Landis & Gyr Technology Innovation Ag

Siemens Building Technologies Ag

Klaus Bott

Eckhard Schwendemann

Alexander Diebold

Jürgen Hoffmann

Bernd Schukraft

Reiner Kind

The invention relates to a flame-monitoring device in which an a.c. input voltage (U) is limited to a voltage limit (U) by means of a voltage limiter (). Said voltage limit (U) is applied to a flame sensing device () which operates by means of the rectifying effect of a flame, and through which a current (i) flows, especially when a flame () is present. An asymmetric voltage limit (U) can be defined by said voltage limiter (), said limit being then applied to the sensing device ().

Flame-monitoring device

An angular position change of the linearly driven drive system is proportional to its particular running time. In the process there is determined a desired value of the running time of the drive system belonging to a desired-value angular position (.alpha..sub.S), the drive system is thereupon started and its running time is measured and, when a measured value of the running time is equal to the determined desired value of said running time, the drive system is stopped. By this process the dependability of the drive system is improved and the costs of the latter are reduced.

Process for the position detection of a linearly driven drive system

An automatic firing arrangement (1) has an apparatus for actuating a fan which is driven by a controllable-speed asynchronous motor (2). The apparatus includes a frequency converter (3) with which the speed of rotation of the asynchronous motor (2) is controllable, switching devices (6.1; 6.2; 6.3) by which the asynchronous motor (2) can be temporarily separated from the power supply for a predetermined period of time, and a measuring means (5) with which the speed of rotation and the direction of rotation of the asynchronous motor (2) can be detected by way of the generator action thereof in said period of time.

Apparatus having an automatic firing arrangement

Information appearing in the form of analog low-voltage signals (V.sub.1 ;V.sub.2) on call lines (ML1;ML2) which represents the states of switchgears (2.1;2.2) is conveyed in parallel to a circuit block (4). The information is digitalized at certain points in time and in accordance with a predetermined voltage level as binary values '0' or '1' and is transmitted in series to a control logic unit (1). The circuit block (4) is preferably a plurality of shift registers in cascade connection. Each call line is coupled via a coupling element (3.1;3.2) to the circuit block (4) so that the circuit block (4) is not destroyed even when overvoltages occur. In the closed state of a switchgear (2.1;2.2), a signal voltage (U.sub.1 ;U.sub.2) with changeable course appears at the corresponding input (4.1;4.2) of the circuit block (4). In the open state of a switchgear (2.1;2.2), the signal voltage (U.sub.1 ; U.sub.2) is a uniform signal (U.sub.1 ;U.sub.2). The digitalization is effected by means of a synchronization device (8) at points in time when the level of the changeable signal voltage (U.sub.1 ;U.sub.2) is clearly different from the level of the zero-point voltage (G). These controls are especially well suited to control an oil or gas burner in continuous operation.

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Durmersheim, Germany

Klaus Bott