 Here Youtube, I just thought I'd show you this little find, I put it off EB and basically it's a buck converter, step down, 4 volts to 40 and you've got 0 to 37 volts out I think, 1.3 I should say, to 37 volts out, and the nice thing about this is it's got a little display here, at the moment it's showing very close to what I'm putting in, I'm putting 9 volts in, I'll show you that, 9 volts going in and it's showing about 8.9, now this bottom segment here doesn't really, let me switch the light off, and my camera's not going to do that in just this at all, with the light off it's not bad, but it does look a bit faded compared to the rest, watch your eyes, it does look a bit faded compared to the rest and the lights on especially, that actually looks like a 9 without the bottom because these two segments are a little bit dimmer than the other ones but, there you go, and so that's the input voltage, well close to it, and there's the output, now the difference between this is I've actually calibrated this, 4 volts, and I calibrated it to my meter here, and the way you do this with this is if I won't do this one again, I'll do it on the input voltage to get it to 9 volts, so I switch that to the input voltage there, 8.9 volts and if I just hold that down, and it's flashing, so I can use this little 10.10 part here, and I can calibrate the voltage down, what I'm actually doing is changing the output, ah ok that's supposed to be doing, so this is supposed to be changing the input, let me see what happens here, because this I'm pretty sure is supposed to be changing the input, that's the maximum it's going to let me have, so if I take that down to 8 volts, yeah it's ok, switching and then if I hold this in again, no I'm right, so I should hold that to 8 volts but, so that's saying 8 volts now, so if I press and hold that, and that's flashing, and this is going to change this again, I'm going to put this on 5 volts this time, yeah and that says 4.9, so I thought the whole idea was I was supposed to be able to change this for what's on there, right that turns the display on and off, yeah just pressing that button there, it doesn't turn the output on or off, which would have been nice, and this out is just for pressing so you know when where the output voltages, so at the minute that's the output voltage 4.9, this is the input voltage, if I were to hold that down it just switches off the display, so I can't adjust that there, I told them it's back on, the only way to adjust it, and it does say here, press the right key to let the display show the input or output voltage, when the right out LED lit it shows output and the left in shows the input, ok it's fair enough, but we can adjust this down to output voltage just input voltage calibration steps, step one, adjust the right button so the in LED lighted, in LED lighted, the volt meter shows the value of input voltage, press the right button for more than two seconds, one two more, press the right button for more than two seconds, release volt meter and out LED flashes, no volt meter and in LED flashes, right let's try this again because that should be flashing according to the instructions up there, so let me turn that off somehow, let's just get out the whole day in there, right let's go back, right so we're on the in and then it says to press the button on the right for more than two seconds, one two more, but this should have the input flashing that's why we think if we're adjusting the input, so we're in input calibration mode, I don't want to see that changing and we're going to set this to nine volt, I've just got to get it on it, get on it, some reason it doesn't want to play, oh there we go we're in, ok well I'm trying to turn this down and it won't go down, so I'm going to try and turn it up and although on the multimeter it goes up it's not going up on here, yeah that's just not going up and so this is the input calibration, so what I'm going to do is I'm going to see if I can turn this all the way down so we get to the limit on the pot, just to see if it makes a difference, I can't hear it clicking but I've gone around more than 10 times I know I have, so that's not actually adjusting the input, what I can do is I can turn up the input let's say to 10 volts and has this adjusted here, can I adjust it here now, ok well it's adjusted on the input anyway because it's gone to 9.9 and on my, on there to be fair to it, on there, run 9.98, yeah so that's not really allowing me to adjust that so and now we've got this set at 1.2 so if I do that for that then I'm about to say it's at 1.2, well that's a bit of crazy calibration because I'm not quite sure what really happened there, so a lot more circuits on the plane over this voltage, well they work between 4.2 and 3.7 because that's what the battery is going to be that I use to run some things, well at least that's what I've got in my head I can run quite a few things off batteries because I've got loads of these old laptop batteries, so now if I want to calibrate this I just hold this in and my multimeter says 4, this says 3.9, by rights I should be able to get these so they both say not 4, as that goes up, that goes up, ok I mean that's, so I get that pretty close to that but I don't understand how this is the calibration, 9.9 coming in which is still 0.9, before going out, turn on and off they call them the Nixie lights, I'm not quite sure if that actually worked