Communication Power Introduction power supply
The switching power supply system used in communication base stations has higher and higher requirements for safety, efficiency, and quality. Whether it is a newly built communication base station or an existing communication base station, in order to ensure the normal operation of the communication switching power supply system and avoid damage to communication equipment, it is necessary Focus on ensuring the performance safety of the switching power supply.
There are mainly two types of power supply on the market: linear power supply and switching power supply. The working principle of the linear power supply is to convert the 220V mains power into a low-voltage power such as 12V through a transformer, and it is still a low-voltage alternating current after the transformation; and then through the electronic circuit diode After rectification and rectification, the low-voltage AC alternating current is converted into a pulsating voltage.
The communication switching power supply uses modern power electronic technology to control the time ratio of the on and off of the switch tube, and realizes the rectification and conversion of the AC 220V to DC 48V, so as to ensure that the high-frequency switching power supply maintains a stable output voltage, and the high-frequency The switching power supply is controlled by pulse width modulation (PWM), and is mainly an electronic circuit composed of IC and MOSFET;
The power supply uses a PWM circuit to realize the rectification of the circuit voltage. When the input voltage of the power supply will be corrected into a square wave again before passing through the switch tube, the AC rectification will be directly converted into DC through the input terminal of the internal circuit, and then it will be oscillated at high frequency. Under the action of the circuit, the switching tube is used to control the on-off of the current, thereby forming a high-frequency pulse current; and then with the assistance of an inductor or a high-frequency transformer, the high-frequency switching power supply is guaranteed to output a stable low-voltage direct current. The loop that feeds the PWM control circuit inside the power supply is responsible for the adjustment function. If the output voltage of the power supply is wrong, the PWM control circuit of the power supply will change the control signal of the duty cycle to adapt to the transformer, and finally correct the output voltage of the power supply.
Through the introduction of the power supply above, it can be known that the PWM control circuit of the power supply controls the closing or opening of the power switch tube according to the output load of the power supply. If the output voltage of the power supply is too high or too low, the PWM control circuit inside the voltage will change the voltage. The waveform is adapted to the switching tube, so as to ensure that the power supply has the purpose of correcting the output voltage.
