2results about How to "Adjust duty cycle" patented technology

The invention relates to the technical field of power electronic direct-current converters, in particular to an input and output common-ground high-gain boost converter which comprises a direct-current voltage source Vin, diode components D0-D4, capacitor components C0-C4, a first coupling inductor L1, a second coupling inductor L2, a first mosfet tube S1, a second mosfet tube S2 and a resistor R. The two main loops operate in a staggered mode, so that input current is continuous, input current ripples are small, relatively stable energy is continuously provided for the circuit, the voltage multiplication unit is adopted, the amplification factor of the circuit is increased, the duty ratio of the mosfet tubes S1 and S2 is adjusted, and small current ripples can be kept even under the condition that the boost factor is large. The device has the advantages of high step-up ratio, low device stress, high efficiency, easiness in control and implementation, lower cost and the like, and is suitable for a new energy power generation scene needing high direct current bus voltage grid-connected output under a low input voltage condition.

The application provides a fan control method and system, comprising the following steps: S1, detecting the pull-up resistance of the ALERT pin and the FANFAIL pin during power-on and the clock generation circuit, and obtaining the period and duty cycle of the fan PWM signal during power-on according to the resistance value; S2, waiting for the host computer to configure the FanDCYReg register, and being in the initial state if the FanDCYReg register is not configured; S3, after the host computer configures the FanDCYReg register, the duty cycle of the fan PWM signal is determined by the FanDCYReg register, and the period is determined by the PWMFreqReg register, and the state is the normal state; S4, monitoring whether the heartbeat line of the host computer is abnormal, and if the heartbeat line is abnormal, the fan drive control mode is switched to the takeover state, otherwise, the state is the normal state; meanwhile, the pulse counting circuit directly gives the RPM speed value of the fan, and the bit width is 16, and the division operation of the host computer is not needed. The application can provide the speed RPM of the fan in real time, reduce the software resource cost of the host computer, reduce the cable between the fan and the host computer, and reduce the system cost.