Slow-starting circuit, power panel provided with slow-starting circuit, and service single board provided with slow-starting circuit

Abstract

The invention provides a slow-starting circuit, a power panel provided with the slow-starting circuit, and a service single board provided with the slow-starting circuit. The slow-starting circuit comprises a slow-starting MOS tube, a slow-starting driving control triode and a power supply circuit. The power supply circuit supplies power to the slow-starting driving control triode so as to determine the delay duration of the triode from the turn-off to the turn-on of the triode. From the power-on moment of a power input end, the power supply circuit supplies power to the triode and the triodeis turned on after the above delay duration. When the triode is turned on, the slow-starting MOS tube is turned on. From the power-off moment of the power input end, the power supply circuit stops supplying power to the triode. The triode is therefore turned off and then the slow-starting MOS tube is turned off. According to the invention, the discharge speed of the grid of the slow-starting MOS tube is accelerated. Meanwhile, the risk caused by the fact that a traditional slow-starting circuit is frequently turned on and off can be solved.

Description

technical field [0001] The invention relates to the technical field of communication equipment power supply, in particular to a slow start circuit, a power board and a service board including the circuit. Background technique [0002] In the case where the slow start circuit is set on the service board of the communication device, the communication device requires the replacement or restart of the service board without powering off the whole machine, which requires the power supply circuit of the device port to support hot swapping Function; when the slow start circuit is set on the power board of the communication equipment, the power supply circuit of the power board is also required to support the hot swap function. [0003] Now commonly used slow start circuit see figure 1 , the input power supply part is easily connected to the socket unstable when it is just inserted into the socket or when the socket is replaced, resulting in rapid power-on after power-off at the inp...

AI Technical Summary

Problems solved by technology

[0003] Now commonly used slow start circuit see figure 1 , the input power supply part is easily connected to the socket unstable when it is just inserted into the socket or when the socket is replaced, resulting in rapid power-on after power-off at the input end. In this case, the large filter capacitor C2 at the output end discharges slowly, which will cause Charge C1 all the time, although the original intention of the triode VT1 is to discharge the power on C1 as soon as possible, because C1 is slowly discharged through the diode VD2, VT1 is not turned on at all, so C1 cannot discharge quickly, resulting in the slow start of the drive of the MOS transistor VT2 The voltage cannot quickly drop to 0 volts, so that in the case of fast startup again, the slow-start MOS tube cannot function as a slow-start, and is always in the on state or half-on state. The consequence of this is that if the slow-start MOS tube VT2 happens to be on When the input terminal is powered on again in the half-open state, the slow start MOS tube will generate a large inrush current and instantaneous stress, and there is a risk of damage

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