How does a mobile charger work?

We use our smartphones on a daily basis.

But, have you ever ever puzzled however your smartphone charger works? You would understand that charger converts AC to DC, however it is not that easy. First, It converts AC to DC save for back to AC, then finally to DC. Today we tend to ar attending to see however the charger will this, and why ar there intermediate steps. This is a standard charger that converts 220 volts AC to five volts DC. Let's see what is within. Now we will see all the electronic parts employed in it. There ar diodes, capacitors, transistors, and resistors, additionally there ar resistors below the PCB. This is a electrical device, associate degreed this is often an optocoupler. Once power is provided it activates. To understand it higher let's set up the circuit. Now we will see all the parts and connections. This red wire is section wire and also the black is neutral. First, we've may be a resistance. By perceptive the colour bands and reference table we will see its 260-kilo ohms (2.6 ohms). This is a liquified resistance that forestalls harm from overloading. Then there's a bridge rectifier created by four of 1 n4007 diode and a filter condenser of 450 volts and a couple of.2 microfarads. This circuit converts AC to DC.

This is associate degree generator circuit this converts DC back to high-frequency ac of fifteen to fifty kilocycle. We can see the values of the parts. This is junction transistor s8050, this is often its pin configuration. And this is often junction transistor 13001, this is often its pin configuration. This is a diode, it's sort of a Zener diode however it is a quick switch diode 1n4148 and a condenser of fifty volts twenty two microfarads. this is often AC to DC convertor for the phototransistor in optocoupler, It forms a circuit like this. This is the electrical device, it's 3 windings primary, secondary, and auxiliary winding wrapped round the core. it's accustomed step down the voltage. The auxiliary winding is employed to run the generator circuit. Then we've a Schottky diode 1n5819 with a condenser of ten volts 470 microfarads to convert AC to DC and a light-emitting diode for indication. Also, there's a electric circuit that consists of associate degree optocoupler pc817c and four.2 V Zener diode. This is associate degree optocoupler. It is used for the transmission of the signal while not contact. On the proper facet, we've may be an infrared light-emitting diode and on the left is a phototransistor. When the light-emitting diode activates its light-weight activates the bottom of the phototransistor turning it on. This condenser is of 102 nano capacitance unit used for safety functions. It is connected between primary and secondary grounds to prevent magnetic force interference. Let's flip it on and see in action. The inexperienced wires carry the positive voltage and the blue wires carry the negative voltage or ground. Also, we will see the voltage within the circuit on the graphs. We have the input of 220 volts 50(60) hertz AC. This is a bridge rectifier, it converts AC to unsteady DC. As we will see this unsteady DC filters from the condenser and becomes nearly pure DC. We can see we've as DC within the circuit. Now, this current passes from the two megaohm resistance to the bottom of T1 turning it on. This junction transistor is not absolutely turned on, owing to the resistance it activates part. Due to partial turning on of the junction transistor an occasional current passed from the first winding of the electrical device, this induces an occasional voltage within the auxiliary winding. The evoked voltage currently charges the condenser then the condenser absolutely activates the junction transistor. As the junction transistor is currently absolutely on that permits this to flow through itself. Now, this activates the junction transistor T2, that shunts the bottom of the T1 turning it off. As the T1 turns off the flow of current to the T2 is bring to an end. Now this flows to the bottom of the T1 and also the cycle repeats. This happens at fifteen to fifty kilocycle that may be a thousand-fold quicker than the rectifier circuit. Hence, you'd see that the rectifier circuit is stopped. At an equivalent time, the voltage from the auxiliary additionally turns the diode on and charges the condenser, and flows to the optocoupler. This diode and condenser convert the AC from the auxiliary coil to DC for the optocoupler. The current is additionally evoked within the coil. This is reborn to DC by a Schottky diode and a filter condenser. It is indicated by the light-emitting diode. however what if the voltage is over five volts. Hence, we've a electric circuit.

As we tend to reach four.2 volts the Zener diode activates permitting current to flow to the optocoupler. It additionally drops the voltage by four.2 volts thence the light-emitting diode of the optocoupler does not activate. The light-emitting diode needs zero.8 volts to show on. When the voltage reaches over five volts this activates the light-emitting diode of the optocoupler. The light of the light-emitting diode activates the phototransistor of the optocoupler permitting this to flow to the junction transistor T2. This activates the junction transistor T2 shunting the primary and stopping the flow of current within the coil. Also, the voltage within the secondary facet of the electrical device drops below five volts, turning off the Zener diode and optocoupler, and also the circuit continues to run commonly. Now you'd have the question why indirectly convert AC to DC then this? This is owing to the traditional power offer that is at 50(60) hertz. The size of the electrical device and also the capacitors ar giant. They cannot be mounted in an exceedingly tiny charger like this. Hence within the charger, the fifty(60) hertz frequency is reborn to 50 kilocycle. This reduces the scale of the electrical device and condenser needed within the circuit. So to vary the frequency of AC 1st we've to convert it to DC then once more back to AC. Now you recognize however the charger that we tend to use daily works.