You will need
- In order to lower the voltage, you'll need the damping resistor, the damping reactive impedances, thyristor regulators.
In order to obtain a significant voltage drop, you need to add a lot of resistance. Try to use this damping resistor. This device can be purchased at specialty stores, but you can collect yourself. But it must be remembered that the use of such a damping resistor, it is meaningless, a large amount of power.
If you need to lower voltage in AC systems, try to use jet quenching impedances. In conjunction with the usual condenser get the real capacitor in the power supply.
Voltage circuit without transformer can be lowered by means of a thyristor regulators. Assemble your own at home them pointless, so better to buy ready-made at a specialty store. Their electronic circuit due to the fact that on the half cycle AC you can control the delay of the thyristor, can significantly change the power supplied to the load.
If you need to reduce the voltage supply in the circuits with variable and constant current, in this case, proceed as follows. In series connect the Zener, microbore stabilizer or instead you can connect a switching Converter. The second device should be performed based on the necessary degree of lowering of the supply voltage. All of the above electronic devices work the same way as semiconductors. From this it follows that to use them better if you have a certain range of knowledge in the field of electronics.