CN104237637A - Measuring method of blocking resistance of wave trapper - Google Patents

Abstract

The invention discloses a measuring method of the blocking resistance of a wave trapper, and belongs to the field of electricity. The measuring method solves the problem that in the prior art, an expensive instrument is needed for measuring blocking resistance. According to the technical scheme, a voltmeter U12 is connected between the two ends of a blocking resistor R12, the output impedance of an oscillator is selected to be 0 omega, and the output level of the oscillator is selected to be 0 dB, a plurality of frequency points are tested in the wave blocking frequency range of the wave trapper, the voltmeter U12 tests the value of U1, the value of U2 and the value of U12 every time the frequency of the oscillator changes, and then the blocking resistance R is worked out according to the following formulas of (1) phi=180o-arccos[(U12<2>+ U2<2>-U1<2>) /2U12U2] and (2) R12=U12cosphi*R2/U2, wherein phi is the supplementary angle of the included angle formed by U2 and U12 in a vector triangle formed by U1, U2 and U12. The measuring method is mainly used for measuring and working out the blocking resistance of the wave trapper.

Description

The measuring method of trap blocked resistance value

Technical field

The present invention relates to trap, particularly a kind of measuring method of trap blocked resistance value.

Background technology

In traditional blocked resistance value measurement method, according to Fig. 1 wiring, 0 Ω is selected in oscillator output impedance, and output level is 0dB, and at the multiple Frequency point of wave arrestment frequency range build-in test of trap, oscillator often changes a secondary frequencies, and voltage table U is a test U just ₁, U ₂value, is then calculated as follows resistance value require in trap wave arrestment frequency range, resistance value is not less than 570 Ω.Due in conventional methods where, want rapid results, need instrumentation, but the price comparison of instrument is expensive.

Summary of the invention

The object that the present invention will reach just is to provide a kind of measuring method of trap blocked resistance value, does not need expensive instrumentation.

In order to achieve the above object, the present invention adopts following technical scheme: the measuring method of trap blocked resistance value, at blocked resistance R ₁₂two termination voltage table U ₁₂, 0 Ω is selected in oscillator output impedance, and output level is 0dB, and at the multiple Frequency point of wave arrestment frequency range build-in test of trap, oscillator often changes a secondary frequencies, voltage table U ₁₂a just test U ₁, U ₂, U ₁₂value, then according to following computing formula,

$R_{12}=\frac{U_{12}\cos \mathrm{\&Phi;}}{U_2}\&times;R_2---\left(2\right)$

Wherein Φ is U ₁, U ₂, U ₁₂u in the vector triangle of composition ₂with U ₁₂the supplementary angle of angle, calculates blocked resistance value R ₁₂, in the wave arrestment frequency range of trap, require that blocked resistance value is not less than 600 Ω.

Further, described voltage table U ₁₂for the valve voltmeter of high resistant.

After adopting technique scheme, tool of the present invention has the following advantages: do not need expensive instrumentation, only need to programme on computers, can accomplish to put things right once and for all, as long as input U ₁, U ₂, U ₁₂just can directly obtain blocked resistance value R ₁₂, and adapt to new demand, namely blocked resistance value is not less than 600 Ω.

Accompanying drawing explanation

Below in conjunction with accompanying drawing, the invention will be further described:

Fig. 1 is the metering circuit of traditional blocked resistance value;

Fig. 2 is the metering circuit of the blocked resistance value in the present invention;

Fig. 3 is U ₁, U ₂, U ₁₂the vector triangle of composition.

Embodiment

The invention provides the measuring method of trap blocked resistance value, as shown in Figure 2, at blocked resistance R ₁₂two termination voltage table U ₁₂, 0 Ω is selected in oscillator output impedance, and output level is 0dB, and at the multiple Frequency point of wave arrestment frequency range build-in test of trap, oscillator often changes a secondary frequencies, voltage table U ₁₂a just test U ₁, U ₂, U ₁₂value, then according to following computing formula,

$R_{12}=\frac{U_{12}\cos \mathrm{\&Phi;}}{U_2}\&times;R_2---\left(2\right)$

Wherein Φ is U ₁, U ₂, U ₁₂u in the vector triangle of composition ₂with U ₁₂the supplementary angle of angle, as shown in Figure 3, calculates blocked resistance value R ₁₂, in the wave arrestment frequency range of trap, require that blocked resistance value is not less than 600 Ω.

In above-described embodiment, voltage table U and U ₁₂all adopt the valve voltmeter of high resistant.

Except above preferred embodiment, the present invention also has other embodiment, and those skilled in the art can make various change and distortion according to the present invention, only otherwise depart from spirit of the present invention, all should belong to the scope defined in claims of the present invention.

Claims (2)

1. the measuring method of trap blocked resistance value, is characterized in that: at blocked resistance R ₁₂two termination voltage table U ₁₂, 0 Ω is selected in oscillator output impedance, and output level is 0dB, and at the multiple Frequency point of wave arrestment frequency range build-in test of trap, oscillator often changes a secondary frequencies, voltage table U ₁₂a just test U ₁, U ₂, U ₁₂value, then according to following computing formula,

Wherein Φ is U ₁, U ₂, U ₁₂u in the vector triangle of composition ₂with U ₁₂the supplementary angle of angle, calculates blocked resistance value R ₁₂, in the wave arrestment frequency range of trap, require that blocked resistance value is not less than 600 Ω.

2. the measuring method of trap blocked resistance value according to claim 1, is characterized in that: described voltage table U ₁₂for the valve voltmeter of high resistant.