Good morning, all today, i want to get this evse electric vehicle supply equipment to think that it's connected to a car when it actually isn't so for this experiment, i'm going to remove the type 2 cable and plug entirely and connect other stuff into the terminal block Inside the evse, so let's take the evse apart again, i'm not sure how many times this device is going to want to be taken apart before it starts to fall apart, but i guess we'll find out now. I should say that in this video i'm going to be messing around with mains voltages, which can be extremely dangerous, so please don't copy what i'm doing. I mean i'm 60 years old. I've had a good innings.

So if i make a terrible mistake, uh it's my fault, isn't it, but if you're, young and beautiful, then i would definitely steer clear of doing things like this. So fair warning given and i'm going to actually make this as safe as i can i'll explain in a moment. So the idea here is that i'm going to connect this, which is a light, bulb holder onto the live and neutral outputs of this unit. And that's so that i can see when this device turns its relays on and when it's supplying mains to the car, which will just be a little terminal block in this instance um.

And i'm also going to try and simulate. What's inside the car. To a certain extent, as far as i can to see what this device does and whether it thinks it is connected to a car, so let's put my lamp holder through the gland or grommet and attach it to the live and neutral blocks on here and then I'll find a bulb that i can put in there now, the other two connections that i want access to and i'm going to use one of these wires, which i made up um some time ago, actually for the lighting in my shed 12 volts. Well, these two connections have only 12 volts on them, so let's put them in there now, which do i use for control pilot and which do i use for protective earth.

The original wiring had black going to control pilot but red on protective earth, yeah not so sure about that right. So that's my wiring i've put red on control, pilot cp and black on protective earth. So i'm just going to put the back on this thing. So i can flip it over and we can see the display and then we'll try and work out a way of making this think it's connected to a car, now control pilot and protective earth.

I'm going to connect to this terminal block so that i can connect additional things to that. So, let's put protective earth up there and control pilot down here so for additional safety, i'm going to supply mains to the evse from this power bank. It's only capable of 200 watts output. Now that can still kill you if you put one hand on live and the other hand on neutral that will pass across your chest, so it can still be dangerous, but it's safer.

I reckon than putting in full strength mains from a household socket, so let's connect that up and see this thing come on, so the evse has come on now. Control pilot and protective earth should be um galvanically isolated inside this unit. From main, so i should be able to touch those, and i can that's absolutely fine, so this should be safe to work on to try and pretend we've got a car connected to this evse now. Currently, the lamp is not on.

I don't know which way this switch goes, but certainly mains is not being put through to the lamp, so the relays in the evse are off and that's because it's saying plug this thing into a car, i can't see a vehicle, so we now have to try And put something on here such that this thinks it's connected to a vehicle and i've printed out this from the wikipedia article on j 1772 and come on ignoring proximity pilot for the moment. Because we know that the wire inside the evse connected to the proximity pilot pin doesn't go anywhere, it's been cut off, so we can ignore all the stuff on the pp pin, but the control pilot. This pin 4 goes into a diode and down through a 2.74 k resistor to ground, which is protective earth. So if we put a diode and a resistor 2.7 k, i haven't got a 2.74 across those two connections.

Then will the evse see this as a car? There is also the option here to switch in a 1.3 k resistor via this relay, but we'll come back to that later. Right, diode and 2.7 k resistor, and i'm going to be really lazy here and just twist. These together, which i know, is really enough, but i just can't be bothered to get the soldering iron out so, let's twist those together and then i'll connect these to my terminal block and we'll see what happens. Let's actually do this sort of live, as it were put my finger on there, switching between standby and connecting and the lights.

If i take that off, the lights are blue in standby. If i connect that and of course, i'm putting a different resistance on this with my fingers, but it does say connecting i'm not sure whether it's actually turned the mains on yet i don't think it has no not yet now it's just wondering whether this device would Time out, i've got my diode and resistor on there permanently. Will this time out if it doesn't see whatever it needs to see to go into charging mode, but it doesn't seem to be timing out. It seems quite happy to wait there and i think the next stage of this is to close this relay as it were and put this is it 1.3 or 1.2? I think it's 1.3 k there not sure if i've got a 1.3 k resistor and put that also across yes, it's switched to ground, isn't it so also across this resistor, thus pulling this voltage down even further.

You see this voltage. 12 volt is sourced here, 12. Volts but it goes to a 1k resistor, so by pulling it down through this diode, with a 2.74 k resistor, we pull the 12 volts at this point down to about nine volts, and that indicates that the car is connected, so it says connecting then the car Should respond by closing this switch with an additional resistance, further pulling this voltage down from 9 volts to 6 volts, and that's probably, what will trigger the evse to switch on the mains and then this bulb should come on. Well, i don't have a 1.3 k, but i do have a 1.2 k.

So let's put that across this resistor and see what happens and yes, it's gone into charging now my lamp hasn't come on. That's probably because of that switch. Let's try again there. It is the mains is being sent right through this unit and to the car, or in this case that bulb because it can see now that the control pilot signal, the top half of it and that's the function of this diode.

It's only pulls the top half of the one kilohertz square wave down to six volts and that puts it in charging mode. If i take that away, oh it says end: okay, now, let's try a couple of things. I'll turn off the mains which i can do on my power bank. Now what happens if the mains comes onto the evse with the connector plugged into the car, so it should be seeing this diode and 2.7 k resistor.

Let's turn on the mains. The evs e comes on in standby, but then fairly quickly goes into this connecting mode, so it doesn't seem to matter. If we have this pull down to nine volts. Remember it's only pulling down the top of the waveform to nine volts.

The minus 12 part at the bottom of the waveform and i'll get a scope in a minute remains at -12 volts, and i think the idea of that is so that if i don't know your um type, 2 plug was lying in a pool of water, and There just happened to be 2.7 k between protective earth and control pilot - it's unlikely, but it could happen seeing this asymmetry by virtue of this diode means that it's not going to turn the mains on when the connector is lying in a puddle. So now i've connected both resistors in parallel, so that we're pulling the top half of the square wave down to six volts and it's turned the mains on. Let's turn off the supply to the evse, so that drops out and see if it's happy to see this situation immediately, it powers on put the power on the evse, standby and yeah. It goes straight into supplying power, so the relays have closed and it's supplying mains power to the car.

So it doesn't seem to mind there doesn't seem to be any kind of sequencing required if the conditions are satisfied. It just gets on and supplies power to the car. Now one thing i wanted to test: if i short out this diode with a crocodile clip cable, then we're going to pull down both the top half of the square wave and the bottom half. Will it detect that there is then symmetry on the pull down? No it doesn't.

It doesn't seem to care whether the diet, i'm not sure whether this um crocodile clip's any good. Actually, perhaps i'll, try another one. Well, let's try this again in the connecting state. So my second resistor is disconnected: let's see what happens if the diode is not there and no, it doesn't seem to care about that.

So it doesn't seem to be uh, taking much notice of whether or not that diode's in circuit i'll just get another crop clip, because i can't be sure this is a good one right. I've got a new uh crocodile clip lead. This one's got an s on it, which means i've soldered the wire to the crocodile clip, because the crimped ones can be quite bad and the little c there means that it's high current i've got a decent piece of wire on there um. So why isn't it going into? Oh, it's gone into end mode.

Oh that's interesting! Yes, but if i put the second resistor across there, it immediately goes into charging mode. It's saying end, rather than connecting, which is slightly odd, um. Okay, let's make it conduct and now short out this diode. No, it doesn't seem to care whether or not the pull down on the square wave is symmetric or asymmetric.

I think it's time to get a scope and have a look at the uh square wave on here. So here's my scope hooked up now, i'm having to use this additional light here, otherwise it bleaches out the screen of the scope. It's just an exposure compensation thing. I suppose i could do that on the camera, but never mind i've done this now, so we can see that it's exactly one kilohertz.

The width of the pulse is about ten percent, which is what you want for six amps. You can see six amps there and if i press the current button in this end state i can actually vary the current, so 8 amps is more than 10 um, that's 10 amps 13 amps and this one goes up to 16 amps. I can't remember the percentages. Just at the moment, let me check right: i've done the exposure compensation on the camera.

Now, oh, it's not quite as good. Is it uh? How do i adjust that? No, that's not working terribly well. It's also put a thing up on my screen, so i can't see very well but never mind so yeah. So you can see i can press the current control button and that just varies the pulse width of this uh waveform.

So let's go back to six amps. That's a ten percent pulse width. Now, if i close this second resistor, which turns on the relays, the other thing you can see is that the height of the positive part of the waveform drops to 50 percent from 75 percent, so 9 volts down to 6 volts. But the bottom part of the waveform is unaffected and that's because of the diode.

So let's now see what the effect of putting my shorting link across the diode is i'll. Hang that resistor over there permanently to turn on the mains, let's short out the diode um. Yes, the scope should be right with that, shouldn't it and yes, you can see there that the bottom part of the waveform is also reduced in amplitude, as well as the top, but that doesn't seem to be noticed by the evse. Oh, why is the screen gone? All funny like that, i don't know.

Yes, i think when this was intermittently contacting and we were glitching the mains on and off, like that, i think it interfered with the signal going to the display and that went funny, but it seems okay now so yes um. It's simply a case of a diode and two resistors uh one to pull the signal down to nine volts and another one to pull it down to six volts that initiates the charging turns on the relays and actually supplies mains well, in my case, to the bulb. But there doesn't seem to be any sequencing required. You just simply put the resistors in and even if both resistors are in when you power up the evse, let's just try that power it down power it up, then very quickly.

It just goes straight into charging mode. So no sequencing required. It seems now something else i wanted to try, which is. Can i change the current while it's in the connecting mode we've seen that i can change it while it's in the end mode, whatever that means so that's 16 amps.

Let's turn off the mains turn it back on and see whether i can because it'll go straight into connecting mode, because it's got the diode and resistor see. If i can change the current now - and i can so now - let's put it in the charging mode with the second resistor, my mains lamp comes on and now pressing the button. I can't change the current so as it stands, this evse wouldn't be able to have the current modulated by, for example, the amount of solar power coming off my roof, while it's charging, because it simply doesn't respond to changes in requested current or maximum current. While it's in the charging mode, you'd have to come out of the charging mode, which would be not a very nice thing to do, change the current and then go back into the charging mode, which is not ideal really and, as we've seen, this particular evse doesn't Seem to care if you short out the diode and just have the resistor and then put a second resistor on there.

It doesn't seem to care whether this signal is uh pulled down symmetrically or asymmetrically. It connects the mains, regardless, not sure, that's ideal, really so there we are all you need to make an evse think that it's connected to a car is a diode and a resistor and then another resistor to tell it or for it to think that the car Is actually charging it's as simple as that? Cheerio.