DE2149307A1 - TRANSDUCER - Google Patents

Description

2U9307

R. 559
September 29, 1971 Ka / Dr

ROBERT BOSCH GMBH, 7 Stuttgart 1 Transducer

The invention relates to a transducer for the capacitive detection of electrical signals in electrical lines, especially in lines in ignition systems of internal combustion engines, which are installed in motor vehicles, with a cable core serving as the first capacitor electrode, an insulating material as a dielectric and a die The metal body which at least partially surrounds the insulating material and serves as a second capacitor electrode.

Capacitive sensors of this type, which are often used to test the ignition system are installed in a motor vehicle, should have a constant capacity as possible. Also should this capacitive transmitter is not influenced by variable deposits on the transmitter or the ignition cable due to contamination and moisture stay. In addition,

- 2 - 3098U / 0672

Robert Bosch GmbH R. 559 Ka / Dr

Stuttgart 2H93Q7

Dependence on the distance to parts rait ground potential im Motor vehicle important for an accurate detection of the electrical signals.

A particularly less susceptible to external Störeiiiflüsse encoder can be formed by appropriately, that on both sides of the metal body and in close proximity to this · per a ring is mounted made of an electrically conductive material, the electrical on a given potential, particularly to ground potential of the motor vehicle overall w hold is.

Further useful refinements and advantageous developments of the invention emerge in connection with the dependent claim from the following description of an exemplary embodiment and from the accompanying drawing, which shows a transducer in a partially sectioned representation shows.

An ignition line 1 is surrounded by an insulating sleeve 2 and forms an electrical line in the ignition system of a Motor vehicle. A metal tube 3, which is coaxial with the electrical conductor, is applied to the insulating material envelope 1 is arranged. The electrical conductor 1 is used to detect the electrical signal in the line 1 as the first capacitor layer, the insulating sleeve 2 as a dielectric and the metal tube 3 as a further capacitor layer. At a good distance from the end faces of the metal pipe 3 are protective rings 4 and 5 made of electrically conductive. Material arranged. These protective rings 4 and 5 also surround the insulating material around the conductor 1. The two protective rings 4 and 5 are in an appropriate configuration

- 3 3098U / 0672

Eo "bert Bosch GmbH R. 559 Ka / Dr

Stuttgart 2 HS307

of the invention connected to one another via a shield 6, the shield 6 being connected to the ground line of the vehicle. The transducer also has a connector 7 for the electrical connection of the capacitive transducer. Between the metal pipe 3 and the shield 6 an insulating sleeve 8 is provided.

3098 U / 0672

Claims (2)

Robert Bosch GmbH E. 559 Stuttgart 2149307 claims 1.J transducer for · capacitive detection of electrical Signals in electrical lines, in particular in lines in ignition systems of internal combustion engines, the are installed in motor vehicles, with a cable core serving as the first coridisor electrode, an insulating · material shell as a dielectric and one the insulating material shell at least partially surrounding metal body serving as a second capacitor electrode, characterized in that that on both sides of the metal body O) and at a short distance from this one ring (4,5) each electrically conductive material is attached, de3? at a certain electrical potential, especially the Ground potential of the motor vehicle is held. 2. A sensor according to claim 1, characterized in that the Doss arranged on both sides of the metal bodies (3) rings (4,5) via an electric shield (6) are electrically connected together. Jf. X h U 3098U / 0672
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