eg: 12V 1A EU adapter

          electronics components ac adaptor

          Publicly listed Stock Code: 891359

          invention patents inside

            Main Content
          The Essence Of Self-excitation Circuit
          Add time:2010-12-05    Click:653

          The essence of self-excitation circuit is actually a single-tube self-excited oscillation circuit, adding pulse width control circuit and voltage regulator became the basic sampling circuit switching power supply, of course, but also add the necessary practical circuit over-current protection.

          Self-oscillating circuit in addition to the adjustment means to adjust the pulse width, there is a way - modulation, frequency modulation circuit
          More complex, have become obsolete, the basic need. I've seen the model seems to have: Telefunken ***, are some European brands.

          Self-oscillating circuit has two basic components: a resistor (about 20-47 ohms) and a capacitor in series,
          They will switch the transformer is a winding of the pulse signal fed to the transistor base, in order to maintain a stable oscillation state transistors