RU2239928C1 - Ac voltage generator - Google Patents

Abstract

FIELD: electronic engineering.

SUBSTANCE: proposed generator that can be used in electronic circuits for their turning on and off at desired moments on occurrence of failures or short circuits without switching power supply has master oscillator 1, first and second flip-flops 2 and 3, first and second power amplifiers 4 and 5, transformer 6, load 10, monostable multivibrator 11, control bus 12, and power supply 13. Generator provides for disconnecting power supply from load by feeding low-power signal.

EFFECT: enlarged functional capabilities, enhanced reliability.

1 cl, 1 dwg

Description

The invention relates to the field of electronic technology and can be used in electronic circuits, for example in power sources, where they need to be turned on or off at predetermined times, in case of failures or short circuit without switching power supply.

Known alternating voltage generator [1], containing the first and second power amplifiers, a saturable transformer, to the secondary windings of which a load is connected.

The disadvantage of this device is that it does not have the ability to turn it on or off at specified points in time, in the event of a failure or short circuit without switching power supply.

The closest technical solution to the proposed device is an alternating voltage generator [2], containing a master oscillator, first and second power amplifiers, a transformer and a load connected to the secondary winding of the transformer, the first and second primary windings of which are connected respectively to the outputs of the first and second power amplifiers , and the common point of the first and second primary windings of the transformer is connected to a power source.

The disadvantage of this alternating voltage generator is that it does not have the ability to turn off the output voltage, and if the master oscillator is blocked or the generation is interrupted, the known device [2] fails, since one of the power transistors of the power amplifier will be constantly open and loaded on ohmic resistance of the primary winding of the transformer, which is very small. As a result, the power transistor and transformer will be loaded at an unacceptably large power, which leads to their failure.

The objective of the invention is the expansion of functionality by implementing control on and off of the alternating voltage generator and improving reliability by preventing failure of the device when the generation of the master oscillator is interrupted.

The solution to this problem is achieved in that the alternating voltage generator containing the master oscillator, the first and second power amplifiers, a transformer and a load connected to the secondary winding of the transformer, the first and second primary windings of which are connected respectively to the outputs of the first and second power amplifiers, and a common point the first and second primary windings of the transformer is connected to a power source, additionally contains first and second triggers and a single-shot, the input of which is connected to the output of the master g the generator and to the C-inputs of the first and second triggers, the R-inputs of which are connected to the inverted output of the single-shot, while the non-inverse output of the first trigger is connected to the input of the first power amplifier and the D-input of the second trigger, the output of which is connected to the input of the second power amplifier, inverse the output and D - the input of the first trigger are interconnected, and the control input of the master oscillator is connected to the control bus.

The drawing shows a diagram of an alternating voltage generator. In this diagram: 1 - the master oscillator, 2 - the first trigger, 3 - the second trigger, 4 - the first power amplifier, 5 - the second power amplifier, 6 - the transformer, 7 - the first primary winding of the transformer, 8 - the second primary winding of the transformer, 9 - secondary winding of the transformer, 10 - load, 11 - one-shot, 12 - control bus, 13 - power source.

In the alternating voltage generator, the output of the master oscillator 1 is connected to the input of the one-shot 11 and the C-inputs of the first 2 and second 3 triggers, R - the inputs of which are connected to the inverse output of the one-shot 11. The non-inverse output of the first trigger 2 is connected to the input of the first power amplifier 4 and D- the input of the second trigger 3, the output of which is connected to the input of the second power amplifier. The inverse output and the D-input of the first trigger 2 are interconnected, the outputs of the first 4 and second 5 power amplifiers are connected to the corresponding inputs of the first 7 and second 8 primary windings of the transformer 6, the common point of which is connected to the power source 13. The secondary winding 9 of the transformer 6 is connected to the load 10. The control input of the master oscillator 1 is connected to the control bus 12.

The alternating voltage generator operates as follows. The output signal of the master oscillator 1 with a frequency of f _{g is} fed to the input of a single-shot 11 and the C-inputs of the first 2 and second 3 triggers. Suppose that in the initial state, the first 2 and second 3 triggers were in the zero state, in which their non-inverse outputs have a low potential, and the inverse outputs have a high potential. In this case, a high level is present at input D of the first trigger 2, and a low level is present at input D of the second trigger 3. When a square-wave signal arrives from the output of the master oscillator 1 at the C-inputs of the first 2 and second 3 triggers, they pass into a single and zero state, respectively, after which a low level appears at the D-input of the first trigger, and appears at the D-input of the second trigger 3 high level. When a second pulse arrives from the output of the master oscillator 1 at the C-inputs of the first 2 and second 3 triggers, they transition to the zero and single states, respectively, after which the process of switching triggers continues.

During the switching process, the first 2 and second 3 triggers are always in opposite states. The output signals from the non-inverse outputs of the triggers are fed to the inputs of the first 4 and second 5 power amplifiers, which alternately connect the first 7 and second 8 primary windings of the transformer 6 to the power source 13, thereby forming an alternating voltage on the transformer windings. We believe that the power amplifier is turned on at a high level from the trigger output, the power amplifier is turned off at a low level at its input.

The signals from the master oscillator 1 are fed to the input of a single-shot 11, which generates an output pulse of duration τ. We choose the duration τ from the condition

where T _G is the pulse repetition period of the master oscillator 1. When condition (1) is fulfilled, the one-shot 11 will be in the mode of continuous formation of the output pulse and its output signal (we believe that when the output pulse is formed at the non-inverse output of the one-shot 11, a high potential is generated) from the inverse output is zero (low potential). This potential, arriving at the R-inputs of the first 2 and second 3 triggers, does not prevent the switching of these triggers. Thus, when the master oscillator is turned on, alternating voltage is generated on the windings of the transformer 6.

A signal is supplied to the control bus 12, which, entering the control input of the master oscillator 1, turns it on or off, that is, puts the master oscillator 1 in pulse generation mode or in the absence of generation mode. We apply to the control bus 12 a signal that puts the master oscillator 1 in the absence of generation mode. In this case, the constant potential is established at the output of the master oscillator 1, the one-shot 11 ceases to generate pulses and a high level is formed at its inverting output, which, entering the R inputs of the first 2 and second 3 triggers, puts them in the zero state. In this case, the output signals of the first 2 and second 3 triggers turn off the first 4 and second 5 power amplifiers and zero voltage is set on the windings of the transformer 6, that is, the load 10 becomes de-energized.

In electronic circuits, a situation often arises when it is necessary to disconnect part of the circuit from a voltage source, for example, if a failure occurs in this circuit or during a short circuit. The alternating voltage generator under consideration makes it possible to disconnect the voltage source from the load by supplying a low-power signal, without the need for switching circuits through which significant current flows.

Compared with the known solution [2], the proposed alternating voltage generator allows you to expand the functionality by controlling the on and off of the alternating voltage generator and increases reliability by preventing the device from malfunctioning when the master oscillator is interrupted. In the known device, in the absence of generation, one of the power amplifiers remains in the on state (one of the transistors for low-impedance load is open). In this case, a significant current flows through the power amplifier and the circuit breaks down.

The proposed set of features in the solutions considered by the authors was not found to solve the problem and does not follow explicitly from the prior art, which allows us to conclude that the technical solution meets the criteria of "novelty" and "inventive step". As elements for the implementation of the device, you can use the logical elements of digital circuits of any series, for example 564, standard power amplifiers with transistors, transformers.

Literature

1. Sources of power for electronic equipment. Handbook edited by G.S. Naivest. M .: Radio and communication, 1986, p. 351, Fig. 9.3.

2. Sources of power for electronic equipment. Handbook edited by G.S. Naivest. M .: Radio and communication, 1986, p. 417, Fig. 10.9.

Claims (1)

An alternating voltage generator comprising a master oscillator, first and second power amplifiers, a transformer and a load connected to the secondary winding of the transformer, the first and second primary windings of which are connected respectively to the outputs of the first and second power amplifiers, and the common point of the first and second primary windings of the transformer is connected to a power source, characterized in that the first and second triggers and one-shot are additionally introduced into it, the input of which is connected to the output of the master oscillator and to C-inputs of the first and second triggers, the R-inputs of which are connected to the inverted output of the one-shot, while the non-inverse output of the first trigger is connected to the input of the first power amplifier and the D-input of the second trigger, the output of which is connected to the input of the second power amplifier, the inverse output and D - the input of the first trigger is interconnected, and the control input of the master oscillator is connected to the control bus.