Control device for the actuation of switchgears according to a time program
First Claim
1. A control device comprising,a timer and control logic unit,a plurality of switchgears actuated by said timer and control logic unit according to a time program,a plurality of loads having a current supply which is controlled by the switchgears, the loads being connected in a mains-voltage network between a phase and ground in series with the switchgears,a circuit block having a plurality of inputs electrically connected to taps located in a current path between said switchgears and said loads and having an output connected to said timer and control logic unit,a plurality of call circuits, each call circuit having an output connected to an input of the circuit block and an input connected to one of said taps wherein each call circuit comprises a resistor, anda voltage supply circuit which supplies said circuit block from between said phase and said ground,wherein said circuit block comprises a plurality of protection diodes,wherein when one of said switchgears is in an open state, current flows via said protection diodes assigned to a corresponding input of said circuit block so that voltage signals from said call circuits assume a varying evolution in time at said corresponding input in relation to a reference point of said circuit block, and wherein said evolution of said voltage signals is constant when said switchgear is in a closed state, andwherein said timer and control logic unit carries out a test cycle at given points in time to ascertain the state of the switchgears.
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Accused Products
Abstract
The information on the state of switchgears (2.1;2.2) appearing on call circuits in the form of analog low-voltage signals is conveyed in parallel to a circuit block (4). The information is digitalized at given points in time in the form of binary values "0" or "1" and is transmitted in series to a microprocessor (1). Preferably the circuit block (4) comprises at least one shift register in cascade connection. Call circuits are coupled to the circuit block solely via a high-impedance resistor (3.1;3.2). The circuit block (4) is supplied by a voltage supply circuit (5) so that when one of the switchgears (2.1;2.2) is in the open state, a current flows alternately via one of the protection diodes (D1S.1,D2S.1;DIS.2,D2S.2) of the circuit block (4), and does not do so when one of the switchgears (2.1;2.2) is in the closed state. To ascertain whether a voltage (U1,U2) at the input (4.1;4.2) of the circuit block (4) is D.C. or A.C., the microprocessor (1) effects a multiple scanning within a time period of one to two network half-waves and makes an analysis of values detected consecutively in time. The control device is especially well suited for the control of art oil or gas burner in continuous operation.
14 Citations
15 Claims
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1. A control device comprising,
a timer and control logic unit, a plurality of switchgears actuated by said timer and control logic unit according to a time program, a plurality of loads having a current supply which is controlled by the switchgears, the loads being connected in a mains-voltage network between a phase and ground in series with the switchgears, a circuit block having a plurality of inputs electrically connected to taps located in a current path between said switchgears and said loads and having an output connected to said timer and control logic unit, a plurality of call circuits, each call circuit having an output connected to an input of the circuit block and an input connected to one of said taps wherein each call circuit comprises a resistor, and a voltage supply circuit which supplies said circuit block from between said phase and said ground, wherein said circuit block comprises a plurality of protection diodes, wherein when one of said switchgears is in an open state, current flows via said protection diodes assigned to a corresponding input of said circuit block so that voltage signals from said call circuits assume a varying evolution in time at said corresponding input in relation to a reference point of said circuit block, and wherein said evolution of said voltage signals is constant when said switchgear is in a closed state, and wherein said timer and control logic unit carries out a test cycle at given points in time to ascertain the state of the switchgears.
Specification