220V AC to 12V DC Converter Power Supply Using Diodes, Capacitors, Resistors, & Transformers

in this video we're going to talk about how to create a 12 volt dc power supply from a 220 volt ac power source so the first component that we need is called a transformer specifically a step down transformer with a turn ratio of in this example approximately 16.91 what this transformer will do is it's going to take a 220 volt ac signal or ac power source and convert it to a 13 volt ac power source this is the primary voltage on the left on the right is the secondary voltage the ratio between the primary voltage of the transformer and its secondary voltage is equal to the ratio of the primary turns to the secondary turns so the number of coils of wire on the left side is 16.9 times greater than the so with this particular transformer we can get an output of 13 volts ac or alternating current now the next component that we need is a diode a diode is a semiconductor device that allows current to flow in one direction but prevents it from flowing in the other direction so this is current flowing in reverse bias mode and in this case the diode will be off but in forward bias mode the diode is on so the diode will allow us to convert an ac power source into a dc power source it converts alternating current into dc or direct current now the circuit that you see on the screen is called a full wave bridge rectifier and before we go into that circuit let's talk a little bit more about the diode the left side of this diode is known as the anode the anode is the positive terminal and on the right side that is which is the negative terminal now when building a circuit like this looking at the diode you need to identify the part with the silver strip that is the cathode of the diode the part that lacks the silver strip is the anode