JPH0328577Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Overview of the Field] The present invention relates to a pseudo-noise generator that generates electromagnetic noise to test the malfunction of electronic equipment, and more specifically relates to the structure of a relay that discharges coaxial line charging voltage.

[Contents and problems of conventional technology]

Conventionally, this type of pseudo-electromagnetic noise generator has a charging resistor 2 and a relay 3 connected in series to a DC high-voltage power supply 1, as shown in the circuit diagram shown in FIG. The outer conductor of the coaxial line 4 is connected to the power source 1, and the other end of the core wire 5 of the coaxial line 4 is connected to the terminating resistor 7 via a relay 6.
One end of the terminating resistor 7 is connected, and the other end of the terminating resistor 7 is connected to the coaxial line 4.
a coaxial termination connected to the outer conductor of the

Relay 6 is off, relay 3 is turned on and coaxial line 4 is charged. After charging, relay 3
is turned off and relay 6 is turned on, discharging from coaxial line 4 to termination resistor 7 and load 8, and applying pseudo noise to load 8.

The pseudo-noise voltage waveform caused by the discharge of the coaxial line charging voltage has an extremely short rise time, less than 1 ns (nanosecond). The relay 6 is a high-voltage relay, and has a coaxial structure shown in FIG. 5 to prevent unnecessary vibration from occurring following a steep rise in the waveform of the pseudo noise. Fifth
In the figure, 9 is a reed switch (mercury contact reed switch), 10 is a metal tube, 11 is a plug (connector fitting), and 12 is an insulating resin.

Since the relay 6 generates a stable noise for a long time, it is necessary to replace it frequently depending on the condition of the contact points.

Since high-voltage relays are expensive, it is desirable to use inexpensive low-voltage relays.

Now, consider the case where two relays are connected in series instead of one relay 6. An equivalent circuit diagram of the pseudo noise generator in this case is shown in FIG. C ₀ is the connection capacitance, which is the capacitance between the connection wire of the two relays 6 ₁ and 6 ₂ connected in series and the outer metal tube. The area within the dashed line frame in Figure 6 is equivalent to the 7th line.
As shown in the circuit diagram of fig. C ₁ and C ₂ are shown in the circuit diagrams of relays 6 ₁ and 6 ₂ , respectively. C ₁ and C ₂ are the contact capacities of relays 6 ₁ and 6 ₂ , respectively, and are 0.2 to 10PF.
That's about it.

When the relays 6 ₁ and 6 ₂ have the coaxial structure shown in FIG. 5, a coaxial cable is usually used to connect them in order to avoid generating vibration waves in the waveform of pseudo noise. Coaxial cable is usually 100~200PF/m
It has a certain capacity, and requires a certain length (for example, 10 cm or more) for connection.

In Figure 7, C ₁ and C ₂ are 1PF, and C ₀ is
Assuming 15PF, C ₀ and C ₁ are in series, so E ₁ ≒ C ₀ / C ₁ E ₀ , so E ₁ ≒ 15E _0. Now, if E is 10KV, E = E ₀ + E ₁ . Therefore, E ₀ ≒ 0.6 (KV), E ₁ ≒ 9.4
(KV).

In other words, in the method of connecting the relays 6 ₁ and 6 ₂ using coaxial cables, it is necessary to use a high-voltage relay for the relay 6 ₁ . That is, the above result requires that the generation of capacitance due to the connection lines between the relays connected in series be minimized as much as possible.

As explained above, in the conventional structure in which two coaxial relays are connected in series using a coaxial cable, it is difficult to significantly reduce the withstand voltage of the relay used on the coaxial line side, that is, the first stage. It was hot.

[Purpose of invention]

An object of the present invention is to provide a relay structure that uses a plurality of low voltage relays and does not disturb the waveform of pseudo noise.

The present invention is a pseudo-noise generator equipped with a coaxial charging section and a coaxial termination section, in which multiple reed switches are connected in series to the relay at the coaxial termination section using a single conductor wire, and multiple reed switches are connected in series using a metal exterior case. This is a pseudo-noise generator with a coaxial structure that is integrally covered with the following.

[Structure of the idea]

By connecting multiple reed switches in series with a short single conductor wire, the connection capacitance is at least smaller than the contact capacitance of the reed switch, reducing the withstand voltage of the reed switch used in the first stage, and making it possible to connect multiple reed switches in series. The integral coaxial structure prevents disturbance of the waveform of pseudo noise.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing one embodiment of a coaxial termination relay used in the pseudo noise generator of the present invention.

Two reed switches (mercury contact reed switches) 9 ₁ and 9 ₂ are arranged vertically, and the movable contact terminal 9 _1a of the upper reed switch 9 ₁ and the normally open contact terminal 9 _2b of the lower reed switch 9 ₂ are connected vertically. Cylindrical parts with slits are provided at both ends, and a short connection is made using a bent single conductor wire 13, and the normally open contact terminal 9 _1b of the upper reed switch 9 ₁ and the center conductor of the connector are connected with the bent single conductor wire 13. , After connecting the movable contact terminal 9 _2a of the lower reed switch 9 ₂ and the connector center conductor with a straight single conductor wire 13, the reed switches 9 ₁ and 9 ₂ are molded into a circle with a wireless resin 12. The relay has a structure in which the columnar body is covered with a metal exterior case 14 having connector fittings 11 at both ends. Reference numeral 15 denotes a drive coil for simultaneously operating the reed switches 9 ₁ and 9 ₂ .

Since this is a relay in which two reed switches 9 ₁ and 9 ₂ are connected by a short single conductor wire 13, the connection capacitance C ₀ (see FIG. 7) is sufficiently smaller than that when connected by a coaxial cable. For example, if the contact capacitances C ₁ and C ₂ of the reed switches 9 ₁ and 9 ₂ are 1PF, and the connection capacitance C ₀ is reduced to 0.5PF, then from FIG. 7, C ₁ E ₁ = (C ₀ + C ₂ )E ₀ holds, so
E1=0.5+1/ _1E0 . If E is 10KV, then E=E ₁ +E ₀ so that E ₀ =4 (KV) and E ₁ =6 (KV).

That is, by using a reed switch ₉₁ with a withstand voltage of 6 KV and a reed switch ₉₂ with a withstand voltage of 4 KV, a relay with a withstand voltage of 10 KV can be constructed.

In the example, the case of 2-stage series connection was shown, but 3 stages were connected in series.
It is also possible to connect stages in series, and the contact capacity can be changed as described above.
C ₁ , C ₂ , CC are 1PF, connection capacitance C ₀₁ , C ₀₂ is
Assuming 0.5PF, E ₀ is 10KV, the 1st stage, 2nd stage, and 3rd stage reed switches each have a withstand voltage.
A relay with a withstand voltage of 10 KV can be constructed using one with a withstand voltage of 4.7 KV, a withstand voltage of 4.2 KV, and a withstand voltage of 1.1 KV.

FIGS. 2 and 3 are a longitudinal sectional view and a plan view of another embodiment of the relay used in the present invention.

In FIG. 2, the metal exterior case consists of an upper closed-end case body 16 and a bottom plate 17, each having an oval cross section. The case body 16 is provided with a partition plate 18 in the short diameter direction up to the vicinity of the bottom opening end, and two through holes are provided on both sides of the partition plate 18 in the upper closed end surface to accommodate the plug (connector fitting) 11. is connected. (See Figure 3) Two reed switches 9 ₁ and 9 ₂ are placed side by side, and their movable contact terminals 9 _1a and 9 _2a are connected by a U-shaped single conductor wire 19 having a slit tube at the end. A reed switch assembly is made by connecting the connector center conductor to the normally open contact terminals 9 _1b and 9 _2b with the bent single conductor wire 13. This assembly is housed in the case body 16 so that the connector center conductor is in the center of the connector fitting (connector fitting) 11, and
After filling with disconnection resin 12, a bottom plate 17 is fixed to the opening of the case body 16 to form a relay with an integrated coaxial structure.

In this structure, the conductor single wire 19 is somewhat long, so assuming that the connection capacity is 1PF (contact capacity
Assuming that C ₁ and C ₂ are 1PF and E is 10 KV), the withstand voltage required for the first stage reed switch 9 ₁ is 6.7 KV, and the withstand voltage required for the second stage reed switch 9 ₂ is 3.3 KV.

[Effect of idea]

As explained above, the relay used in this invention is inexpensive because it connects multiple reed switches in series with short single conductor wires to reduce the contact capacitance, and uses inexpensive low-voltage switches to construct a high-voltage relay. Since it has a coaxial structure that is integrally covered with a metal exterior case, it does not disturb the waveform of the pseudo noise. Therefore, it is possible to provide an inexpensive, reliable, high output pseudo noise generator, and it is possible to replace the relay. The effect of reducing costs compared to conventional methods is remarkable.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a relay structure used in the pseudo noise generator of the present invention. FIGS. 2 and 3 are longitudinal cross-sectional and plan views showing other embodiments of the relay. FIG. 4 is a circuit diagram of a conventional pseudo noise generator. FIG. 5 is a longitudinal sectional view showing an example of a conventional relay. FIG. 6 is an equivalent circuit diagram of the pseudo noise generator according to the present invention. FIG. 7 is an equivalent circuit diagram of the relay at the coaxial termination section in FIG. 6. 1...DC high voltage power supply, 2...Charging resistor, 3,
6, 6 ₁ , 6 ₂ ... Relay, 4 ... Coaxial line, 5 ...
Core wire, 7...Terminal resistor, 8...Load, 10...Metal tube, 9, 9 ₁ , 9 ₂ ...Reed switch, 9 _1a ,
9 _1b , 9 _2a , 9 _2b ... Contact terminal, 11 ... Junction plug (connector metal fitting), 12 ... Disconnected resin, 13, 19
...Single conductor wire, 14...Metal exterior case, 15...
... Drive coil, 16 ... Case body, 17 ... Bottom plate, 18 ... Partition plate, C ₀ ... Connection capacity, C ₁ ,
C ₂ ……Contact capacity.

Claims (1)

[Scope of utility model registration request] A coaxial charging part is formed by connecting one terminal of a core wire of a coaxial line having a predetermined length to one end of a DC high voltage power source via a charging resistor, and connecting the outer conductor of the coaxial line and the other end of the power source. , comprising a coaxial termination section in which the other terminal of the core wire is connected in series with a terminating resistor via a relay, and the other end of the terminating resistor is connected to the outer conductor of the coaxial wire. In the pseudo noise generator, the relay connects multiple reed switches in series using a single conductor wire, and has a coaxial structure in which the reed switch part is integrally covered with a metal exterior case, and a plug is attached to the input/output part of the reed switch. , a pseudo noise generator characterized by having a structure that is easy to install and remove.