Toggle switches are used in almost all electronic circuits. Semiconductor diodes are used in many circuits. It is an early-born semiconductor device and its applications are also very wide. The pn junction formed by the n-type semiconductor and the n-type semiconductor forms a space charge layer on both sides of the interface, and a self-built electric field is built. When there is no applied voltage, the diffusion current caused by the difference in the carrier concentration on both sides of the p-n junction and the drift current caused by the self-built electric field are equal and in an electrical equilibrium state.
Diodes are used in the switching circuit of the diode in the toggle switch. Since the switching speed of ordinary diodes is not high enough, the diode used in this switching circuit is a special switching diode. It can be seen that while the switching diode is equivalent to a switch Sl at this time, there are still two resistors.
The switch Sl in the equivalent circuit can be regarded as an ideal switch, that is, its on-resistance is as small as zero, and its off-resistance is as large as infinity.
Small micro switches according to the way the switching devices are connected in the circuit, the switching power supplies currently widely used can be roughly divided into three categories: series switching power supplies, parallel switching power supplies, and transformer switching power supplies.
Among them, the transformer-type switching power supply of the small micro switch (hereinafter referred to as the transformer switching power supply) can be further divided into: push-pull, half-bridge, full-bridge, etc.; according to the excitation of the transformer and the phase of the output voltage, Divided into: Forward, Flyback, Single and Double, etc.
Small micro switch-if it is divided by purpose, it can also be divided into more types of series switching power supplies. The disadvantage is that the input and output share the same ground. Therefore, it is easy to produce EMI interference and the bottom plate is charged. When the input voltage is the mains rectified output voltage It is easy to cause electric shock when it is not safe.