JPS63113967U

JPS63113967U -

Info

Publication number: JPS63113967U
Application number: JP367487U
Authority: JP
Priority date: 1987-01-16
Filing date: 1987-01-16
Publication date: 1988-07-22

Description

[Brief explanation of the drawing]

第１図はこの考案の一実施例による測定装置の
入力回路を示す回路図、第２図，第３図，第５図
および第６図はそれぞれの測定対象を測定するた
めの第１〜第４の切換回路の状態を示す回路図、
第４図は第３図における第１の切換回路の部分を
示す等価回路図、第７図は従来の測定装置の入力
回路を示す回路図、第８図は第７図のスイツチを
オンさせたときの等価回路図である。図において、２１，２２，２３は第１，第２お
よび第３の入力端子、２４は第１の切換回路、２
５，２６，２７，３５，３６，４３は第１，第２
，第３，第４，第５および第６のスイツチ、２９
，３７は第１，第２の増幅回路、３４は定電流源
、４１は抵抗、４２は感温抵抗素子を示す。 FIG. 1 is a circuit diagram showing the input circuit of a measuring device according to an embodiment of this invention, and FIGS. A circuit diagram showing the state of the switching circuit No. 4,
Figure 4 is an equivalent circuit diagram showing the first switching circuit in Figure 3, Figure 7 is a circuit diagram showing the input circuit of a conventional measuring device, and Figure 8 is a circuit diagram showing the input circuit of a conventional measuring device. FIG. In the figure, 21, 22, 23 are first, second and third input terminals, 24 is a first switching circuit, 2
5, 26, 27, 35, 36, 43 are the first and second
, third, fourth, fifth and sixth switches, 29
, 37 are first and second amplifier circuits, 34 is a constant current source, 41 is a resistor, and 42 is a temperature-sensitive resistance element.

Claims

[Scope of utility model registration request]

1st, 2nd, and 3rd to which voltage, current, resistance such as three-wire resistance temperature detector, and electromotive force of thermocouple etc. are inputted.
a second switch connected in parallel with a first switch connected in series to the first input terminal;
a first switching circuit, a first amplifier circuit, which has one end of a resistor for converting current to voltage connected to the connection point of the third switch; the first input terminal; and the first switching circuit. a second switching circuit for connecting and disconnecting a constant current source, one end of which is connected to the connection point;
a third switching circuit and a second amplifier circuit that are connected in series to the third input terminal; and a thermoelectric circuit that has one end connected to a connection point between the third switching circuit and the second amplifier circuit. Equal cold junction compensation voltage
and a fourth switching circuit for supplying the amplifier circuit to the input circuit of the measuring device.