Hello, this is a DC electronic load. It's the A Torch Dl24m and I think the M I Hope the M Uh stands for modular because this is indeed modular. This is the main unit here in the middle and then you can add these additional fan modules which increase the power capability when it's doing its electronic load duties. So Center module is 150 watts, 25 amps, add another module, you get another 150 watts, but you only get an additional 5 amps.

So two modules is 30 amps, 300 watts, three modules which is what I went for I Bought these two additional modules. Uh, it's 450 Watts 35 amps Now that 35 amps has to go through this connector. It also goes through this diode because there's a sort of anti-reverse polarity protection diode there and you can imagine 35 amps going through that. It's going to get quite hot.

It's got this little heatsink and when these fans come on, it is kind of fan cool, but it's kind of secondary. It's not independently cooled. Okay, let's take a quick look at the underneath and you can see there the mosfets. There are four per board, so there are 12 here in total and they are Irfp 264s.

Now on the top of the board, you've also got these resistors. They are R25s, so they're a quarter of an OHM Uh, six. Watts Now I Don't think they're there specifically to burn off heat. they're obviously part of the circuit.

Um, of these mosfets. Let's have a look at the date sheet for these mosfets because they're quite interesting. So here it is Irfp264 and you can see it's a high voltage mosfet um 250 volts, but it has quite a high on Resistance here 75 milliohms. And of course, in this application you want a high on Resistance because you want to burn off energy as heat.

This has to be independently powered through this. DC Barrel Jack So I'm using a a 12 volt USB type-c to power Um trigger unit and then a USB type-c power bank and it uses very little current so that power bank is not going to drain out in any, uh, short order. Now, the little screen unit you can probably see is not terribly bright and it's on this sort of uh cable which plugs in at the front here. So I've tucked it underneath.

um, and it's There are no real mounting things on it other than these thin strips of sticky. So I've just stuck it on here with, um, some blue tack because that seems a sensible place to put it. But let's have a little closer look at that display. So here it is.

I've dropped the blinds to make it look a little brighter. Um, you've got voltage, current, power, effective resistance, total energy, and total milliamp hours here. Also, you've got various modes. This is in constant resistance mode, so it will impose a five or it will make itself appear to be a 5 ohm resistance and dissipate whatever energy a 5 ohm resistance would dissipate.

So let's go through the various modes. so press and hold M and then it flashes the mode and then you can go up or down. So that's constant power. but you get very little time so I'll have to whip through them really quickly.

Constant power. That's battery resistance test Power supply test Cable test Constant current and constant voltage and constant voltage. I'm having a lot of trouble with. Let me just check if there are any more modes.

no back to constant resistance. You can also limit the time that this thing is on for if that's useful to you. And you can also set a cutoff voltage so that if you're testing batteries, you can say stop the process or stop pulling power or current. Um, when the voltage gets down to whatever voltage you set there and there are various temperature sensors, there's in temperature I'm not quite sure what that is actually.

there's board temperature and that's the one that goes up when this thing starts burning energy and you can set a point where it will trigger the fans. I've set it to 40 degrees. We'll watch the fans come on in a moment. There's also external temperature down here because there is a supplied external temperature sensor.

Um, Accessories that come with this are this little adapter board which has the various USBS type, C, Micro B, Mini B and also a DC Barrel Jack If you want to test power supplies, there's a little um American to Euro adapter thing screws which are the screws that you have to put through the holes in the Pcbs to bolt the modules together. You get lots of those and you get two 10 amp leads with these Forks which fit into this front terminal block and you get the external temperature sensor so I can get that one out. Just go back to the screen a moment. Um in the off mode if you press and hold the on off button which is the one at the bottom, there you go into the background settings.

Um, this is M moves you through the fields and plus or minus changes the data in those fields. So one of the first things I did I set the standby brightness to maximum brightness. Um so that when it dims after 99 seconds, it doesn't actually dim because dim is unusable. Um, you've got oh well.

You can see what you've got here. all sorts of things including the over voltage cut off 210 volts that's set to overpower cutoff is kind of the total power of the unit because I've got three modules so that's the 450 watts and again with the over current 35 amps you can have over external temperature cut off, over board temperature cut off I Suppose that would only be used if the fans fail because the fans are automatic and keep the board temperature constant. I've got my fan control temperature to come on at 40 degrees. it automatically goes off again 10 degrees below that and then you can zero out the data and that's what I wanted to do.

actually I wanted to zero out the data. So let's M down to the zero the data uh, data zero and then I think you press OK it says okay and then long press to get out of that menu right Time to do an actual discharge. So positive goes into that left one. Hook that up to the positive of my battery.

I'm using this Um 4 S2p Lithium-ion phosphate battery pack, right? That's positive and negative. Hooked up to my battery. So let's zoom in on the screen and start a discharge. I'm going to do this discharge at 3 amps constant current.

You can see the voltage of the battery as it's just hooked up with the unit not doing anything 13.1 volts. So we'll press the on off button that switches it on and the unit will pull three amps from the battery because the voltage will dip. There's the three amps it's pulling. Uh, it's 38.

Watts You can see the effective resistance and it's counting up the Watt hours and the milliamp hours. I Suppose what I'm more interested in is watching the temperature rise. Well, perhaps I need to raise the amps. So now the M button which is here moves the cursor on the top line there.

So that's three amps Now the plus button can take me to 4 amps and again to 5 amps. I'm pulling 5 amps now. That should make the Um transistors, the mosfets on the bottom of the boards warmer, and I've got my fan temp trigger set to 40 degrees. So when this gets to 40 degrees, we'll see the fans come on.

So all that power 63 watts is being dissipated. Um, well, almost all in those uh mosfets on the bottom of the boards. So I can feel that these heat sinks are now starting to get pretty warm. The board's temperature is up to nearly 39 degrees now.

so I'll just leave the camera running and we'll watch that go up to 40 degrees and then you'll see all the fans come on. So 39.67 8, 39.9 40 degrees The fans come on and they will stay on until the temperature Falls all the way back to 30 degrees because there's a 10 degree hysteresis built into this electronic DC load and I'll just catch the point where the fans go off. at 30 degrees, it's down to 31 degrees there. So yeah, I've been playing with this in constant current mode, constant resistance mode, constant power mode.

The only one that's behaved very strangely is constant voltage mode. but I don't think there. go the fans I don't think there's any point trying to cover that in this video because I'm going to keep this quite short. But if you're interested in seeing the problems this unit has when operating in constant voltage mode, then I'm quite happy to make another video about it in due course.

Now there is also an app. um, the screen unit there has Bluetooth in it. You can see it's very, very basic. Uh, really.

all it does is mirror some of the parameters, mirror some of the buttons so we can switch on and off. the um, well, switch on and off the unit. it's still on. In fact, if I switch it off, I'll do it remotely with the enter button I Think it is.

We should see these graphs fall so the voltage doesn't change much, but the current and power parameters fall to zero. Of course, switch it back on and those go back up. Now this does store the data in one second increments and you can export that as an XLS file, but that's pretty much all this does. It's really very basic and I think this app works with several different products that a torch make, so that's a little.

Look a first look at the a torch dl24 MP I think it is uh, electronic DC load with consonant current, constant resistance, constant power, and also this quirky constant voltage mode like I Say, let me know in the comments below if you'd like to see this attempting to do constant voltage because I can tell you an ad doesn't do a very good job, That's it for this video. Cheerio.