Abstract: A pipe laying device (T) connected to the jib (F) of a transport machine and carrying the pipe to be laid (T) to tight-fit it into a laid pipe (To). This coupling head (1) comprises a vertical axis (YY) swiveling link (11) and a horizontal axis (Z) tilting link (12). It comprises a guide rail (2) with a bearing (21) for positioning and attachment to the end of the laid pipe (To) and aligning the pipe to be laid (T) with the laid pipe (To) and a carrier (3) forming a telescopic tube (30) tight-fitted to the guide rail (2) and operating in relation to it; the carrier (3) carries the pipe to be laid (T) and tight-fitted to the laid pipe (To). The guide rail (2) is connected to the coupling head (1) through the telescopic tube (30).

Abstract: A pipe laying device (T) connected to the jib (F) of a transport machine and carrying the pipe to be laid (T) to tight-fit it into a laid pipe (To). This coupling head (1) comprises a vertical axis (YY) swiveling link (11) and a horizontal axis (Z) tilting link (12). It comprises a guide rail (2) with a bearing (21) for positioning and attachment to the end of the laid pipe (To) and aligning the pipe to be laid (T) with the laid pipe (To) and a carrier (3) forming a telescopic tube (30) tight-fitted to the guide rail (2) and operating in relation to it; the carrier (3) carries the pipe to be laid (T) and tight-fitted to the laid pipe (To). The guide rail (2) is connected to the coupling head (1) through the telescopic tube (30).

Abstract: A short circuit detector circuit (10) for detecting when a sensor (2), such as a tachometer sensor in automotive applications, is operating normally and when the sensor is short circuited is disclosed. The detector circuit (10) comprises a reference signal input (16) for receiving a reference signal, and a closed loop (22, 24, 12, 14, 26, 34, 32) having a predetermined loop gain (K). The closed loop has a first input coupled to the reference signal input, a first output (12) coupled to drive the sensor with a signal dependent on the input signal and the predetermined loop gain, a second input (14) for receiving a feed back signal from the sensor and a second output (36) coupled to the first input for providing an output response signal dependent on the operation of the sensor. The value of the predetermined loop gain is selected so that the output response signal is an undamped oscillation for normal sensor operation. The detector circuit (10) further comprises means (4, 50, 52, 54, 56,.