JPH03236622A - Impulse generating circuit - Google Patents

Abstract

PURPOSE:To generate an impulse with a momentarily large power by causing a timewise deviation in a change timing of a drive pulse output of 1st and 2nd driver circuits and supplying a surge current to a series circuit comprising of a capacitor and a radio wave radiation load. CONSTITUTION:When a pulse is inputted from a pulse generator 10, an output signal having a delay time D is outputted respectively from a delay element 1 and driver elements 2, 3. When the pulse is inputted at a time t1, an output level of the element 3 changes from L to H at a time t2 after the lapse of the time D. On the other hand, since an output change of the element 2 is delayed further by the delay time D in the element 1, the output level changes from H to L at a time t3 after the lapse of a time 2D. An instantaneous surge of discharge current flows to the capacitor 5 at times t2, t3. On the other hand, the instantaneous surge of discharge current flows at a time t5 when both the outputs of the elements 2, 3 are at L and at a time t6 when the element 2 goes to H and the said current flows also to an antenna load 4 as a load current and an electromagnetic wave including lots of harmonic waves is radiated from the antenna.

Description

[Detailed Description of the Invention] [Summary] Regarding impulse generation circuits that can be used for immunity tests, etc., we have developed a simple and compact circuit that can generate instantaneous high-power impulses such as surges containing many harmonics. A pulse oscillator that generates a large force pulse, a first driver circuit that outputs a drive pulse in response to the large force pulse, and a drive pulse of the first driver circuit in response to an input pulse, with the aim of realizing it with a circuit configuration. a second driver circuit that outputs drive pulses of opposite polarity, a delay circuit that delays the drive pulse of one driver circuit than the drive pulse of the other driver circuit, and output terminals of the first and second driver circuits. It comprises a series circuit of a radio wave radiation load and a capacitor connected between them.

[Industrial Application Field] The present invention relates to an impulse generation circuit that can be used for immunity tests and the like.

Immunity testing is a test in which interference radio waves are applied to electronic equipment to determine whether or not the electronic equipment malfunctions. The interfering radio waves used in this test must be electromagnetic waves containing many harmonics, and it is necessary that such interfering radio waves can be generated by a simple and compact circuit.

[Prior Art 1 A conventional immunity test method is shown in FIG. Fifth
In the figure, 21 is a sine wave oscillator, 22 is a wideband power amplifier for power amplifying the oscillation output of the sine wave oscillator 21, and 23
2 is an antenna that converts the oscillation output amplified by the power amplifier 22 into a radio wave and radiates it, and 24 is an electronic device to be tested.

In this conventional method, the oscillation frequency of the sine wave oscillator 21 is successively varied to simulate an electromagnetic wave containing a large number of harmonics, and the electromagnetic wave is radiated from the antenna 23 to the electronic device 24.

[Problems that 3R Ming is trying to solve]] The interfering electric field used for the immunity test needs to be a strong electromagnetic wave containing many harmonic components, but in the conventional test method, the oscillation of the sine wave oscillator 21 The test was carried out by changing the frequency sequentially, so the test was time-consuming and could not be said to be a perfect test. Test equipment also requires a sine wave oscillator that can vary the frequency over a wide range and a wideband power amplifier with a wide band, but these devices require large circuits and are expensive.

The present invention has been made in view of the above circumstances, and its purpose is to provide a circuit that can generate instantaneous large power impulses such as surges containing many harmonics with a simple and compact circuit configuration. It is about realization.

]Means to solve the problem 1 FIG. 1 is a diagram explaining the principle of the present invention.

The impulse generation circuit according to the present invention includes a pulse oscillator 41 that generates input pulses, a first driver circuit 42 that outputs drive pulses according to the input pulses, and a drive circuit 42 that drives the first driver circuit 42 according to the input pulses. A second driver circuit 43 that outputs a drive pulse of opposite polarity to the pulse, a delay circuit 44 that delays the drive pulse of one driver circuit than the drive pulse of the other driver circuit, and the first and second drivers. It comprises a series circuit of a radio wave radiation load 45 and a capacitor 46 connected between the output terminals of the circuit.

[Operation] When the circuit is configured as described above, the first driver circuit 4
There is a time lag in the change timing of the drive pulse output of the second driver circuit 43 and the drive pulse output of the second driver circuit 43, and at this change timing, a surge-like charging/discharging current flows through the capacitor 46, and this charging/discharging current emits radio waves. It also flows to the load 45. This makes it possible to supply a surge-like, large-power impulse current containing many harmonics to the radio wave radiation load.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows an impulse generating circuit as an embodiment of the present invention. In Figure 2, 6.7 manpower is required. This input pulse is split into two, one being input to the inverting driver element 2 via the delay element 1, and the other input directly to the driver element 3. Inverted driver element 2 is NOT
The driver elements 2 and 3 are both circuits that can handle large amounts of power.

The output of this driver element 2 is transmitted to the load 4 via an output terminal 8.
The output of the driver element 3 is connected to one end 52 of the capacitor 5. Further, the other end 51 of the capacitor 5 is connected to the other end of the load 4 via the output terminal 9. The load 4 is composed of an antenna circuit that radiates electromagnetic waves.

The operation of this embodiment circuit will be explained below with reference to FIGS. 3 and 4. Here, FIG. 3 is a signal waveform diagram of each part of the example circuit, (1) is an input pulse, (2) is an output pulse of delay element 1, (3) is a drive pulse output from driver element 2, ( 4) is the drive pulse output from the driver element 3, (5) is the output voltage at the terminal 9, and (6)
is the charging/discharging current of the capacitor 5. Here, regarding the charging/discharging current of the capacitor 5, the current flowing into the terminal 51 side is defined as a charging current, and the current flowing out from the terminal 51 is defined as a discharging current. FIG. 4 is a diagram illustrating the output states of the elements 2 and 3 and the charge/discharge state of the capacitor 5 at each timing.

Here, the signal delay times in delay element 1 and driver element 2.3 are each assumed to be D. When a pulse is input from the pulse generator 10, these delay elements 1 and driver elements 2
．． 3, the output signal is output with a time delay, and the time chart at that time is shown in (1) in Figure 3.
(2), (3), and (4).

If a pulse is now applied manually at time tl, then at time t2 after a period of time has elapsed, the output of the driver element 3 will be “
Changes from “L” to “H”.

On the other hand, since the output change of the inverting driver element 2 is further delayed by the delay time of the delay element 1, it takes time 2 from the pulse input.
At time t3 after D has elapsed, the output changes from "H" to "L".

As a result, until time t2, as shown in FIG. 4A, the output of the inverting driver element 2 is "H".
Since the output of terminal 3 is “L”, capacitor 5 is connected to terminal 5.
Positive charge is stored on the 1 side.

In the subsequent period from time t3 to t4, as shown in FIG. 4B, the output of the driver element 3 becomes "H"', so that
At time t3, the voltage on the terminal 51 side of the capacitor 5 instantaneously rises above Vcc, and the positive charge on the terminal 51 begins to be discharged via the inverting driver element 2 to the power supply circuit Vce side.

Furthermore, at time t4, as shown in FIG. 4C, the output of the inverting driver element 2 becomes "L" and the output of the driver element 3 becomes "H", so the power supply circuit from the capacitor 5 to the inverting driver element 2 side A discharge current continues to flow to the Vce side, and eventually the capacitor 5 becomes negatively charged on the terminal 51 side.

Next, the input pulse falls at time t4, and this time t4
At time t5, when a period of time has elapsed, the output of the driver element 3 changes from "H" to "L", and at time t6, a further period of time has passed since then, the output of the inverting type driver element 2 changes from "H" to "L".
It changes from “L” to “H”.

As a result, during the period from time t5 to time t6, as shown in the fourth diagram, the outputs of the inverting type driver element 2 and the driver element 3 both become "L", and at the instant of time t5, the outputs of the terminal 51 of the capacitor 5 become "L". Since the voltage of the capacitor 5 is lowered, a charging current starts to flow to the terminal 51 of the capacitor 5.Furthermore, at time t6, the inverting type driver element 2 becomes "H", so that the charging current continues to flow to the capacitor 5, and eventually the fourth
Return to the state shown in Figure A.

In this way, in the example circuit, an instantaneous surge-like discharge current flows through the capacitor 5 at times t2 and t3, while an instantaneous surge-like charging current flows at times t5 and t6.
Since these surge-like charging and discharging currents flow as load currents to the antenna load 4, electromagnetic waves containing many harmonics are radiated from the antenna.

In this embodiment circuit, as the delay time of the delay element 1 is increased, the pulse width T in FIG. 3 becomes narrower, and the electromagnetic waves radiated accordingly contain more harmonics.

In addition, in this example circuit, various intensity distributions of harmonics in the radiated electromagnetic waves are created by changing the operational parameters such as the delay time of the delay element, the repetition frequency of the input pulse, and the charge/discharge time constant determined by the load and capacitor. be able to.

As described above, the circuit of the embodiment can generate electromagnetic waves having various harmonic components and their intensity distributions by changing the delay time, input pulse repetition frequency, and charging/discharging time constant as operating parameters.

Various modifications are possible in implementing the invention. For example, in the above-described embodiment, a circuit having an inverter configuration was used for the driver element 2, but the present invention is not limited to this. For example, the driver elements 2 and 3 may have the same configuration, and the delay element l
It is also possible to configure the circuit so that it is an inverter circuit. Further, instead of using the driver element 2 as an inverter, it is also possible to configure the circuit with the driver element 3 as an inverter. Further, the delay element l does not need to be a separate element from the driver element 2, and may be a circuit made integrally with the driver element 2. In short, the drive pulse output of one driver element is used to drive the other driver element. Any circuit that can delay the pulse output by a certain period of time may be used.

〔Effect of the invention〕

According to the present invention, a surge-like instantaneous high-power impulse containing many harmonic components can be generated at a desired repetition frequency with a simple and compact circuit configuration. Further, since the pulse oscillator can use commercially available small components, the circuit can be made smaller and the cost can be reduced.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a block diagram showing an impulse generation circuit as an embodiment of the present invention, Fig. 3 is a time chart of signals of each part of the embodiment circuit, and Fig. 4 is a FIG. 5 is a diagram for explaining the charging/discharging state of the capacitor of the embodiment circuit, and FIG. 5 is a diagram for explaining the immunity test method of the embodiment. In the figure, l...Delay element 2...Inverting driver element 3...Driver element 4...Antenna load 5...Capacitor 6.7...Input terminal 8.9...Output terminal 10 ---Pulse oscillator: Keep the pulse oscillator sharp.Explanatory diagram of the principle.

Claims (1)

[Claims] 1. A pulse oscillator (41) that generates an input pulse; a first driver circuit (42) that outputs a drive pulse in response to the input pulse; a second driver circuit (43) that outputs a drive pulse of opposite polarity to the drive pulse of the driver circuit (42); delay circuit (44
); and a series circuit of a radio wave radiation load (45) and a capacitor (46) connected between the output terminals of the first and second driver circuits (42, 43).