How switching power supply circuits don't interfere with others and how not to be interfered by others
Commonly used switching power supply thermoelectric part, there is a special anti-interference filtering circuit, because of obscurity, so generally do not attract attention, as for the specific location is in the fuse and varistor behind the circuit, this combination is not easy to be bad, but essential, today to talk about some of the little common sense here.
This part of the circuit is not complex, generally composed of capacitors and inductors, speaking of which, it is necessary to mention a little basic knowledge - filter circuit, a little weak electricity foundation know that capacitors and inductors can be composed of LC structure or π structure filter circuit, Lc circuit can be composed of an inductor and a capacitor, π filter circuit is composed of two The π filter circuit is composed of two capacitors and one inductor, because the structure is similar to the shape of π, so it is figuratively called a π filter circuit.
Switching power supply of this anti-interference circuit composed of inductance and capacitance features are very obvious, it generally consists of an appearance of a small transformer like inductance and two square safety capacitors, here basically will not be bad, especially the inductance is very rarely broken fault, because it is connected in series in the circuit, so the inductor does not have a short-circuit, unless the utility power is particularly stable, or safety capacitors are rarely burned out of short-circuit conditions.
The main role of this filter circuit is to filter out interference pulses from the grid to prevent interference pulses on the impact of switching power supply components, but also to prevent the switching power supply in the operation of the oscillating pulses generated by the back to the power grid, in the use of the grid of other electrical appliances causing interference.
Speaking of here we know why the capacitor here is called safety capacitor, in order to use the grid and power safety, the provisions of the switching power supply must be equipped with this filtering circuit, just like the cabinet must be equipped with the same compensation capacitor. Capacitors and inductors together to form a protective wall, not only to protect the switching power supply itself is not harmed, but also to protect not in turn does not cause interference with the power grid.
