RX7/N4A Decade Capacitance Box
Purpose
The RX7/N4A capacitor box is a precision rotary ten step capacitor box. It can work in DC or ACcircuits as a variable impedance of AC bridges, components of filtering circuits, and other circuitsthat require capacitance to vary over a large range. It is suitable for working conditions withairtemperature ranging from +10 ℃ to +35 ℃ and relative humidity ranging from30%to 80%.
Structure
A decade capacitor box is composed of a combination of different numbers of decade switchcomponents, with each decade switch component consisting of several capacitors of differentcapacities in parallel to form 1 to 10 steps. The capacitor used is of high quality, and the switchisa silver copper composite contact point with good contact performance. The capacitors used in this capacitor box mainly have a loss positive pitch angle value<15 ×10-4 polystyrene or polypropylene film capacitors. The entire electrical part of the capacitor boxis installed in a shielded chassis. The outgoing end of the capacitor box is on the panel, and theterminals marked with "1" and "2" output the capacitance value. The terminal marked with "0" isa shielding dedicated outgoing end, which should be grounded together with the detectioninstrument or related circuit during testing or use.
Technical characteristics
1. Specification:
Maximum capacity 111.1110 μ F ≈ 10-4F, N4 within the model represents an index of minus4;
The minimum step level is 100pF=10-10F, where NA within the model represents an exponent ofminus 10, and A is a hexadecimal value of 10;
Knobs 6;
Variable range 0~111.1110 uF;
Accuracy:10×10uF Group ±0.5%,
10×1uF Group ±0.5%,
10×0.1uF Group±0.5%,
10×0.01uF Group±0.65%,
10×0.001uF Group±2%,
10×0.0001uF Group±5%,
When calculating according to the above formula, the following conditions should be observed:
(1) Surrounding temperature+20 ℃± 5 ℃, The relative humidity is between 30% and 80%.
(2) Verification frequency: less than 1uF1000Hz, greater than 1uF100H z
(3) Working voltage: 50V (effective value)
(4) The starting capacitance of the capacitor box should be subtracted from the measurementresults.
3. When the ambient temperature changes from+20 ℃ to+35 ℃ or+10 ℃, the change incapacitance should not exceed 1/2 of the error.
4. The tangent value of the dielectric loss angle shall not exceed:
10×10uF Group：2.5×10-3
10×1uF Group：2.5×10-3
10×0.1uF Group：2.5×10-3
10×0.01uF Group：3×10-3
10×0.001uF Group：1×10-2
10×0.0001uF Group：5×10-2;
5. DC withstand voltage: 250V
6. Starting capacitance:Starting capacitance ≤ 100pF;
7. Overall dimensions and weight:Dimensions: 550×200×150mm3 Weight: