, phone, nokia, battery, reuse, DIY, LED, dusk, sensor, garden, night, light, off grid, ornament, decoration, meteor, xmas, string, fairy, dark, darkness, switch

Id: ycFTxCoNAQk

Length: 26min 58sec (1618 seconds)

Published: Sun May 06 2018