DE2936357A1 - Logic state changeover circuit - has two pole key providing feedback from logic circuit to RC-element input - Google Patents

Abstract

The circuit is intended for direct energising of relays. It has a key, whose operation energises an RC-element with its connectable logic circuit. The key (10) is of two-pole type and its actuation enables formation of a feedback circuit (20) from the logic circuit (15,16,18) to the input (E) of the RC-element (13,14). Pref. a capacitor (17) is coupled to the logic circuit. One pole of the two pole key is connected to the RC-element's input side, and the other to the RC-element's output side. The logic circuit may contain two parallel, oppositely connected inverters, both being coupled to the capacitor. The two inverters may be connectable in series by the second switching member of the key. A resistor (18) may be incorporated between the input of the first inverter and the output of the second one.

Description

Switching device

The invention relates to a switching device, in particular for switching logical states with a button, one that can be controlled by pressing the button RC element and with a logic circuit that can be switched to the RC element.

A switching device of the type mentioned is already known and is explained below with reference to FIG. 1.

This known switching device has, in addition to a button, i.

an automatically resetting switching unit, an RC element on, which can be connected to voltage by the button. Using the RC element is a logical one Connected circuit that consists of a Schmitt trigger to which a J-K master Slave flip-flop is connected. As with the known circuit the button before the control of the flip-flop must be debounced, so that the resulting The RC element prevents the flip-flop from tipping over safely to connect a Schmitt trigger afterwards. The known switching device therefore requires a comparably large effort and also has the disadvantage that, for example Relays cannot be controlled directly.

The invention is therefore based on the object of a switching device to create the type mentioned, which is simple and also a enables direct control of relays.

This object is achieved according to the invention in that the button is bipolar, and that a feedback circuit from the logical via the button Circuit to the input of the RC circuit can be produced. Preferably to the logic circuit a capacitor must be connected. The button advantageously has two switching elements which can be actuated in two positions, one switching element to the input side of the RC element and the second Scial element to the output side of the RC element, each alternatively, are switchable.

The logic circuit preferably consists of two parallel to each other lying inverters switched in opposite directions. The Invierter can use the capacitor be connected.

By pressing the button, the two inverters can be switched via the second switching element can be connected in series with one another.

A resistor is provided between the inverter, which serves to when switching the button, the lingancJ of one inverter to a defined one To hold potential.

The capacitor prevents switching due to disturbances on the load side may occur.

The switching device according to the invention can be operated with little effort and requires only a small amount of space. The Switching device according to the invention for use in devices or device front panels instead of comparably large, space-consuming switches.

The use of power inverters for those to be provided according to the invention Inverter enables the direct switching of relays or other consumers.

Illit of the switching device according to the invention is comparable simple arrangement created with little effort, when by pressing the Button the logic state present at the output can be switched.

The following is a preferred embodiment of the switching device described with reference to the drawing to explain further features. They show: Fig. 1 shows a known switching device and FIG. 2 shows the basic structure of the inventive Switching device.

The shown in Fig. 1, known switching device has a Button 1 with a switching element, which is between a predetermined potential, e.g. positive potential (+) and ground can be switched. The switching element of the button is connected to an RC circuit consisting of a resistor 2 and a capacitor 3 consists, the capacitor 3 being against ground. The output of the RC circuit, i.e. the connection point between resistor 2 and capacitor 3 is on a Schmitt trigger 4 switched, the output side a J-K master slave flip-flop 5 controls whose inputs J, K in the illustrated embodiment to positive Potential (+). A transistor 6 arranged on the output side is activated by the Flip-flop 5 is controlled in the conducting or blocking state and is required to, for example Relay or the like head for.

In the switching device shown in Fig. 1, the RC element 2 is used, 3 debouncing the button 1. The rate of rise caused by the RC element however, prevents the flip-flop from tipping over, which is why the RC element has a Schmitt trigger 4, via which the flip-flop 5 is controlled.

In order to cope with the disadvantages mentioned at the beginning with reference to FIG. To avoid the circuit explained in FIG. 1, a two-pole button is used according to the invention which is designated by 10 is used.

This two-pole button 10 has a switching element 11 and another Switching element 12, which are mechanically coupled to one another. Furthermore is accordingly ig. 1 an RC element is provided, which consists of a resistor 13 and a capacitor 14 consists, the input to resistor 13 being the input of the RC circuit and the connection between the resistor 13 and the capacitor 14 the output of the RC circuit forms.

The logic circuit consists of a first inverter 15 and one second inverter 16, the input of the second inverter 16 and the output of the first inverter 15 are connected to a capacitor 17. The outcome of the The second inverter 16 and the input of the first inverter 15 are connected via a resistor 18 connected to each other. Also, the output of the second inverter is to one Contact 19 connected, to which the switching element 12 can be controlled. The switching element 12 stands with the connection point between the first inverter 15 and the resistor 18 in connection.

According to FIG. 2, that is connected to the input of the second inverter 16 Output of the first inverter 15 via a feedback circuit 20 to the first Switching element 11 connected between a contact 21 and the input E of the RC circuit is controllable.

The operation of the switching device shown in FIG. 2 will now be described explained: In the switched-off state, the charge on capacitor 14 is the RC circuit and the charge on capacitor 17 is zero. As a result, the entrance of the second inverter 16 to zero. As a result, when the button 10 is not pressed, the input signal is activated Zero of the second inverter 16 via the switching element 11 to the input of the RC element 13, 14 transferred. The input of the inverter 15 is due to the inversion of the at the input of the second Invcrrters 16 signal zero to 1.

Dic actuation of the button 10 has the consequence that its switching element 12 is placed from contact 19 to output A of the RC circuit and the voltage of the capacitor 14 via the switching element 12 to the L input of the first inverter 15 reached. At the same time the switching element 11 is connected to the input E of the RC circuit 13, 14 connected to contact 21, i.e. separated from the RC circuit, which leads to The result is that the output of the first inverter 15 from Lingang to the RC element 13, 14 is separated. The signal at the output of the inverter 15 corresponds to the "1" after inverting the signal present at its input "0" and wira after release of the button 10 via the switch 11 to the RC member 13, 14 and transferred to the Capacitor 14 applied. The RC element is thus on after the button 10 has been released the logical value "1".

A repeated actuation of the button 10 leaves the switching elements again 11 and 12 switch to the switching position opposite to FIG. 2, as a result the value "1" previously added to the RC element is inverted in the first inverter 15 and leads to a value "0" at the output of the first inverter 15. This value. will after releasing the button 10 to the input L of the RC element 13, 14, so that the inverted value "0" is again applied to the capacitor 14.

The resistor 18 between the output of the second inverter 1G and the input of the first inverter 15 ensures that during the switching of the Switching elements 11 and 12 of the button 10 of the Lingang of the first gate 15 on one defined potential is maintained. The capacitor 17 is provided to prevent interference, which from the supply voltage via the load at the input of the second inverter 1G could be fed, prevented and not cause switching.

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Claims (7)

Claims switching device, in particular for switching locjischer States, with a button, an RC element controllable by pressing the button and a logic circuit that can be switched to the RC element, characterized in that that the button (10) is bipolar, and that a feedback circuit via the button (10) (20) from the logic circuit (15, 16, 18) to the input (E) of the RC circuit (13, 14) can be produced. 2. Switching device according to claim 1, characterized in that a capacitor (17) is connected to the logic circuit (15, 16, 18). 3. Switching device according to claim 1 or 2, characterized in that that the button (10) has two switching elements (11, 12) which can be actuated in two positions, and that a switching element to the input side (L) of the RC element (13, 14) and the second switching element (12) switchable to the output side (A) of the RC element (13, 14) is. 4. Switching device according to one of the preceding claims, characterized characterized in that the logic circuit (15, 16, 18) two parallel to each other lying, oppositely connected inverters (15, 16). 5. Switching device according to claim 4, characterized in that the two inverters (15, 16) are connected to the capacitor (17). 6. Switching device according to claim 4 or 5, characterized in that that the two inverters (15, 16) via the second switching element (12) of the button (10) are switchable in series with each other. 7. Switching device according to at least one of the preceding claims, characterized in that a resistor (18) between the input of the first Inverter (15) and the output of the second inverter (16) is switched.