Experiments 1.1: Introductory Power Supply Circuit

Well, the first thing we want to do before we start is talk about the board for a second. Here is a typical dashboard. You can see that it is made up of different columns and rows, and the columns here are joined together, so, for example, in number one. We have five pins that are connected together and then we have a break in the center. We take the Gate Bridge chips through the ground and then we have another set of five pins that are also connected together, so after connecting them together. and f2j are connected to go along with this, we have two rails, two rolls and the ground rail and the +5 volt rails, what are we going to use them for, you will know if you start with some horses, there is a gap here and just break the lines of the rail, you would have two different rounds, so in our case we want to build our

circuit

so that it connects, we are going to use both sides of this rail, so the first thing we will do is simply connect a bridge over those two spaces with a couple of interconnecting wires, so press that little wire in there, okay, now we've bridged the two connections and now we want to set up our circle, so we set up our

circuit

in the corner here. so zoom in a little bit to do this now we're going to use a 9 volt battery it's just a normal 9 volt battery dc

supply

and we're going to use a jumper cap it's just a cap that lights up tonight battery volts and the term 8, about two wires and we will also use a voltage regulator to set it up.

In this case, we are using a LM 0 5 and the LM 0 5 will accept a DC

supply

and an output of around 5 volts. The chip is arranged so that it gives us our pins: this pin here on the leftmost pin is our voltage, the middle pin is our ground pin, and the rightmost pin here is our voltage, our

power

supply. 5 volts AB, so we're going to connect it to our circuit and we're just going to plug it in somewhere like this. If we plug it in this way, for example, we have problems on our board because we would be bridging the three pins. be connected and bonded so we have connected this way and it means that each of the pins we are talking about are pins 1 2 and they swap so pin 1 again is voltage towards your ground and the tree of pins is voltage So we just take our cap and connect it so the pin and the tree I'm going to connect to pin 3 now with our supply positive and fixed to our ground, we're going to connect our pin 2 to our ground representative me too.

I just want to go over a little bit because I know that pin one is going to have to be connected to plus 5 volts okay so now after we've connected to Super Ash that's our circuit configuration when I connect to the supply circuit I hope It works completely, but it's already hard enough trying to make sure the connections don't touch each other, so we can't see anything. We could measure what our voltage is that our voltage meter router supplies and measure our voltages so take your multimeter and we set it to DC voltage and if we set it to 20 volts here we should be good to measure so we should be able to measure now our input voltage, so it should be around nine volts, so we make sure we get eight point three. six volts which is what would be expected from the battery and we should be able to see our supply going down and what we get now that we have a regulated supply you should see it's about four point nine six nine seven volts so that means our voltage regulator is working perfectly now it's quite difficult to sit down because of the way our circuit is set up, what we're going to do is have a connection, a little LED to indicate when our eyes are on our circuit. is supplied, so we are just choosing a green LED and the specification for this LED is that it expects a maximum of 3 volts and an approximate current of about 232 20 million, so when our LED we see that we have two, two legs, a.

The leg is longer than the other, the longer leg is the anode and that is the positive leg and the shorter leg is the cathode and that is the negative leg. You'll also notice if you look very carefully at the plastic housing of the LED that there's a little bit of a flat area here at the top and that indicates that that's the negative or the cathode, so we want to connect this, so I disconnected the battery from this supply and I'm just going to connect it so that again the longer leg is the positive leg, so we're going to connect the - here - so I connected it to the positive rail, wow, and I connected the negative leg to pin four, so It's not connected to anything we need. to choose a suitable value for the resistor, as I said, the LED had a maximum.

I was expecting a maximum voltage of 3 volts, which means we need to drop 2 volts to our resistor to ensure the 5 volt supply is divided by that ratio, so 2 volt drop 5 volt supply means we need a resistor of 100 ohms so we connect our 100 ohm resistor and we need to plug it in from the grand Rev to our row 4 okay it's already in and just make sure it's not shorting to the positive pin of the LED okay so hold the space there and we connect to our supply and we should see when we do our LED light source, which indicates that tells us right away that our supply is connected. and that our batteries and flash and so on so we know that our circuit is working correctly, so that's our first circuit and you want to leave that configuration on the board, it's using a little bit of space on the board but it allows us the rest of the space on the board now to connect the rest of our circuit