Husnen Rupani:
Hi, I’m Hus. I’m the CEO of Infinispark. I have more than 12 years of experience in the electrotechnology training industry, so I understand the concerns of compliance, learner attrition, and increasing demands on trainer’s time. Welcome to DC Pracbox video. In this video, I will show you how the DC Pracbox can assist in staying compliant, how it can increase your practical training hours by 300%, and how it can cut the trainer’s prep time substantially. Towards the end of the video, I will show you a comparison between series and parallel circuits with lamps on the DC Pracbox, so please stay tuned for that.

The DC Pracbox is designed for the DC circuit units of certificate 2 and 3 of electrotechnology. All the components in this equipment are chosen from the range statement or range of conditions of relevant units of competency. Let’s take an example of D44. The DC Pracbox covers 100% of the practical activities required in the performance criteria and the performance evidence of this unit. So you can rest assured that any practical exercise or assessment conducted with this equipment will lead you towards compliance, and this takes out the guesswork completely. Traditionally, a unit like E104 has only had eight hours of prac out of 80 nominal hours. This is not enough practical training and leads to risk of non-compliance and high learner attrition. When we conducted the training using DC Pracboxes, we were able to increase the prac time to 32 hours, which is 300% higher than the traditional approach. This not only engage learners more in training, but also improve compliance. We also offer 30 practical exercises, including marking guides, as an add-on to enhance your student’s learning experience. To explain this point, I want to go over the components we have in the DC Pracbox.

Here, we have six power resistors that are 25 and 50-watt. That way, they can handle a lot of current. So you’ll be able to use it for series and parallel circuits without worrying about damaging them. Here, we have a transformer where you can use it for measurement of resistance of wires, or you can do insulation test across the primary and the secondary side. In this column here, we have a 12-volt LED that’s directional, then we have a fuse holder where you can put different types of fuses and see how they work in different circuits.

Here, we have some fixed resistors, color-coded resistors that have different wattage ranges, and this part is variable resistors. These two are temperature-dependent resistors, or thermistors. This one is a voltage-dependent resistor, or a Barista. This is a light-dependent register, or LDR. And this is a potentiometer, or a pot. These four are incandescent lamps that are 12 volts and 3 watts. Compared to LEDs, LEDs are directional, and these ones are not directional, but the difference is these ones will draw more current, and that’s the reason why we’ve put them both here.

These three are electrolytic capacitors that are not polarized. Usually, electrolytic capacitors are polarized, but they then pose a risk or hazard of damage, where if you were to swap the wiring, then you can blow the whole equipment up. But this one is non-polarized, so you’re safe from that hazard. These four lines here are nichrome wires with different lengths and thicknesses. So you can then measure the resistance of those wires and compare them to the resistances of copper from this side in the transformer. This switch is a SPDT toggle switch, which is similar to the switch make that you use in your normal light switches. So you can see that in a different form factor.

On this side of the box, we have a multimeter where the multimeter is powered from the inside of the box, which means you don’t need any batteries, so that’s one problem solved. The fuses inside the meter have been pulled out and put on the panel. So you don’t have to pull apart the meter every time the fuse blows. All you have to do is uncap these fuse holders and replace it with a new fuse. Here, we have an analog voltmeter. So you get practice of measuring voltage through analog and digital meters. And this is the power supply controller. It’s very powerful. It can give you very minute changes in voltage and current, both.

There are more than 30 components in this equipment. If you had to manage a class set of 10 of these without the DC Pracbox, you would be looking after 300 components in total, which would be a nightmare. Normally, maintenance of a multimeter can take up to 20 minutes per meter. If you had 10 meters, that’s 200 minutes or over 3 hours. With our built-in multimeter, this reduces to 30 seconds per meter. The DC Pracbox doesn’t just save substantial amount of time, but also provides learning flexibility because all you need is a DC Pracbox, power cable, and banana leads, and you can do the prac anywhere there is power available. Now, let’s see the DC Pracbox in action.

I’ll show you a demo of how you can show ohm’s law with the DC Pracbox. So we’ll use the power supply here that’s right now set to 10 volts, but it’s turned off. So I’m going to connect that from the supply to 5-ohm resistor here. Now, we’ll score direct connection. Usually, you would put a switch in there. But just to explain it to you, how simple it could be to demonstrate it, I’ll just use direct connection. So, if I turn that on, you see how we’ve got 10 volts and the current of 1.97. Now, if you look at exact calculations, it’ll be 10 divided by 5. So you’ll have 2 amps, but we’ve got 1.97.

Now, if I move the resistance, if I change the resistance value, the current will change. Let’s see that in action. So I’m going from 5 ohms to 10 ohms, and you can see how increasing the resistance has now decreased the current from 2 amps to close to 1 amp. If I go even further, if I go from 10 ohms to 20 ohms, the current will have even further. And now, instead of 1 amp, I’ve got half an amp. So that’s how easy it is to demonstrate part of the ohm’s law.

As promised, I will show you the series and parallel comparison using these lamps. So let’s start with one lamp first. So, right now, my supply is set to 12 volts, but it’s turned off. So I will start with the first lamp.

So one lamp connected. If I turn that on, I can see that lamp is turned on and I’ve got a current of 0.24, or 240 milliamps. If I connect these lamps in parallel, let’s do a parallel connection, parallel connection is basically each terminal is piggybacked on the other. You can see how the two lamps have the same brightness and the current has now doubled. Let’s keep going. Same brightness again. But with four lamps, the current has now increased by four times, but the voltage is still the same. Let’s measure the voltage across one of these lamps and see what we get. So, to measure the voltage, I will use our multimeter here in volted settings, so connecting that and that. And as you can see, the voltage is 11.9 or 12 volts. If I was to move that measurement to, let’s say, this last lamp here, I’m still getting 12 volts, right? So that means that every single one of these lamps is getting the same voltage. Now, this is parallel connection.

Let me change this to series connection and see what happens. So, now, we’ll connect these lamps in series. So we’ll start with the first lamp and we’ll finish the circuit on the last lamp. So let’s turn the power on. Now, at this stage, the circuit isn’t complete because one wire is on this side and the other wire of the power supplies on this side, so we don’t have a complete circuit. Let’s continue connecting it. Now, even though this lamp is connected on both sides, it’s not a complete circuit because the current doesn’t have any more paths. So we’ll keep going.

And now, you can see there is a very dim light in each one of these lamps. So, when we had these in parallel, all of them had the same brightness, and they were quite bright. But now, they’re all in series and they’re fairly dip. Let’s measure the voltage across them. Last time, when we measured the voltage, it was showing 12 volts. Let’s see what it says now. So, now, it’s showing 2.8, rather than 12 volts. If I measure the voltage across other lamps, 2.9, let’s see the last one, and 3. So, they’re roughly 3 volts each. That’s the difference between series and parallel connection.

In this demo, I’ll show you the charging and discharging of this capacitor. So let’s connect the charging side of the circuit.

So this is the discharge side of this circuit. Let’s connect the analog voltmeter across the capacitor to see how it’s charging and discharging.

Okay. So, right now, the voltage shows zero volts, which means that there is no charge stored in this capacitor. Let’s turn this on. Right now, we’re on the charge side. So let’s turn this on and see how this needle is increasing. That’s showing that the capacitor is charging.

Okay. Now, to discharge, all I have to do is flip this switch on the opposite side, which will then put this capacitor that’s charged across that LED, which means that LED will turn on and the capacitor will start to discharge. So let’s see that in action. LED is on, the voltage is dropping. As the voltage reaches close to zero, and almost zero there, the LED is almost out.

Gary Wattie:
For the time factor, it’s massive. Yeah. Well, literally, don’t have to look at anything, like the globes there, all the box, that they basically just grab it and do it. Yeah, it’s massive time-saving. Huge. Fantastic.

Husnen Rupani:
We offer ongoing phone and email support, so you will always feel support. Our aim at Infinispark is to work with you to maintain compliance, increase learner engagement, and give the trainers back some time. Please get in touch with us to see how we can work together.

Thanks for watching.