Four measuring ranges portable potentiometer

Abstract

A four-range portable potentiometer with three measuring discs for DC voltage measurement. Its first stepping disc is composed of a measuring disc and an auxiliary disc, and the second stepping disc is composed of ten 100Ω ring resistance nets to form a measuring disc. , the auxiliary plate is composed of 10 5Ω resistors, the third plate is a double slide wire plate, the two measuring plates are connected with the measuring slide wires by wires, and are not switched by switches, so that there is no variation and thermoelectric potential in the measurement of the potentiometer Influence, there are four ranges, in the ×0.01 range, the minimum resolution reaches 0.1μV, and the replacement discs of the first and second step discs are omitted.

Description

technical field

[0001] The invention relates to an instrument for measuring DC voltage. Background technique

[0002] At present, for the potentiometer with three measuring discs, in the connection between the three measuring discs, the intermediate disc is generally switched by a switch, which will cause a change in contact resistance and limit the resolution. In order to overcome this problem, large brushes are generally used to increase the contact area, and silver-copper composite materials are used; Patent No. ZL200520101772.0 has announced a new method for solving the variation of switch contact resistance with a potentiometer with three measuring discs. The first and second stepping discs are composed of a measuring disc, a substituting disc and an auxiliary disc. The resistance values ​​on the measuring disc and the substituting disc are the same. Every time a resistance is added to the measuring disc, the substituting disc will reduce the same resistance. , since t...

Examples

Embodiment Construction

[0007] In the figure, measuring panel II has ten 100Ω end-to-end resistance rings between contacts 1 to 9. When measuring panel II is set to "5", there are five 100Ω resistors between the brush of measuring panel II and node B. It is connected in parallel with five 100Ω resistors, and the maximum resistance after parallel connection is 250Ω, so the 5 contacts are directly connected to the corresponding points on the resistance ring, and the resistance value between the other contacts of the measuring panel II and node B must be 250Ω; when measuring When panel II is set to "4" or "6", four 100Ω resistors and six 100Ω resistors are connected in parallel between the brush of measurement panel II and node B, and the resistance after parallel connection is 240Ω, so contacts 4 and 6 pass through The 10Ω resistor is connected to the corresponding point on the resistance ring; when the measuring panel II is set to "3" or "7", between the brush of the measuring panel II and the node B a...

technical field

[0001] The invention relates to an instrument for measuring DC voltage. Background technique

[0002] At present, for the potentiometer with three measuring discs, in the connection between the three measuring discs, the intermediate disc is generally switched by a switch, which will cause a change in contact resistance and limit the resolution. In order to overcome this problem, large brushes are generally used to increase the contact area, and silver-copper composite materials are used; Patent No. ZL200520101772.0 has announced a new method for solving the variation of switch contact resistance with a potentiometer with three measuring discs. The first and second stepping discs are composed of a measuring disc, a substituting disc and an auxiliary disc. The resistance values ​​on the measuring disc and the substituting disc are the same. Every time a resistance is added to the measuring disc, the substituting disc will reduce the same resistance. , since t...

Examples

Embodiment Construction

[0007] In the figure, measuring panel II has ten 100Ω end-to-end resistance rings between contacts 1 to 9. When measuring panel II is set to "5", there are five 100Ω resistors between the brush of measuring panel II and node B. It is connected in parallel with five 100Ω resistors, and the maximum resistance after parallel connection is 250Ω, so the 5 contacts are directly connected to the corresponding points on the resistance ring, and the resistance value between the other contacts of the measuring panel II and node B must be 250Ω; when measuring When panel II is set to "4" or "6", four 100Ω resistors and six 100Ω resistors are connected in parallel between the brush of measurement panel II and node B, and the resistance after parallel connection is 240Ω, so contacts 4 and 6 pass through The 10Ω resistor is connected to the corresponding point on the resistance ring; when the measuring panel II is set to "3" or "7", between the brush of the measuring panel II and the node B a...

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