48results about How to "Change duty cycle" patented technology

The invention discloses a method for controlling an anti-lock system of a four-hub-motor drive electric car free of hydraulic braking, and relates to the field of automotive electronic control. In each control stage, braking force distribution of a front axle and a rear axle of a vehicle and reverse braking, regenerative braking, reverse-regenerative coordinating braking and forward driving of an in-wheel-motor are related. A logic threshold control method is adopted in ABS control, the slip rate (S) is compared with a set threshold value, the value and the direction of input voltage of the motor are controlled so that the forward driving, the reverse braking and the regenerative braking of the motor can be achieved, and accordingly wheel lock is prevented. The slip rate of a wheel is controlled near a theoretical value, the ground attachment coefficient is utilized to the maximum extent, and safe braking is achieved.

A developing device includes a developing roller, a magnetic roller, a capacitor, a transformer, a switching section, a control section, a temperature detecting section, and a storage section. When changing the duty ratio of a control signal in multiple sequential steps, the control section determines the resonance period based on the temperature and temperature characteristic data and changes the duty ratio of the control signal to the next step during a changing time slot which is one of the first and second halves of a period of voltage fluctuation of the capacitor based on the determined resonance period, the one half in which the current flowing through the switching section is smaller than in the other half of the period.

The invention discloses a microfluidic sampling system, which includes a quantitative sampling module, an air pressure drive and control module, and a negative pressure generator; the quantitative sampling module includes a sample pool, an inlet working channel, a first one-way valve, a first hydrophobic Valve, quantitative sampling chamber, second steam trap, third steam trap, second one-way valve, inlet working channel; the first one-way valve is set on the inlet working channel; the second one-way valve is set on the outlet working channel The inlet and outlet ports of the quantitative sampling chamber are respectively the first steam trap and the second steam trap; a third steam trap is arranged between the second steam trap and the second one-way valve; the pneumatic drive and control module includes a micro air pump, The miniature solenoid valve and the controller, the air pump is the air source to provide the driving pressure, the solenoid valve and the controller form the control unit to control the on-off of the driving pressure. The system can improve the precision of quantitative sample injection, and can control the flow rate and flow rate of the sample according to the principle of pulse modulation during sample injection, and can save the cost of sample injection.