摘要:
An airbag apparatus connected with a battery includes activation circuits each of which has a squib and a high-side switching element, a safing switching element connected between the battery and the activation circuits, a safing switch control circuit controlling the safing switching element to provide a target voltage to the activation circuits, a terminal voltage acquiring circuit that acquires a terminal voltage of each squib, and a target voltage setting circuit that sets the target voltage. When a maximum-terminal voltage is lower than a reference voltage, the target voltage setting circuit sets the target voltage to be equal to the reference voltage. When the maximum-terminal voltage is higher than the reference voltage, the target voltage setting circuit sets the target voltage to correspond to the maximum-terminal voltage so that a reverse current is avoided in the high-side switching element.
摘要:
A drive arrangement for activating a car safety device activation element, such as an air bag, comprises a drive circuit, which is coupled to the car safety device activation element. The drive circuit generates an activation signal which activates the car safety device. The arrangement includes a power supply transistor which is coupled in series with a power supply input of the drive circuit and an energy reservoir such as a capacitor. The arrangement further comprises control means which controls the supply voltage to the drive circuit by controlling the power supply transistor to operate in an active region to provide a voltage drop during activation of the car safety device activation element. Hence, a significant voltage drop and thus energy dissipation may be moved from the drive circuit to the power supply transistor. The drive circuit may therefore be reduced in size and the power supply transistor may be implemented in a cheap technology suitable for energy dissipation.
摘要:
A switch arrangement for providing a drive signal at an output comprises a drive switch coupled to the output of the switch arrangement and a regulating element coupled in series between the drive switch and a power supply input of the switch arrangement. The drive switch is operable to provide the drive signal at the output. The switch arrangement is characterized in that the regulating element is coupled in a cascode arrangement with the drive switch such that in operation the regulating element limits the voltage drop across the drive switch to a predetermined level.
摘要:
A circuit for improving the control of a change in state of a signal in an electronic device between a first state and a second state, wherein a first change in state occurs when the state changes from the second state to the first state and a second change in state occurs when the state changes from the first state to the second state and wherein the first and second changes in state have associated therewith a first and a second time delay over which the or each change in state occurs, characterized in that said circuit comprises a determining unit for measuring the first time delay and a calculator for calculating a common delay to replace one or more of the first and second delays to thereby improve the control of the change in state of the signal
摘要:
A drive arrangement for activating a car safety device activation element, such as an air bag, comprises a drive circuit, which is coupled to the car safety device activation element. The drive circuit generates an activation signal which activates the car safety device. The arrangement includes a power supply transistor which is coupled in series with a power supply input of the drive circuit and an energy reservoir such as a capacitor. The arrangement further comprises control means which controls the supply voltage to the drive circuit by controlling the power supply transistor to operate in an active region to provide a voltage drop during activation of the car safety device activation element. Hence, a significant voltage drop and thus energy dissipation may be moved from the drive circuit to the power supply transistor. The drive circuit may therefore be reduced in size and the power supply transistor may be implemented in a cheap technology suitable for energy dissipation.
摘要:
A method of measuring a capacitor value comprises the steps of loading the capacitor up to a given voltage value; obtaining a first measure of a time for discharging the capacitor by a fixed voltage drop, the discharge of the capacitor being caused by a first current; reloading the capacitor up to the given voltage value; obtaining a second measure of a time for discharging the capacitor by the fixed voltage drop, the discharge of the capacitor being caused by the first current and by a second current of known value added to said first current; and determining the capacitor value from the difference between the first measure and the second measure, based on the given voltage drop or the given time, respectively, and based further on the known value of the given second current.
摘要:
A method of measuring a capacitor value comprises the steps of loading the capacitor up to a given voltage value; obtaining a first measure of a time for discharging the capacitor by a fixed voltage drop, the discharge of the capacitor being caused by a first current; reloading the capacitor up to the given voltage value; obtaining a second measure of a time for discharging the capacitor by the fixed voltage drop, the discharge of the capacitor being caused by the first current and by a second current of known value added to said first current; and determining the capacitor value from the difference between the first measure and the second measure, based on the given voltage drop or the given time, respectively, and based further on the known value of the given second current.
摘要:
A switch arrangement for providing a drive signal at an output comprises a drive switch coupled to the output of the switch arrangement and a regulating element coupled in series between the drive switch and a power supply input of the switch arrangement. The drive switch is operable to provide the drive signal at the output. The switch arrangement is characterised in that the regulating element is coupled in a cascode arrangement with the drive switch such that in operation the regulating element limits the voltage drop across the drive switch to a predetermined level.
摘要:
A drive arrangement for activating a car safety device activation element, such as an air bag, comprises a drive circuit, which is coupled to the car safety device activation element. The drive circuit generates an activation signal which activates the car safety device. The arrangement includes a power supply transistor which is coupled in series with a power supply input of the drive circuit and an energy reservoir such as a capacitor. The arrangement further comprises control means which controls the supply voltage to the drive circuit by controlling the power supply transistor to operate in an active region to provide a voltage drop during activation of the car safety device activation element. Hence, a significant voltage drop and thus energy dissipation may be moved from the drive circuit to the power supply transistor. The drive circuit may therefore be reduced in size and the power supply transistor may be implemented in a cheap technology suitable for energy dissipation.
摘要:
A circuit for improving the control of a change in state of a signal in an electronic device between a first state and a second state, wherein a first change in state occurs when the state changes from the second state to the first state and a second change in state occurs when the state changes from the first state to the second state and wherein the first and second changes in state have associated therewith a first and a second time delay over which each change in state occurs, characterized in that said circuit comprises a determining unit for measuring the first time delay and a calculator for calculating a common delay to replace one or more of the first and second delays to thereby improve the control of the change in state of the signal.