So assuming this chip is absolutely accurate, it will actually allow the mosfet to pull current down through these resistors. which means that its open drain output turns off at 2.92 volts. that's really too high for a 2.7 volt super capacitor. Um I have just bought actually from AliExpress some 2.85 volt super capacitors, but even those really shouldn't have 2.92 volts across them.

So now I am going to attempt to solder the leg of that um voltage detector chip back on so that it's doing its job. and it was I detected that there was a problem here because I was charging the working capacitor circuit up and I got to about 2.8 volts I think and it just hadn't triggered and I thought, well, that's not right. Um, 280 should be fine, shouldn't it? Oh yuck, that tips Absolutely manky I'll just clean the iron up. Yeah! so I'm going to attempt to solder this I've got headphones on I've got glasses on I've got lights in my way I've got cameras in my way, but let's just try dabbing that back on there.

Yes, I think that's reattached and what we should see now I'll get the wires out of the way is that the circuit with the working voltage detector chip which now will be pulling the Gate of this mosfet uh, down to ground means that the discharge circuit will be switched off and the voltage on the right hand capacitor should be allowed to, um, rise up much more than the one on the left. I'm going to have to move my wire holding bits of blue tack so that we can see those voltages. and already you can see that the right hand supercapacitor is now starting to rise up in voltage with 482 milliamps of current flowing into it. I'll switch the soldering iron off to one amp now of current coming from my power supply.

I've got 12 volts coming in here from a power bank? Uh, but there's only three volts coming out because that's the total voltage across the super caps. I've written these um part numbers in here. Well, they're not part numbers, they're what's actually printed on top of the chip. The mosfet has 2n4 and in fact, in that article on Reddit people were saying oh, is this a 2N 4 Double O something Npn transistor I'm pretty sure it isn't.

it's a mosfet. Npn transistor would just get viciously hotter with. Well, it wouldn't be able to display one amp would it and also this Cnp3 voltage detector. It is the 2.2 volt version, although you you have to find it via that article on.

Reddit Okay, so with one amp, Um, I've got 1.37 on the left hand super capacitor. Uh, not enough on either of them to light these red LEDs 1.93 volts on the right hand capacitor. I'll keep charging and while I'm waiting for these capacitors to charge, press the like button. The right-hand super capacitor has now got up to 2.7 volts, which is its maximum voltage.

The left one is kind of reached an equilibrium. Actually, it may not have done yet, but it will reach an equilibrium at the current I've set which is now 800 milliamps because I didn't want to overwhelm the one amp discharge circuit here. Now the left hand LED is ever so slightly on. You can just see a dim glow there.

Of course the right hand one is not on because oh, let's just refocus on the schematic here because the right hand circuit does have this mosfet gate pulled down to ground through the voltage detector. I See So this mosfet is off. so there's no current flowing down through these resistors and there's no current flowing down through the LED and 1K resistor. That's now up to 2.8 volts.

It still hasn't triggered. This was what was concerning me because it was getting a bit. High When that gets up to 2.85 I'm going to have to kill this because um, as I say you can buy 2.85 volt capacitors, this is not one of them. This is a 2.7 volt capacitor now.

I don't I Just if this chip is working as we, uh, according to the datasheet accurately, In fact, I've limited this at 4.5 volts so it can't go any higher now. Um, it ain't going to trigger till 2.92 volts. So no, this is not working terribly well at all. And I think that I'm going to have to change the potential divider ratio for this to trigger at a lower voltage on the rise where the hysteresis does come into play in order that this protection circuit actually works at 2.7 volts so not 2.92 And now of course I Can't get this capacitor to discharge because as I say it's protection circuit won't operate so dirty gray.

H4 Car Headlamp bulb. Let's put that across the capacitor. bring it down to 2.7 volts because it's oh, it is A. There was a faint glow there, but it's the only way I can get that capacitor down to its rated operating maximum voltage which is 2.7 volts like so.