CS245186B1 - Connecting a set of AC signal carriers - Google Patents

Abstract

The set of transmitters is intended to replace neutral multi-contact relays of the 1st safety class in logic circuits when excluding contacts and moving parts. The transmitters, consisting of single-stage transistor amplifiers with transformer outputs and equipped with PNP and NPN transistors in a common emitter connection, are connected by their collector circuits to buses powered by a certain polarity from a regulated source depending on the presence of a control current. In the absence of a control current, the buses are switched to an external source with reversed polarity. The connection principle is described when using contacts of two relays; in practice, transistor switches are used. The connection ensures safe manifestation of faults in the set of transmitters, especially when breakdown of transitions in transistors.

Description

BACKGROUND OF THE INVENTION The present invention relates to a centrally controlled array of transistor amplifiers for the individual transmission of partial AC signals by individual amplifiers.

In automation technology, signal transducers generating logic functions are widely used. In addition to wiring with electromechanical relays, solutions with contactless elements such as transcombinations, eg ferritotransistor elements, are known. Especially important is the use of these elements in logic circuits with the required high operational reliability and fail-safe performance.

A characteristic feature of known elements is the realization of a single logic function, eg the creation of the logical product of two elements. For a multiple logical product, the number of elements is therefore unbearably increasing.

SUMMARY OF THE INVENTION The present invention provides an array of AC transducers, consisting of single-stage transistor amplifiers with transformer outputs, wherein the collector-emitter circuits are powered from connected polarity bus bars to a controlled source excited by the control current, or polarity aběrnic. In the first case, the controllable power supply is connected via the closed contact of the quiescent relay, both relays being energized by the controllable power supply. Both relays are replaced by switching transistors for practical use.

The arrangement according to the invention results in a set of transmitters of individual AC signals co-controlled by the control current of the regulated source. In the presence of a control current, AC signals are transmitted from the inputs to the outputs of those transmitters that contain NPN transistors. Ports with PNP transistors do not transmit input signals in a given situation. In the absence of control current, the transmission ratios will be reversed.

BRIEF DESCRIPTION OF THE DRAWINGS The attached drawings show the principle of connection of the parts of the transmitter assembly according to the invention. Fig. 1 shows the connection using relay contacts; Fig. 2 shows a variant with transistor switches.

In FIG. 1, the control current 6 is fed to a regulated power supply 2. From its output terminals, both the relay windings 2 and 2 are controlled, and the bus 8 is connected to the positive terminal and the bus 2 to the negative terminal. Resources 2

The negative terminal of the external power supply 6 is disconnected from the other end of the bus 6 in the presence of the control signal 2 by an open contact of the energized quiescent relay 2, while the other end of the bus 2 is connected to its positive terminal. Fuse 2 is inserted between power supply 6 and bus »§ ·

Shown two ports £ 0, respectively. 11, the collector-emitter circuits are connected to the buses 2. The individual AC signals are applied to the input terminals 12 and 12, respectively.

and the output signals are drawn from terminals 14 and 14, respectively. £ 2.

With the positive polarity of the bus 8, the transistor in the transmitter 80 is a conductive and alternating input signal and is amplified to the output terminals 60. If the transmitter ££ mounted complementary transistor, the input signal from the terminals 2 £ ⁸⁸ at a given polarity of the bus to the output terminal 15 does not migrate. In the absence of control current £, both relays 2 2 2 drop out, and the bus 24 is connected to an external power supply 6.

The bus 2 will now be positive, the bus 6 will be negative, and therefore the transmitter 80 will be output without a signal and the transmitter 11 will in turn transmit the signal.

FIG. 2 shows the use of contactless switches ^and 2Λ 2Δ P ^ro switching the polarity of the bus 2 »£ · controlled switching circuit provides a level - comparator ££.

245 ’

To the input terminal 2 is connected £ stele positive reference voltage input terminal is connected § £ e positive terminal of the second controllable resources in the absence of the control current £ the output voltage of the controllable source and zero comparator £ 6 supplies a positive output voltage that maintains the switch ⁱⁿ 2Δ and a switch 5A in a non-conductive state. The busses 16 are connected to an external power supply 6. When the control current 6 is present, the terminal voltages of the controllable power supply i increase to a value corresponding to the reference voltage, the output voltage of the comparator 16 changes to negative. The busses 6, 8 are thus connected to the regulated source 6.

The principle of wiring ensures safe operation of the device in case of possible failures. E.g. collector-emitter breakdown in the transmitter itself results in non-transmission of the input signal to the output, breakdown in the bus switches Zk resp. 9A is converted to a bus power loss after the fuse 2 or fuse is short-circuited between sources 2 and 6, and the like.

The set of transmitters according to the invention can be considered as the contactless equivalent of a safety class 1 neutral relay with a series of changeover contacts used, for example, in railway signaling equipment.

Claims (3)

CLAIMS 1. Connection of a plurality of AC transducers of a certain frequency depending on a control current, wherein each transducer formed by a single-stage AC amplifier comprises a transistor coupled to a common emitter, in whose collector circuit a transformer is drawn to output an output signal. of the control current (1) the energized regulated power supply (2) is connected by a negative terminal on the bus (3) and a positive terminal on the bus (4) via the closed contact of the working relay (5). 6) is connected by a positive terminal to the bus (3) via a fuse (7) and a negative terminal through the fuse (8) to a bus (4) via an open contact of the rest relay (9) also controlled by a regulated power supply (2); collector - emitter circuits in all transmitters (10) resp. (11), with input terminals (12) resp. (13) and output terminals (14), respectively. (15) are connected between the buses (3) and (4). 2. The set of transmitters according to claim 1, characterized in that the working relay (5) is formed by a switching transistor (5A) and the quiescent relay (9) is made by a complementary switching transistor (9A) with bases connected to the comparator output (16). the variable input voltage at the terminal (18) connected to the positive pole of the controllable power supply (2) is compared with the constant reference voltage applied to the terminal (17). 3. Connection of a set of transmitters according to items 1 and 2, characterized in that one group of transmitters contains PNP transistors and the other group of NPN-type transistors,