In Russia an overwhelming part of electric devices works from the alternating current main of 220 volts. But in certain cases there is a need for increase or decrease in this tension.
Instruction
1. If you have to lower tension twice – for example, for food the lowered glow lamp tension, turn on the powerful diode in a chain. It will cut off one half wave, as a result tension will be 110 V. The fact that it will be constant for the glow lamp does not matter. Such way of inclusion is useful where low energy consumption and long service life of a lamp is required.
2. For increase in tension use autotransformers. Their design allows to set voltage level at the exit, raising it within 50 volts. Autotransformers are usually used in networks with the lowered tension – for example, in rural areas where voltage drop is rather habitual phenomenon. By means of the autotransformer it is possible and to lower tension in the same limits. But consider that at big decrease or increase in tension the autotransformers are strongly heated. Using them, always consider the power of loading on which they are designed.
3. Voltage stabilizers allow to support voltage of 220 volts. Most often they are used at the lowered tension, they are capable to increase it by several dozen volts. At turning on of the stabilizer do not exceed the power of loading on which it is designed.
4. It is possible to increase tension by means of the multiplier – the special device consisting of diodes and condensers. Similar multipliers are used in power-supply circuits of anodes of kinescopes, increasing tension approximately to 25-27 thousand volts. In more detail about multipliers you can read here: http://radioskot.ru/publ/spravochnik/umnozhitel_naprjazhenija/2-1-0-363.
5. If necessary to raise or lower tension you can reel up the self-made transformer. Exact formulas of its calculations are rather difficult therefore use an approximate formula: n = 50/S where n is number of the rounds of a winding falling on 1 volt of tension. S – area of a magnetic conductor. When using Highway-shaped plates the area is equal the work of width of an average uvula of a plate on package thickness, in centimeters.
6. Example of calculation: if width of an average uvula of 4 cm, package thickness – 5 cm, then S=20. Having divided 50 into 20, you receive 2.5 rounds on 1 volt. Then primary winding will have 220 x 2.5 = 550 rounds. If in a secondary winding you have to receive, for example, 300 volts, then it requires 750 rounds (350 x 2.5). This way of calculation is most applicable for the low-power transformers intended for power supply of the radio-electronic equipment and other devices of low power.