How to make an alternating current constant
How to make an alternating current constant
For the supply of most radioelectronicdevices require a direct current. At the same time, power generators and electrical networks are suppliers of alternating current. For conversion, you need a network power supply that you can assemble yourself.
You will need
- - transformer;
- - tube or semiconductor diodes;
- - Throttle;
- - electrolytic capacitors;
- - measuring instruments;
- - accessories for soldering and installation.
Instructions
1
The network power supply consists of three mainparts: transformer, rectifier and smoothing filter. If you need a voltage approximately equal to the network voltage, then you can do without a transformer, simply by straightening the mains voltage. But such a power supply is dangerous, because its output will be the total mains voltage. In this case there is no galvanic isolation with the power grid. In addition, the transformer allows you to obtain the necessary voltage, which can be higher or lower than the network, as well as several voltages, which sometimes also is necessary.
2
Choose a transformer that gives the output voltage you need. In this case, the primary winding is designed for the voltage of your current source (generator or mains).
3
Connect to the output winding a semiconductordiode as shown in the diagram. You will get the simplest half-wave rectifier. At its output - pulsating current, the frequency of which is 2 times lower than the frequency of the mains, because you have a second half-period disappears. But to power some electronic circuits, this option is quite acceptable.
4
Significantly more advanced are thefull-wave rectifiers, in which the current ripple frequency is equal to the frequency of the mains. In this case, both half-periods of the supply voltage are rectified. If your transformer has an output winding with an intermediate point, you can assemble the device in accordance with scheme 2.
5
It may happen that you havetransformer without an intermediate point of the output winding, and the device being fed is sensitive to current pulsations. In this case, you can assemble the full-wave rectifier according to the bridge scheme.
6
At the output of any rectifier you will not receiveconstant, and pulsating voltage. It must be ironed out. For this, LC or RC filters are used. They consist of electrolytic capacitors of high capacity, between which the throttle is connected. Sometimes the throttle can be replaced by a powerful resistor. Be sure to equip your power supply with this filter.
