Abstract: A PWM signal generating circuit and method, and an LED driver circuit using same, is disclosed. The PWM signal generating circuit generates a PWM signal for a DC-DC converter using a dimming signal, and includes an oscillator which generates a first clock signal having a predetermined frequency, a synchronizing unit which synchronizes the dimming signal to the first clock signal, and a PWM signal generating unit which generates the PWM signal in response to the first clock signal having a falling edge while the synchronized dimming signal is on.

Abstract: A pulse width modulation (PWM) signal generating circuit that generates a PWM signal for a DC-DC converter using a dimming signal is provided. The PWM signal generating circuit includes a normal PWM signal generator configured to generate a normal PWM signal based on a clock signal provided to the DC-DC converter, and a compensation PWM signal generator configured to generate a compensation PWM signal based on the clock signal and the dimming signal.

Abstract: An exhaust gas recirculation valve in a vehicle has two valves that are controlled individually by using one driving source. The exhaust gas recirculation valve enables secure operation of a vehicle even if the driving source is out of order. The exhaust gas recirculation EGR valve includes a driving unit having a driving motor for rotating a motor shaft and an interlocking unit for receiving rotational force from the motor shaft. A rod portion moves upon reception of the rotational force. A valve unit at an end portion of the rod portion controls a flow rate of the exhaust gas. A valve housing is coupled to the driving unit as one unit and has an EGR port and a bypass port. The interlocking unit includes a valve return member for rotating the motor shaft forcibly to make the valve unit to move to an initial position.

Abstract: The present invention relates to an exhaust gas recirculation (EGR) valve for a vehicle. The EGR valve includes a valve housing connected to an exhaust line for discharging exhaust gas therethrough, having a flow line with an inside area divided for taking and re-circulating a portion of the exhaust gas to a suction manifold, a driving unit on one side of the valve housing, and a valve unit mounted in a flow line of the valve housing for receiving driving force from the driving unit directly to control flows of the exhaust gas flowing through the flow line at the same time individually, thereby making stable control of the exhaust gas flowing through the EGR valve, preventing damage caused by the high temperature exhaust gas, and preventing the exhaust gas from leaking to an outside of the EGR valve.

Abstract: Disclosed is a vacuum pump for vehicles which reduces noise of exhaust air generated during operation of the vacuum pump.

Abstract: Actuator in a turbocharger of a vehicle and method for controlling the same is disclosed, in which a position of a vane is followed up in controlling a PWM signal to be applied to a motor according to time for preventing an overcurrent from flowing to the motor connected to the vane of the turbocharger.

Abstract: The present invention relates to an exhaust gas recirculation (EGR) valve for a vehicle. The EGR valve includes a valve housing connected to an exhaust line for discharging exhaust gas therethrough, having a flow line with an inside area divided for taking and re-circulating a portion of the exhaust gas to a suction manifold, a driving unit on one side of the valve housing, and a valve unit mounted in a flow line of the valve housing for receiving driving force from the driving unit directly to control flows of the exhaust gas flowing through the flow line at the same time individually, thereby making stable control of the exhaust gas flowing through the EGR valve, preventing damage caused by the high temperature exhaust gas, and preventing the exhaust gas from leaking to an outside of the EGR valve.

Abstract: An oscillator having compensation for the response delays of a Schmitt trigger has a first current source that provides a charging current to a capacitor and a second current source for providing a discharging current to the capacitor. The oscillator includes a Schmitt trigger circuit that receives a charge/discharge voltage from the capacitor and generates a square wave oscillator output signal therefrom. The oscillator further includes charge and discharge current control units that compare the charge/discharge voltage from the capacitor to respective charge and discharge threshold voltages. Based on the comparison, the control units divert the flow of charging and discharging current from the capacitor during the response delays of the Schmitt trigger circuit.

Abstract: The bias control means determines the operating mode only when the trigger input comes into a valid state or the inverted output signal is low level, and determines the power saving mode in other cases. During the power saving mode, the comparator does not operate since a bias current is not supplied, therefore, the pulse generator of the present invention can attain a low power consumption. Also, the pulse generator of the present invention can generate an output signal having a desired width regardless of the width of the trigger input.

Abstract: The present invention relates to a constant voltage control device for preventing parasitic transistors from operating, which comprises a constant voltage generating section, an undervoltage lock-out section, an operation control section, and a supply voltage control section. According to the present invention, parasitic transistors induced during the operation of a switching transistor made of a lateral transistor are prevented from operating by feedback of a signal derived from the Vref signal output from the constant voltage generating section to the operation control section. Unwanted power consumption by the parasitic transistors is reduced and malfunction resulting therefrom is prevented.

Abstract: A hysteresis system with constant threshold voltage, regardless of an increase or decrease of an output signal by detecting the increase/decrease state of the input signal, and includes a second voltage signal generator for generating a second voltage signal which is gradually increased when a first voltage signal inputted is high and is gradually reduced when the first voltage signal inputted is low, a voltage comparator for comparing the reference threshold voltage signal with the second voltage signal generated from the second voltage signal generator and producing a corresponding value; a threshold voltage initialization circuit for comparing reference voltage with the first voltage signal inputted and producing a threshold voltage initialization signal in accordance with a corresponding value; and a threshold voltage generator to which an output signal produced from the voltage comparator and the threshold voltage initialization signal produced from the threshold voltage initialization circuit are fed ba