How to make a rectifier ?
rectifier electric current is called a special device which is intended to produce an output direct current from the AC input.Most rectifiers accept filters to smooth unidirectional pulsating voltages and currents generated by them.
Why do I need a rectifier
main disadvantage of electrochemical cells supplying many electric appliances, is a small battery life.These disadvantages are particularly evident if the required load currents of great strength.For power electronic consumer best electric current industrial power.But connecting device provided for feeding the battery directly to the network is impossible.You must convert the alternating voltage network constant.Therefore, it is useful to understand how to make the rectifier.To supply equipment commonly used voltage less than the supply voltage.This is achieved by using a power transformer.Then convert AC to DC.Constant obtained in two stages:
first variable image is converted into a pulsating, ie, varying from zero only in one direction.The filter converts the pulsing voltage constant.
- Half-wave - rectifier, consisting of a capacitor and a semiconductor diode.Its design is very simple.Very low efficiency, so only used to power a low power consumers.
- -wave - rectifier consists of a transformer winding, capacitor and four diodes.Usually it is performed in a bridge circuit.It is used to power radio.
Diodes selected by parameters: value for DC (rectified) current at the rectifier output and the value of the reverse voltage.These parameters are taken from handbooks.The rectified current can not be less than the current that the load consumes.Diodes are heated if the rectified current will be 2 times greater than the desired current consumer.Reverse voltage consists of a voltage of the secondary winding and the voltage across the capacitor.
- Take a half-liter glass jar or glass plate area 40h100 mm - aluminum and copper, rubber tube with a diameter of 2 cm We cut 2 cm from the tube and put on an aluminum plate..This is because during operation the electrolyte is strongly corrodes aluminum.If he put on rubber, it protects the metal from corrosion, and the rectifier will last much longer.
- As the electrolyte will use baking soda solution.It will need 5.7 grams per 100 ml of water.For the positive pole accept aluminum, as well as the negative - lead.The current goes, if you connect the rectifier lead plate in the network.But the current will go in one direction only.The aluminum plate is a constant positive voltage pole.
- If the network include aluminum plate, the plate will be the lead negative pole.This will be a half-wave rectifier, through which the current flows only one half.In this case, the positive direction of the current will flow.
- full-wave rectifier is used to use the power completely.The number of elements from which they are made dependent on the required value of the rectified current.Connect them to the two-phase mains.
- Use fuse when you turn the device into a network.With the rheostat voltage can be adjusted.
- define the alternating voltage of the transformer secondary winding:
U2 = B Un,
Un - continuous load voltage, V;In
- coefficient, which depends on the load current.
- determines the maximum current flowing through the diodes:
Id = 0.5 Ir,
Id - current flowing through the diode,
Ir - the highest current value,
C - a coefficient depending on the load.
- define reverse voltage:
Uobr = 1.5 Un,
Uobr - reverse voltage,
Un - load voltage.
- choose a diode in which the value of rectified current and reverse voltage higher than estimated.
- Let us find the value of capacitance:
Sf Ir = 3200 / Un KP,
Sf - capacity filter capacitor,
Ir - the maximum load current .;
Un - load voltage,
KP - ripple (10 -5 -10-2).
Welding rectifier VD is used as a power source for welding any electrode.It is used to eliminate interruptions mezhtokovyh welding, whereby the weld quality is obtained.
- rectifier versatile, can be used in the most demanding conditions.
- Insensitive to temperature fluctuations, humidity changes, the voltage drop in the network of dust.
- has low cost and can replace expensive installation.
Now you know all about who wants to know how to make a rectifier at home.This will allow you to solve the problems on its own absence and with the least expenditure of funds.