The structure and related advantages of the thyristor rectifier of the charger
28 Mar 2022
Silicon controlled rectifier is a power control appliance based on thyristor (power electronic power device) and with intelligent digital control circuit as the core. It has many advantages such as high efficiency, no mechanical noise and wear, fast response speed, small size and light weight.
The characteristics of the silicon controlled rectifier: it is "triggered". However, if a reverse voltage is applied to the anode or gate, the thyristor cannot conduct. The function of the control pole is to turn on the thyristor by applying a positive trigger pulse, but it cannot turn it off. So, what method can be used to turn off the conducting thyristor? Turning off the conducting thyristor can disconnect the anode power supply or make the anode current less than the minimum value to maintain conduction (called holding current). If an AC voltage or a pulsating DC voltage is applied between the anode and cathode of the thyristor, the thyristor will turn off by itself when the voltage crosses zero.
Thyristor (Thyristor) is the abbreviation of thyristor, also known as silicon controlled rectifier, formerly referred to as thyristor. Because the voltage and current capacity it can withstand is still the highest among power electronic devices at present, and its work is reliable, it still has a relatively important position in large-capacity applications.
At present, our chargers use unidirectional thyristors, which are commonly referred to as ordinary thyristors. It is composed of four layers of semiconductor materials, with three PN junctions and three external electrodes: the electrodes drawn from the first layer of P-type semiconductors. It is called anode A, the electrode drawn from the third layer of P-type semiconductor is called control electrode G, and the electrode drawn from the fourth layer of N-type semiconductor is called cathode K. As can be seen from the circuit symbol of the thyristor, it is a unidirectional conductive device like a diode. The key is to add a control electrode G. The electrode drawn from the third layer of P-type semiconductor is called the control electrode G, which makes it have completely different operating characteristics than diodes.
