SU836606A1 - Device for determining discrete circuit loadability - Google Patents

Description

(5) DEVICE FOR DETERMINING THE LOADING ABILITY OF DISCRETE CIRCUITS

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The invention applies to counter-measuring technology and can be used to determine the maximum load capacity of discrete circuits, such as multivibrator triggers.

A device is known for determining the working capacity of discrete circuits, sovereign units for generating basic and elementary contributions, a unit for determining the mean square value, load capacity distribution functions, synchronization and indication units. The disadvantage of known devices

is the complexity due to the presence of complex units of the formation of deposits of pulses and synchronization.

Closest to the proposed device for determining the load capacity of discrete circuits, which contains a switching unit for load resistors, a switch connected by inputs to the outputs of monitored discrete circuits, and an output for an indicator input, and a memory unit II.-known device determines the maximum load capacity.

discrete circuits by the method of additional load. The load capacity is characterized in the known device by the value of the load resistance at which the oscillations of the tested discrete circuit are violated. A disadvantage of the known device is the discreteness of the change in the additional load and, consequently, the accuracy of the load capacity is low. In the known device the discreteness of the resistance value of the additional load

5 is tens and hundreds of ohms, while differences in the load capacity of various discrete circuits are single and tenth ohms. In addition, a well-known device has a complex com- unit of load resistors.

The purpose of the invention is to improve the accuracy of the assessment of load capacity and simplify the device.

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This goal is achieved by the fact that a device for determining the load capacity of discrete circuits, containing a switch / connected by the first inputs to the outputs of the monitored discrete circuits.

and the output - with the input of the indicator, the memory block, the first, second and third generators, the -I element, the differentiating element, the amplifier and the trigger, the first output of which is connected to the first input of the And element, the second output through the first generator | And the amplifier - are entered switch output, the first input - with the first output of the second generator, the second output of which is connected to the second input of the switch, and the input - to the second input of the trigger and through the differentiating element, element - with the indicator output, the second input of the And element is connected to the output of the third generator a, a. output - d input of the memory block.

The drawing shows the block. Scheme of the device.

The device for determining the load capacity of the discrete circuits 1 comprises: a switch 2, a second generator 3, a trigger 4, a first generator 5, an amplifier 6, an indicator 7, a differentiating element 8, a third generator 9, an element 10 and a memory block 11.

Tei paTop 3 is configured as a blocking generator, triggered by a negative polarity pulse at the input and has two outputs, with the output pulse from the second output delayed by time relative to the pulse from the first output.

Trigger 4 is an RS flip-flop, has two separate set-up inputs, and is triggered by pulses of positive polarity.

Generator 5 is a sawtooth generator and has an operating frequency substantially below the operating frequency of circuit 1.

Amplifier 6 can be performed, for example, on a single transistor connected according to the scheme g with a common emitter, with the base of the transistor connected to the input of amplifier b, and its collector - with the output of amplifier 6. The resistance of the emitter-collector of the transistor is the load of circuit 1.

Indicator 7 is performed, for example, on a differentiating chain, a delayed multivibrator and a rectifier. It records the time from the moment when the additional load is connected to the output of the circuit 1 (switching on the transistor of the amplifier 6) until the oscillations of the circuit 1 break down. At the moment of oscillation of the circuit 1, the indicator 7 produces a positive polarity pulse.

The generator 9 contains a quartz frequency regulator to increase the accuracy and stability of the device and has an operating frequency significantly higher than the frequency of the generator 5.

The memory unit 11 is designed to recognize the number of pulses.

arriving at its input from generator 9,

The device works as follows.

In the initial position, the transistor of the amplifier 6 is closed, the output of the first circuit 1 is connected to the collector 5 of the transistor. When the device is energized, the generator 9 starts, however, the element 10 is closed and the pulses from the generator 9 to the block 11 do not pass.

When power is applied to the circuit 1, the indicator 7 captures the oscillations of the first circuit 1. At the output of the indicator, a voltage appears positive

5 polarity, which is supplied to the differentiating element 8. At the output of the element 8, a sharp-pointed pulse of positive polarity appears, which flips the trigger 4.

0 This starts the generator 5 and opens the element AND 10. From the generator 9 through the element And 10 begin to pass to the block 11 counting pulses. From the output of the generator 5 to the base

5 the transistor starts to flow linearly increasing voltage. The transistor begins to open, the emitter-collector resistance decreases. At a certain value of resistance, corresponding to the stock

0 load capacity of circuit 1,

there is a breakdown of her vibrations. At the output of the differentiating element 8, a pointed pulse of negative polarity is generated, -.

5 which triggers

generator 3. A direct pulse from the generator returns trigger 4 to its original position and as a result closes element 8, the arrival of pulses from generator 9 to block 11. Memory block 11 stores the binary code of the number of pulses received from generator 9 and proportional to the load capacity. discrete circuit 1.

The delayed pulse from generator 3, which is fed to the control input of switch 2, provides a connection to the transistor and the oscillation indicator of the following circuit 1.

A smooth change in the pass resistance of the amplifier 6 using the generator 5 and measuring the sweep time of the generator 5 from the moment of maximum resistance to the moment of resistance at which the oscillations of circuit 1 occur is eliminated by the counting method, eliminates the discreteness of the change in resistance of the additional load. This increases the accuracy in determining the load capacity and reduces the amount of equipment, which simplifies the device.

Claims (2)

1.gaskarov D.V. and others. Prediction of the technical condition and reliability of electronic equipment. M ,, Sov. radio, 1974, with. 208, fig. 11, 10. 2.Gaskarov D.V. et al. Prediction of technical condition 5 the reliability of electronic equipment, M., Sov. Radio, 1974, p. 20, Fig. 11.9 (prototype).