Dbt Automation Gmbh

Caterpillar Global Mining Europe Gmbh

Helmut Hermann

Jens Titschert

Emmanuel Charruau

Johannes Wesselmann

Markus Lenzing

Karsten Schwinne

Jorg Wagner

Johannes WEßELMANN

An intrinsically safe connection unit with a network interface for intrinsically safe appliances in explosion-risk areas, having a housing, a voltage supply connection, plug connection for connecting an intrinsically safe appliance via a transmission cable, and a decoupling circuit. For allowing even a multiplicity of network subscribers to be connected in the explosion-risk area with less wiring complexity, a plurality of plug connections of the same type are provided as network interface, each being preceded by a separate decoupling circuit, and the voltage supply connection builds a central feed connection with separate supply cores for each plug connection each having at least two plug contacts for data communication and at least two plug contacts for supplying power to the connectable appliances via the transmission cable. The invention relates also to a Controller and a network interface for use therewith.

Intrinsically safe connection unit with a network interface, intrinsically safe appliance and network interface for it

A method and a circuit arrangement () for the measurement of earth leakage in intrinsically safe current feeds to electronic control units () for underground mining installations and machines, whereby at least one earthed control unit is connected to the two intrinsically safe potentials of an intrinsically safe direct current supply () and at least one earth leakage sensor () is provided for earth leakage measurement with which steps of the periodical application of a test potential (U) from an intrinsically safe switchable test voltage source () to an RC-element (), isolated from earth () by means of decoupling capacitors (C, C), measurement of the charging or discharging current behaviour of the RC-element () after each switching of the test voltage source () and comparison of the measured charging or discharging behaviour with stored reference data.

Method and circuit arrangement for measuring earth leakages in intrinsically safe current feeds

The warning tone transmitter ( ) according to the invention has a piezoelectric horn element ( ) with two input connectors ( ) for the application of the supply voltage at a determined frequency and has a circuit arrangement ( ) fed from the current supply, which generates the supply voltage. In order to be able to receive confirmation that the horn signal is actually generated by the warning tone transmitter ( ) and in order to be able more easily to calibrate the warning tone transmitter ( ) such that it is driven at its resonant frequency the piezoelectric horn element ( ) has an additional output connector ( ), which, when the horn element ( ) is fed with the supply voltage, generates an answering signal taken to the circuit arrangement ( ) if the piezoelement is actually oscillating. The magnitude of the answering signal is a value for the sound volume of the warning tone transmitter ( ).

Warning tone transmitter

A method and apparatus for remotely controlled operation of one of several control devices ( ) for support frames in underground mining in which the control device ( &prime;) to be actuated is selected by means of an infra-red remote operation and then the transmission of control data between a remote controller ( ) and the selected control device ( ) is effected by radio transmission. The remote controller, ( ) has not only a radio transmitter ( ) and the control devices ( ) a radio receiver ( ), but each control device ( ) is additionally provided with at least one infra-red receiver ( ), whereby by an infra-red data transmission, the control device ( &prime;) to be actuated is first deliberately selected by the remote controller ( ), before the control data is then subsequently transmitted by radio.

Growing community of inventors

Bochum, Germany

Helmut Hermann