SU439918A1 - Device for channel selection based on signal priority - Google Patents

Description

one

This invention relates to the field of creating semiconductor circuits for irided electronics and telemechanics.

In multichannel signal transmission systems, the problem arises of allocating one of several channels through irisiac to prioritize the appearance of a signal in the form of a DC voltage. The purpose of the device for channel selection is that when one of the n inputs (n is the number of channels) arrives at the first time signal, o is nmnul at the corresponding output, and the other outputs are locked for the duration of the signals passing through all channels. Channel selection devices are known, comprising resistors, semiconductor transistors and diodes.

The disadvantages of such devices are high circuit complexity and lack of reliability.

To simplify the circuit and increase the reliability of the proposed device, the input channels of each channel are combined into a “separating OR” circuit connected to the base of the transistor closed in the initial state, connected according to the common emitter circuit, to the collector of which the output diodes are connected.

The drawing shows a diagram of the proposed device.

Here the input terminal has a negative polarity. For a positive polarity signal, it is necessary to change the polarity of switching on all the diodes and use an n-p- / g-type transistor.

The input diodes D form an OR separation circuit which is connected via a resistor R (connected to the base of the transistor Tr. A bias resistor is connected between the base and the emitter of the transistor. The device inputs are connected to the corresponding channels of the controlled multichannel system. A resistor , and the output diodes Dg of all channels are connected to the collector of the transistor Tr.

The device works as follows.

In the idle state, the control transistor Tp is locked by zero potential, supplied to its base through the resistor R, when the first negative signal is detected in any channel, this signal goes through the resistor R to the corresponding output and through the input diode D supplies the base of the transistor Tp . After a time t equal to the transistor's own open time, the transistor opens and short-circuits the output signal from the device. All exits are blocked. The ratio between the value of mn resistance resistors Re, and R

where n -

is defined by the expression

the number of channels, ip is the minimum possible current gain factor of the transistor used. In this state, the device remains until the signals from all inputs disappear. The duration of the existence of a signal at the output of the circuit is equal to m and depends on the speed of the transistor used. If desired, this time can be increased by shunting a resistor with a capacitance, which will slow down the opening of the transistor.

If at several inputs of the device the signals appear simultaneously (within the time t), they cause the appearance of pulses at the corresponding inputs. As can be seen from the drawing, only passive elements are used in the circuit of each channel, and for

device operation does not require an electrical source. High reliability of operation is provided both by the simplicity of the circuit and the impossibility of operating uncertainty with simultaneous unavailability of signals from several channels.

Subject invention

A device for channel selection but a sign of signal priority, containing a resistor in the value of each channel, input and output diodes, as well as a control transistor connected according to a circuit with a common emulator, which is designed to amplify the circuit and increase reliability , the input diodes are combined into a "separating OR" circuit connected to the base of the closed in the initial state of the traisistor, to the collector of which the output diodes are connected ..

Vlod1

BUT

Vlod p

Bbtxod 1

A2

Botxod n