Abstract: In a first microcomputer, a communication function is provided for outputting a data signal having a transmission period Tr that has a relation of Td<Tp/2 with a data time Td, and it sends various data processed by itself and carried on the data signal to a second microcomputer, where the received data signal is sequentially stored in a memory, and the various data are read by timing pulses for reading and processed.

Abstract: A mechanical acceleration switch acting in response to a collision involving a vehicle tends to occur with chattering, thereby lowering the reliability of operation due to insufficient application of an ignition current to an igniter of an air bag in the vehicle. When the mechanical acceleration switch is closed and first-stage igniters are ignited, a forced igniter is turned on. Even if chattering occurs in the mechanical acceleration switch, the first-stage igniters and a backup capacitor are conductively connected by turning on a driving transistor, such that an electric current is sufficiently delivered to the igniters. As a result, it is possible to improve the reliability of the operation of starting the air bag. Furthermore, it is no longer necessary to increase a capacity of the capacitor and change the constitution of the mechanical acceleration switch to decrease chattering therewith.

Abstract: A mechanical acceleration switch 12 acting at the time of collision tends to occur chattering easily, thereby lowering reliability in operation due to insufficient application of ignition current to an igniter of an airbag. When the mechanical acceleration switch 12 is closed and first-stage igniters 4 and 7 are ignited, a forced igniter 115 is turned on. Even if chattering occurs in the mechanical acceleration switch 12, the first-stage igniters 4 and 7 and a backup capacitor 11 are completely conducted by turning on a driving transistor 31, and an electric current is sufficiently delivered to the igniters 4 and 7. As a result, it is possible to improve reliability in operation. It is no longer necessary to increase capacity of the capacitor 11 and decrease chattering of the mechanical acceleration switch 12.

Abstract: An alternating current discharge lamp lighting apparatus including discharge lamp, tube wall temperature measuring unit, internal temperature inferring unit and period setting unit. The tube wall temperature measuring unit measures temperature of the tube wall of the discharge lamp. The internal temperature inferring unit infers internal temperature of the discharge lamp before discharge is started based on the tube wall temperature measured by the tube wall temperature measuring unit. The period setting unit sets a direct current voltage applying period based on the inferred internal temperature by the internal temperature inferring unit.

Abstract: An inverter circuit produces a proper electric power to be supplied to a discharge lamp. A feedback control system detects a lamp voltage and a lamp current, or a lamp power of the discharge lamp, and feedback-controls the inverter circuit based on the detected at least one of the lamp voltage, lamp current and lamp power. A response switching circuit switches a response speed of the feedback control system so that the response speed is high in a low luminous efficiency region, and is low in a high luminous efficiency region.

Abstract: A discharging lamp lighting apparatus is provided with predicting means for predicting final discharging lamp voltage of a discharging lamp, and discharging lamp control means including a discharging lamp voltage-discharging lamp current corresponding characteristic to instruct current applied to the discharging lamp by discharging lamp voltage fed to the discharging lamp, for performing lighting control by using a value predicted by the predicting means. It is thereby possible to feed the optimal power to the discharging lamp according to a variation in the final discharging lamp voltage due to quality or an operating time, and reduce a time required for stability of luminous flux.

Abstract: An apparatus for lighting a discharge lamp is provided with an inverter circuit 3 for causing an input power supply 2 to generate the voltage required for a discharge lamp 1, a rectifying smoothing circuit 4 for rectifying and smoothing the output of the invertor circuit 3, a feedback control circuit 8 for computing the power required for the discharge lamp 1 so as to control the feedback control circuit 8 in the feedback mode, a polarity switching circuit 9 for switching the polarity of the rectified and smoothed output to apply the output to the discharge lamp 1 with a low-frequency square wave, and an ignitor 11 for superposing a high-voltage pulse on the discharge lamp 1 when the discharge lamp 1 is started.