Abstract: A large format printer performs serial printing on a medium which is greater than or equal to A3 short side width. The large format printer includes a print head which performs printing in accordance with variations in a drive voltage signal which is applied to a drive element, a control circuit which generates a drive signal (an example of the drive voltage signal), and a cable which is greater than or equal to 1 m and transmits a power voltage signal (an example of a constant voltage signal) and the drive voltage for driving the print head from the control circuit to the print head. An overshooting prevention circuit which renders a voltage (a drive voltage) of the drive signal which is applied to the drive element less than or equal to a voltage (a power voltage) of the power voltage signal is disposed in the print head.

Abstract: A large format printer performs serial printing on a medium which is greater than or equal to A3 short side width. The large format printer includes a print head which performs printing in accordance with variations in a drive voltage signal which is applied to a drive element, a control circuit which generates a drive signal (an example of the drive voltage signal), and a cable which is greater than or equal to 1 m and transmits a power voltage signal (an example of a constant voltage signal) and the drive voltage for driving the print head from the control circuit to the print head. An overshooting prevention circuit which renders a voltage (a drive voltage) of the drive signal which is applied to the drive element less than or equal to a voltage (a power voltage) of the power voltage signal is disposed in the print head.

Abstract: The present invention provides a power-supply device, which can continuously supply a voltage from a power supply to a load even if a breakdown of a circuit is generated. The power-supply device includes a booster circuit, a normally-closed bypass relay, a CPU, and a switching circuit. A first switch of the switching circuit is turned on by a switching signal from the CPU, and a second switch is turned on by a boosting request signal from a boosting request signal generator. In the case that one of or both the switching signal and the boosting request signal are not input to the switching circuit 14, because a coil of a bypass relay is not energized, a contact turns on, and a voltage is supplied from a DC power supply to the load through the contact.

Abstract: An electric leakage detection apparatus may quickly detect an electric leakage. An electric leakage detection apparatus includes a pulse generator that supplies a pulse to a coupling capacitor, a voltage detector that detects a voltage at the coupling capacitor, an electric leakage determination unit that compares the voltage detected by the voltage detector to a first threshold and determines presence or absence of the electric leakage of a DC power supply based on a comparison result. The electric leakage detection apparatus also includes a discharge determination unit that compares the voltage detected by the voltage detector to a second threshold lower than the first threshold and determines whether the detection voltage becomes lower than the second threshold by a discharge of the coupling capacitor. The pulse generator generates a new pulse when the discharge determination unit determines that the detection voltage becomes lower than the second threshold.

Abstract: The present invention provides a power-supply device, which can continuously supply a voltage from a power supply to a load even if a breakdown of a circuit is generated. The power-supply device includes a booster circuit, a normally-closed bypass relay, a CPU, and a switching circuit. A first switch of the switching circuit is turned on by a switching signal from the CPU, and a second switch is turned on by a boosting request signal from a boosting request signal generator. In the case that one of or both the switching signal and the boosting request signal are not input to the switching circuit 14, because a coil of a bypass relay is not energized, a contact turns on, and a voltage is supplied from a DC power supply to the load through the contact.

Abstract: A power-supply device has a DC power supply, a load, a booster circuit disposed between the DC power supply and the load, wherein the booster circuit supplies a voltage at the DC power supply to the load while boosting the voltage, a bypass element disposed between the DC power supply and the load, wherein the bypass element constitutes a bypass path with respect to the booster circuit, a controller that controls an operation of the booster circuit, a first switching element that drives the bypass element in a first driving path, and a second switching element that drives the bypass element in a second driving path.

Abstract: An electric leakage sensing apparatus includes a pulse generator that supplies a pulse to a coupling capacitor, a voltage detector that detects a voltage at the coupling capacitor, an electric leakage determination unit that compares the voltage detected by the voltage detector to a threshold and determines existence or non-existence of an electric leakage of a DC power supply based on a comparison result, a pre-check circuit that puts the DC power supply into a pseudo electric leakage state, a diagnostic unit that diagnoses whether the electric leakage determination unit determines that the electric leakage exists when the DC power supply is put into the pseudo electric leakage state, and terminals to which cables are connected. A current route from the pulse generator to the pre-check circuit through the coupling capacitor and the cables is formed when the DC power supply is put into the pseudo electric leakage state.

Abstract: An electric leakage detection apparatus may quickly detect an electric leakage. An electric leakage detection apparatus may include a pulse generator that supplies a pulse to a coupling capacitor, a voltage detector that detects a voltage at the coupling capacitor, an electric leakage determination unit that compares the voltage detected by the voltage detector with a threshold, and determines presence or absence of the electric leakage of a DC power supply based on a comparison result. The electric leakage detection apparatus may also include a discharge circuit that is operated for a constant time after the pulse falls and forcedly discharges a charge of the coupling capacitor. The pulse generator generates a new pulse when the constant time elapses.

Abstract: An electric leakage detection apparatus may quickly detect an electric leakage. An electric leakage detection apparatus includes a pulse generator that supplies a pulse to a coupling capacitor, a voltage detector that detects a voltage at the coupling capacitor, an electric leakage determination unit that compares the voltage detected by the voltage detector to a first threshold and determines presence or absence of the electric leakage of a DC power supply based on a comparison result. The electric leakage detection apparatus also includes a discharge determination unit that compares the voltage detected by the voltage detector to a second threshold lower than the first threshold and determines whether the detection voltage becomes lower than the second threshold by a discharge of the coupling capacitor. The pulse generator generates a new pulse when the discharge determination unit determines that the detection voltage becomes lower than the second threshold.