Monitoring device for at least one ignition circuit for a personal protection means for a vehicle, and method for operating a monitoring device

A method for operating a monitoring device for at least one ignition circuit for a personal protection device for a vehicle, the at least one ignition circuit designed to activate the personal protection device when at least one of:

• i) an ignition voltage is present that exceeds a voltage threshold value, and ii) an ignition current is present that exceeds a current threshold value, the monitoring device including a control device, and a voltage source connected via a voltage source terminal of the control device, the control device being connected via a high-side ignition circuit terminal to a first supply terminal of the ignition circuit and via a low-side ignition circuit terminal to a second supply terminal of the ignition circuit, wherein the monitoring device designed such that a no-load voltage of a high-side current source of the control device situated between the voltage source terminal and the high-side ignition circuit terminal corresponds at least to the voltage threshold value, the no-load voltage corresponding at least to a maximum ignition voltage of the ignition circuit, the method comprising:
• connecting the high-side ignition circuit terminal to the high-side current source, a and connecting the low-side ignition circuit terminal to a voltage sink terminal;
• activating the high-side current source;
• determining a difference voltage signal between the high-side ignition circuit terminal and the low-side ignition circuit terminal;
• and
• ascertaining an ignition circuit resistance using the difference voltage signal.

A control device for operating a monitoring device for at least one ignition circuit for a personal protection device for a vehicle, the at least one ignition circuit designed to activate the personal protection device when at least one of:

• i) an ignition voltage is present that exceeds a voltage threshold value, and ii) an ignition current is present that exceeds a current threshold value, the monitoring device including a control device, and a voltage source connected via a voltage source terminal of the control device, the control device being connected via a high-side ignition circuit terminal to a first supply terminal of the ignition circuit and via a low-side ignition circuit terminal to a second supply terminal of the ignition circuit, wherein the monitoring device designed such that a no-load voltage of a high-side current source of the control device situated between the voltage source terminal and the high-side ignition circuit terminal corresponds at least to the voltage threshold value, the no-load voltage corresponding at least to a maximum ignition voltage of the ignition circuit, the control device configured to:
• connect the high-side ignition circuit terminal to the high-side current source, a and connect the low-side ignition circuit terminal to a voltage sink terminal;
• activate the high-side current source;
• determine a difference voltage signal between the high-side ignition circuit terminal and the low-side ignition circuit terminal;
• and
• ascertain an ignition circuit resistance using the difference voltage signal.

A non-transitory computer readable storage medium on which is stored a computer program for operating a monitoring device for at least one ignition circuit for a personal protection device for a vehicle, the at least one ignition circuit designed to activate the personal protection device when at least one of:

• i) an ignition voltage is present that exceeds a voltage threshold value, and ii) an ignition current is present that exceeds a current threshold value, the monitoring device including a control device, and a voltage source connected via a voltage source terminal of the control device, the control device being connected via a high-side ignition circuit terminal to a first supply terminal of the ignition circuit and via a low-side ignition circuit terminal to a second supply terminal of the ignition circuit, wherein the monitoring device designed such that a no-load voltage of a high-side current source of the control device situated between the voltage source terminal and the high-side ignition circuit terminal corresponds at least to the voltage threshold value, the no-load voltage corresponding at least to a maximum ignition voltage of the ignition circuit, the computer program, when executed by a computer, causing the computer to perform:
• connecting the high-side ignition circuit terminal to the high-side current source, a and connecting the low-side ignition circuit terminal to a voltage sink terminal;
• activating the high-side current source;
• determining a difference voltage signal between the high-side ignition circuit terminal and the low-side ignition circuit terminal;
• and
• ascertaining an ignition circuit resistance using the difference voltage signal.