JPH0311747Y2

JPH0311747Y2 -

Info

Publication number: JPH0311747Y2
Application number: JP903182U
Authority: JP
Priority date: 1982-01-26
Filing date: 1982-01-26
Publication date: 1991-03-20
Also published as: JPS58112972U

Description

【考案の詳細な説明】 (a) 考案の技術分野この考案は、抵抗・コンデンサ・コイルなどの
回路素子を測定する測定器の測定信号供給回路に
ついてのものである。[Detailed description of the invention] (a) Technical field of the invention This invention relates to a measurement signal supply circuit for a measuring instrument that measures circuit elements such as resistors, capacitors, and coils.

(b) 従来技術従来回路の一例を第１図に示す。第１図の１は
信号源、２は抵抗、３は二本巻トランス、４は測
定される回路素子、５は増幅器、６は基準抵抗で
ある。(b) Prior Art An example of a conventional circuit is shown in FIG. In FIG. 1, 1 is a signal source, 2 is a resistor, 3 is a two-wound transformer, 4 is a circuit element to be measured, 5 is an amplifier, and 6 is a reference resistor.

第１図では、信号源１の信号を抵抗２と二本巻
トランス３を介して回路素子４に加え、回路素子
４に加わる電圧を電圧端子７で測定し、回路素子
４に流れる電流を電流端子８で測定する。そし
て、電圧端子７と電流端子８の測定値から回路素
子４のインピーダンスを求める。すなわち、１〜
３が測定信号供給回路を構成し、５〜８が回路素
子４の測定回路を構成する。 In FIG. 1, a signal from a signal source 1 is applied to a circuit element 4 via a resistor 2 and a two-winding transformer 3, the voltage applied to the circuit element 4 is measured at a voltage terminal 7, and the current flowing through the circuit element 4 is calculated as a current. Measure at terminal 8. Then, the impedance of the circuit element 4 is determined from the measured values of the voltage terminal 7 and the current terminal 8. That is, 1~
3 constitutes a measurement signal supply circuit, and 5 to 8 constitute a measurement circuit of the circuit element 4.

二本巻トランス３では、各端子を次のように接
続する。すなわち、端子３１を抵抗２を介して信
号源１に接続し、端子３２を測定回路に接続す
る。そして、端子３３を信号源１側のアース点に
接続し、端子３４を測定回路側のアース点に続す
る。このように分けて接続するのは、信号源１側
と測定回路側が相互に影響し合わないようにする
ためである。 In the two-winding transformer 3, each terminal is connected as follows. That is, the terminal 31 is connected to the signal source 1 via the resistor 2, and the terminal 32 is connected to the measuring circuit. Then, the terminal 33 is connected to the ground point on the signal source 1 side, and the terminal 34 is connected to the ground point on the measuring circuit side. The reason for connecting them separately in this way is to prevent the signal source 1 side and the measurement circuit side from influencing each other.

抵抗２の抵抗値は二本巻トランス３の特性イン
ピーダンスと等しくする。これは、回路素子４を
接続すると反射波が発生するが、抵抗２にこの反
射波に対する終端抵抗の役目をさせるためであ
る。 The resistance value of the resistor 2 is made equal to the characteristic impedance of the two-wound transformer 3. This is because when the circuit element 4 is connected, a reflected wave is generated, and the resistor 2 is made to act as a terminating resistor for this reflected wave.

(c) 従来技術の問題点第１図では、二本巻トランス３を信号源１の両
端に接続しているので、信号源１に重畳するコモ
ンモードのノイズを相殺することができるという
利点がある。しかし、回路素子４が電解コンデン
サなどのときは直流を重畳して測定しなければな
らない場合があり、このようなときに第１図のま
までは直流を供給するのが困難である。(c) Problems with the prior art In Fig. 1, the two-winding transformer 3 is connected to both ends of the signal source 1, which has the advantage of being able to cancel out the common mode noise superimposed on the signal source 1. be. However, when the circuit element 4 is an electrolytic capacitor or the like, it may be necessary to superimpose direct current for measurement, and in such a case, it is difficult to supply direct current as shown in FIG.

(d) 考案の目的この考案は、第１図の二本巻トランス３の接続
を変更して、直流を重畳することができる回路を
提供することを目的とする。(d) Purpose of the invention The purpose of this invention is to provide a circuit that can superimpose direct current by changing the connection of the two-wound transformer 3 shown in Figure 1.

(e) 考案の実施例この考案による実施例の回路を第２図に示す。
第２図の９は抵抗、１０は直流供給端子、１１は
直流電源、１２はバイパスコンデンサであり、他
の部分は第１図と同じである。(e) Example of implementation of the invention A circuit of an example of this invention is shown in Fig. 2.
In FIG. 2, 9 is a resistor, 10 is a DC supply terminal, 11 is a DC power supply, 12 is a bypass capacitor, and the other parts are the same as in FIG.

第２図の二本巻トランス３では、端子３１を信
号源１に接続し、端子３２を測定回路側のアース
点に接続する。そして、端子３３を抵抗９から直
流供給端子１０に接続し、端子３４を測定回路に
接続する。すなわち、第２図では、端子３１に加
えた信号源１の信号を二本巻トランス３の相互イ
ンダクタンスにより導通のない端子３４に伝え
る。 In the two-wound transformer 3 shown in FIG. 2, the terminal 31 is connected to the signal source 1, and the terminal 32 is connected to the ground point on the measuring circuit side. Then, the terminal 33 is connected from the resistor 9 to the DC supply terminal 10, and the terminal 34 is connected to the measuring circuit. That is, in FIG. 2, the signal from the signal source 1 applied to the terminal 31 is transmitted to the non-conducting terminal 34 by the mutual inductance of the two-wound transformer 3.

第１図の場合と同じ理由で、バイパスコンデン
サ１２を信号源１のアース点に接続し、端子３２
を測定回路のアース点に分けて接続する。 For the same reason as in Figure 1, bypass capacitor 12 is connected to the ground point of signal source 1, and terminal 32
Separately connect it to the ground point of the measurement circuit.

抵抗９の抵抗値は第１図の抵抗２と同じように
二本巻トランス３の特性インピーダンスと等しく
する。その理由は、第１図の場合と同じである。
第２図では、抵抗９を端子３３と直流供給端子１
０の間に接続しているが、第１図の抵抗２のよう
に端子３１と信号源１の間に接続してもよい。 The resistance value of the resistor 9 is made equal to the characteristic impedance of the two-wound transformer 3, similar to the resistor 2 in FIG. The reason is the same as in the case of FIG.
In FIG. 2, resistor 9 is connected to terminal 33 and DC supply terminal 1.
0, but it may be connected between the terminal 31 and the signal source 1 like the resistor 2 in FIG.

回路素子４に直流を重畳させるときは、第２図
のように直流供給端子１０に直流電源１１を接続
する。回路素子４に直流を重畳させないときは、
直流供給端子１０を信号源１のアース点に接続す
る。直流供給端子１０を信号源１のアース点に接
続した場合の第２図は、第１図と同じように動作
する。 When direct current is superimposed on the circuit element 4, a direct current power supply 11 is connected to the direct current supply terminal 10 as shown in FIG. When direct current is not superimposed on circuit element 4,
The DC supply terminal 10 is connected to the ground point of the signal source 1. The operation shown in FIG. 2 when the DC supply terminal 10 is connected to the ground point of the signal source 1 is the same as that shown in FIG. 1.

(f) 考案の効果この考案によれば、二本巻トランスを用いた測
定信号供給回路に容易に直流を重畳させたり、直
流を重畳させないようにしたりすることができ
る。(f) Effects of the invention According to this invention, direct current can be easily superimposed on a measurement signal supply circuit using a two-winding transformer, and direct current can be prevented from being superimposed.

[Brief explanation of the drawing]

第１図は従来回路の一例を示す図、第２図はこ
の考案による実施例の回路図。１……信号源、２……抵抗、３……二本巻トラ
ンス、４……測定される回路素子、５……増幅回
路、６……基準抵抗、７……電圧端子、８……電
流端子、９……抵抗、１０……直流供給端子、１
１……直流電源、１２……バイパスコンデンサ。 FIG. 1 is a diagram showing an example of a conventional circuit, and FIG. 2 is a circuit diagram of an embodiment according to this invention. DESCRIPTION OF SYMBOLS 1...Signal source, 2...Resistance, 3...Two-winding transformer, 4...Circuit element to be measured, 5...Amplification circuit, 6...Reference resistance, 7...Voltage terminal, 8...Current Terminal, 9...Resistance, 10...DC supply terminal, 1
1...DC power supply, 12...Bypass capacitor.

Claims

[Claims for Utility Model Registration] A signal source 1, a two-winding transformer 3 in which terminals 31 and 32 are electrically connected, and terminals 33 and 34 are electrically conducting, and a resistance value equal to the characteristic impedance of the two-winding transformer 3. It is equipped with a resistor 9 and a DC supply terminal 10, which connects the signal source 1 and the terminal 31 and connects the terminal 3.
2 to the ground point of the measurement circuit, connect DC supply terminal 10 and terminal 33, and connect terminal 34 to the measurement circuit, and connect resistor 9 between signal source 1 and terminal 31 or between DC supply terminal 10 and terminal 33. When superimposing DC on the circuit element, connect the DC power supply to the DC supply terminal 10, and when not superimposing DC on the circuit element, connect the DC supply terminal 10 to the ground point of the signal source 1. A measurement signal supply circuit for a circuit element measuring instrument characterized by: