Simple controller of the fan speed
This article is mainly for beginners who have difficulty in making the rotation controller of the fan. This article provides two simple circuits to adjust fan speed. Both are based on the integrated stabilizers KR142 series and very easy to manufacture.
The first scheme uses KR142EN12A stabilizer is adjustable voltage from 1.5 to 45 volts.
Because of the low boundary voltage stabilization circuit schemes added trimmer which set the minimum fan speed, and guaranteed him a reliable start.
The second scheme was completely repeats the scheme of rotation controller of the company ZALMAN.
Both schemes have been tested and have shown good results. The simplicity and reliability of these schemes can recommend them to repeat the newcomers. In some cases it is useful to establish a small chip on the radiator. And, you can thus control the brightness of the LED backlight control.
Instead KR142EN5A you can use А7805Т, KIA7805, L7805CV, LM7805 and other.