Friday, 12 July 2013

HOW TO MAKE A BRIDGE RECTIFIER

Hi friends today i will tell you how to make a bridge rectifier.
Here is the list of essential components required:-
:Four IN4001 diodes,
:5cm by 4 cm copper clad board(CCB),
:FeCl3 (20 grams),
:Permanent marker
:Connecting wires (insulated),
:Shouldering iron and Shoulder with flux paste,
:One 470 uf,50 volt electrolytic capacitor,
:Multimeter for Voltage testing.
First we go through the schematic diagram of bridge rectifier  as shown :-

As we can see that the diodes are connected together in a particular pattern.There are four junctions formed after connecting the diodes in which two junctions are obtained by joining like poles or terminals of the diodes while others are obtained by joining dissimilar  poles or terminals.
There are two terminals of a diode one is p-type and other is n-type. A diode is that device which allows current to flow in only one direction and blocks current in other direction.
A diode is represented as shown:
The arrowhead pointing towards a line is the cathode means it is n-type material and the tail of arrowhead is the anode i.e. p-type material .But in practical purposes a diode is in the shape of a grain seed so to identify the cathode terminal a black line is marked adjacent to the cathode terminal as shown.







Now to make PCB of the bridge rectifier we have to make the following design on the copper clad board (upper side of CCB) using a permanent marker diligently.Do not over draw the copper clad board surface.Make the holes as shown using hand drill with 1mm bit.Now to make the proper connections the excess copper i.e. unmarked copper has to be removed.


To remove excess copper a high corrosive substance FeCl3 is used.The ferric chloride solution can easily dissolve the excess copper on the PCB. So to do this the PCB is dipped into ferric chloride solution obtained by dissolving 15 grams of ferric chloride to 200ml of water.
The PCB is dipped with proper care as ferric chloride is highly corrosive substance and can harm our body skin.It is dipped for 15 minutes.
After 15 minutes we can now see that the excess copper is removed and our PCB is partially ready.With the help of water wash the PCB and with thinner remove the marker ink.
Insert the proper terminals of components in their respective holes and shoulder each terminal with copper clad board using shouldering iron and flux paste.
Here is the Bridge Rectifier:-











Note:-
Always connect negative terminal to the cathode of electrolytic capacitor otherwise it will bust. 
You can also transfer the circuit design to the PCB by using laser printer.Just print this design on a magazine paper using laser printer and put the printed  surface of paper in contact to the copper clad board and put the cloth iron on it so as to give heat.Consequently,the design is transferred to the copper clad board and the rest of the process is same as explained above.