FIELD: measuring equipment.
SUBSTANCE: protection device of an aircraft turbomachine calculator from speed measurement errors, containing in the adjustment channel a speed sensor for the turbomachine gearbox shaft, the first speed measurement circuit and speed adjustment circuit. In the adjustment channel the device contains a speed sensor for the turbomachine gas generator shaft, the second speed measurement circuit and turbomachine shutdown control circuit. Both speed sensors are two sensors, which are installed opposite two phonic wheels of different processes and having a different number of teeth. The first and second speed adjustment circuits compare a frequency signal with a minimum threshold and deliver the first and second speed issue detection signals, when the measured frequency is lower than the minimum threshold. The device additionally includes a cross-check circuit of the first and second speeds, obtained from the first and second speed measurement circuits, respectively. The cross-check circuit delivers the third speed issue detection signal in case of an abnormal deviation between the first and second speeds. The frequency signals are various frequency signals. According to the method of protection of the turbomachine calculator two pseudo-sinusoidal frequency signal, the frequency signals with a minimum threshold are compared and the speed issue detection signals are delivered, the speeds, delivered from the speed adjustment channel and control channel, are cross-checked, and the third speed issue detection signal is delivered, the machine shutdown is controlled in case of a speed issue.
EFFECT: improvement of the device.
11 cl, 2 dwg
