Receiving a direct current from variable is carried out by means of the process called straightening. For this purpose use rectifiers of various designs. The way of turning on of the rectifier depends on its type.
Instruction
1. To use the special lamp called the kenotron for straightening of alternating current use together with him the transformer having a filament winding with the operating voltage of 5 V for 5Ts3S and 5Ts4S devices, or 6.3 V for devices 6Ts5S and 6Ts4P. This winding has to be well isolated from the others, including, from filament. Also it has to be calculated on current of heat of a lamp. From it it is impossible to feed any other loadings. The secondary winding with which tension needs to be straightened has to have branch from the middle. Connect extreme conclusions of this winding to kenotron anodes. Remove a positive pole of the straightened tension from the lamp cathode, and negative - from branch.
2. To carry out one-half-period straightening by the semiconductor diode, include it between a source of alternating voltage and loading so that the cathode of the diode was turned to the loading entrance on which there has to be positive tension. There is no mistake here: the diode will open when positive tension is present at its anode, connecting thereby to the power supply the cathode to which loading is attached.
3. For implementation of two-half-period straightening by two diodes connect their cathodes together. The device similar on a configuration to the kenotron will turn out, but not demanding heat. It also has two anodes and one general cathode. Further include it as well as the kenotron, using the transformer with the secondary winding having branch from the middle. It is clear, that the filament winding in this case is not necessary.
4. If the secondary winding of the transformer of branch has no, turn on four diodes according to the special scheme called a pavement or use the ready vypryamitelny bridge. Connect a secondary winding to the bridge entrances designated by the sign of alternating voltage, and remove the straightened stress from exits, designated as plus and minus.
5. In all cases, correctly choose vypryamitelny devices in such parameters as the maximum return tension and the maximum direct current. If necessary, install them on heat sinks. Remember that in some cases heat sinks should be used separate, not connected with each other.
6. Any rectifier develops the pulsing tension, suitable unless, for power supply of collector engines. That pulsations stopped, connect parallel to the output of the rectifier the electrolytic condenser of the filter in the correct polarity. Pick up its capacity experimentally that pulsations decreased to acceptable value. Tension on which the condenser is calculated has to exceed considerably straightened idling.
7. Remember that some rectifiers develop tension, life-threatening and are powered such tension. Also you remember that condensers are capable not only to filter the straightened tension, but also to remain long loaded.