The power supply system for communication base stations has higher and higher performance requirements such as safety, efficiency, and quality, especially in the construction of new base stations and the replacement of old communication equipment in existing base stations. In order to ensure the normal operation of the communication power supply system and avoid damage caused by wiring errors For communication equipment, in this case, it needs to be considered that the communication equipment itself has an anti-reverse connection protection device, so as to realize the anti-reverse connection protection function of the communication equipment. According to the actual situation, there are the following protection measures against reverse connection:
1. Using diodes to prevent reverse connection of power supply
Utilizing the characteristic of unidirectional conduction of a diode, in an electronic circuit, when a suitable forward voltage is applied to both ends of a diode, the corresponding diode is turned on; and when a reverse voltage is applied to both ends of the diode, the corresponding diode is turned off. According to this characteristic of the diode, the anti-reverse circuit of the power supply can be realized, and the diode can be connected in series in the forward direction; when the power supply is reversed, the electronic circuit will not conduct, and the load will not work so that the load will not be burned.
2. Use P-MOS to prevent reverse power connection scheme
According to the fact that the MOS transistor is a voltage-controlled semiconductor device, it can be divided into two types: P-MOS and N-MOS, both of which have three electrodes, namely gate G, drain D and source S. The P-MOS device can be used to realize the anti-reverse connection circuit of the power supply.
3. Use N-MOS to prevent reverse power connection scheme
According to the working principle of the N-MOS anti-power reverse connection circuit is the same as that of the P-MOS, but the difference is that the N-MOS needs to be connected to the negative side of the power supply, that is, the low end. When the N-MOS power supply circuit is reversely connected, the gate G is low level, VGS=0, so the N-MOS is not turned on and the electronic circuit does not work.
4. Use the rectifier bridge to realize the non-polarity scheme of power supply wiring
The rectifier bridge is used to realize the non-polarity of the power supply, so that the forward connection and reverse connection of the power supply can be realized to ensure the normal operation of the circuit. The corresponding circuit rectifier bridge is an electronic circuit composed of four diodes. It is especially suitable for the rectification circuit from AC to DC. In each cycle of the AC circuit, two diodes are turned on at the same time, and the other two diodes are turned off at the same time. The non-polarity anti-reverse connection function is realized through such sequential rotation.
By introducing the above power supply anti-reverse connection scheme, it can be applied to power electronic circuits, so as to ensure the normal operation of the power supply and reduce the power supply burnout caused by reverse connection.