DE1958021A1 - Arrangement for triggering a bistable circuit with the aid of trigger signals whose duration is shorter than that of the trigger signals normally required - Google Patents

Description

0? 1036

Telefonaktiebolaget L M Ericsson, Stockholm 32, Sweden

Arrangement for triggering a bistable circuit with the aid of trigger signals whose duration is shorter than that of the normally "required trigger signals.

The present invention relates to an arrangement for triggering a bistable circuit with the help of trigger signals, the duration of which is shorter than that normally required Trigger signals.

In electronic process control, for example in computer-controlled I ¹ intercom systems, slow-working elements contained in the process, such as relays, are triggered by electronic circuits in the control unit that work considerably faster. In order for the short output signals of these circuits to affect the slower operating elements, one of two methods is generally used, depending on how quickly the triggered circuits must be excited. Either the short trigger signals affect bistable elements, such as flip-flops, whose output signals directly excite the slower circuits, although this method requires a large number of expensive circuits, or the trigger signals affect a bistable circuit that can be connected to various slower circuits via a selector , wherein the operation of the slow circuits takes a long time. target

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of the present invention is therefore an arrangement by means of which the slower circuits can be controlled directly by short · Trigger signals can be influenced.

The invention will be described in more detail with reference to the accompanying one Drawing described in the

Pig. 1a shows an arrangement according to the invention,

Fig. 1b is a voltage diagram for one to the arrangement shows voltage supplied according to Fig. 1a, and

FIG. 2 shows another embodiment of the arrangement according to FIG Invention shows.

In Fig. 1a, R is a bistable relay in which the bistability is achieved in a manner known per se by permanent magnets is.

One of the connections of the relay winding is connected to ground and the other via two anti-parallel connected rectifiers ^ y ^{1 1} ^ ¹⁰ - ^T y2 » ^{which are contained in} a trigger circuit S, to an alternating voltage source U, the output signal of which is shown as a function of time in Fig. 1b is shown. From this figure it can be seen that the signal changes between the amplitudes ^ U and -TJ, it being assumed that each amplitude remains present for the time required to actuate the relay. The gate electrodes of the rectifiers are also connected to the input I of the arrangement to which the short trigger signals are supplied. The rectifiers TyI and Ty2 are now alternately biased in their conducting direction, with the result that depending on the point in time at which a trigger signal is received from input I, the relay receives a current in a certain direction and depending on this current direction in one certain stable position is set. The duration of this current is determined by the time from the time the trigger pulse is received to the time the voltage changes in amplitude

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TJ is enough, this time being the actuation time of the relay must exceed. By synchronizing the trigger pulse and the positive and negative polarities of the voltage TJ when setting or resetting, a control of the slowly working. Element can be achieved.

In Fig. 2, a bistable relay R is shown, which consists of two ' Windings R1 and R2, the relay being set or reset depending on which winding is energized will. The arrangement also contains the same components as those according to FIG. 1a, but the rectifiers are parallel switched, and the rectifier Ty2 is connected to the voltage source TJ via a phase shift network PS, which is contained in the trigger circuit S. The rectifiers are therefore alternating in their conducting direction biased in the same way as in Fig. 1a, and the relay is depending on the time of receipt of the Trigger pulse at input I set or reset.

In the arrangements described above, relays were assumed as bistable elements in which the bistability is achieved magnetically, but the invention can of course can also be used in other bistable circuits in which the bistability is in some other way is achieved, e.g. electrically or mechanically.

Patent claims:

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Claims (3)

-4- T 1036 claims 1. Arrangement for triggering a bistable circuit with the help of signals whose duration is shorter than that of the normally required trigger signals, identified by a Trigger circuit (S) which is connected to an alternating voltage source (U), the half-periods of which have a duration that is at least equal to that of the normally required trigger signals, the trigger circuit consisting of two in parallel switched controlled rectifiers (Ty1 or Ty2) exists, each of which is connected to a trigger input (i) to which the short-term trigger pulses are applied, wherein the rectifiers alternate in their conducting direction during the half cycles of the AC voltage are biased and a rectifier is conductive until the end of a half cycle in which a trigger pulse has been received, the trigger circuit having two outputs connected to each rectifier and the Outputs are connected to the bistable circuit (R) which, depending on which of the outputs is energized, is placed in one of its stable states. 2. Arrangement according to claim 1, characterized in that the rectifier in the trigger circuit between the voltage source and the outputs of the trigger circuit, with one rectifier the anode and the other the Cathode are connected to the voltage source. 3. Arrangement according to claim 1, characterized in that the rectifiers are each between an output of the trigger circuit and the voltage source, one of the The rectifier is connected to the voltage source directly and the other is connected to the voltage source via a phase shift network (PS) and both rectifiers are directed to the source with the same electrode. ij fj 9 H ? Ί / 1 7 6 4