SU1451817A1 - Device for controlling selector switch with two interlocked outputs - Google Patents

Abstract

The invention relates to electrical engineering and m. used in automation systems. The goal is to increase reliability by eliminating the possibility of simultaneously unlocking both output controlled keys. The device contains two output controlled keys 1, 2 and a voltage limiter 3. The emitter repeaters on elements 13 and 14 form the control circuit of output keys 1, 2. On logic elements 5 and 6, the command program of the device is implemented, containing three states off, I mode, II mode. When a level O arrives at the control input, the device enters the Off state. Diodes 7 and 10 eliminate the effect of time delays determined by the parameters of elements 11 and 12. This provides a more forced transition from one state to another. 1 hp f-ly, 1 ill. e

Description

The invention relates to electrical engineering and can be used in automation and electric drive systems for controlling executive relays or electrical mechanisms.

The purpose of the invention is to increase reliability by eliminating the possibility of simultaneous unlocking of both output managed keys.

The drawing shows a functional diagram of the described device.

The device contains two output controlled keys 1 and 2, a voltage limiter 3 (reference diodes), a resistor 4 (current-setting element). Logic elements 5 and 6, which are part of the control logic with cross-links of interlocking, are connected to the time delay chains 7-9 and 10-12. The emitter followers on the elements 13 and 14 form the control circuit of the output keys 1 and 2.

On logic elements 5 and 6, the device _'s command program containing three states is turned off; I mode, II mode.

The element 15 implements the necessary delay of the moment the mode II is turned on with respect to the moment the mode I is turned off. This delay takes into account the actual performance of the executive structures.

Element 16 serves to invert the control voltage.

I

The device operates as follows.

The initial state of the device is the state. Off, which is implemented if there is a logic level 0 at the control input. At the same time, level 1 is formed at the outputs of elements 5 and 6, level 0 is formed at the outputs of elements 15 and 16, and keys 1 and 2 are locked. The corresponding actuating structures with the necessary power source connected to a common wire (and power source) of the device in question can be connected to the outputs I and II of the device.

If a signal with a logic level 1, a state of the elements of bi 16 is reversed, arrives at the control input. In this case, the key 2 receives the opening potential. The power circuit of this key through the connected actuator starts to flow current.

In the General case, the resistor 4 can be dynamically controlled according to some functional dependence, determined by the logic of the actuators.

The described interaction of elements corresponds to the state of Mode I.

At the input of element 5, the same level of logical 1 arrives after a certain delay time, determined by the parameters of elements 8 and 9, after the appearance of this level at the control input of the device. After charging the capacitor 9 to the threshold of operation of element 5, the command device on the elements 5 and 6 capsizes into the third state - Mode II.

At the output of element 5, state 0 is set, which, through the circuit, element 6 - element 16 locks the key 2. After this, after a delay time determined by the parameters of elements 11 and 12, the key 1 is opened, which has a current-collecting element common with the key 2. The state is Mode II .

When level O arrives at the control input, the device goes into the Off state, both keys 1 and 2 are closed. At the same time, diodes 7 and 10 eliminate the effects of the indicated time delays, which ensures the fastest possible transition of the device to the Off state from both the Mode I state and the Mode II state.

Suppose that during non-stationary processes, the opening electrodes of the keys 1 and 2 simultaneously received opening pulses. In this case, the current of both the key 1 and the key 2 will flow through the current-collecting element 4. This will lead to an increase in the voltage drop across the resistor 4, the polarity of which is such that partially covers both keys. Thus, the current of keys 1 and 2 cannot exceed the safe values. In addition, when using thyristor structures in the input circuits of the actuators connected to the outputs I and II of the described device, it is sufficient to choose the resistance of the resistor 4 so that it is impossible to switch them on simultaneously when the opening pulses arrive simultaneously at keys 1 and 2.

Claims (2)

Claim 1. A switch control device with two mutually interlocked outputs, comprising a control logic with cross-locking interlocking connections and two output controlled keys, characterized in that, in order to increase reliability by eliminating the possibility of simultaneously unlocking both output controlled keys, the output controlled keys are connected according to the scheme of a differential amplifier with a common current-carrying element, which is simultaneously included in the power and control circuits of these keys, and in the control circuit of each On the output of the controlled key, a voltage limiter ⁸ is introduced. 2. The device pop. 1, characterized in that the output controlled keys are made in the form of transistors, the emitters of which are combined and connected through a common current-setting resistor to a common output of the power and control circuit of the device, and the voltage limiter is made in the form of a chain of several diodes connected in series in the forward direction connected between the base of the indicated transistor and the common output of the 2Q howl and the control circuit of the transistors.