DSH 201A Characteristics of D.C. electric circuits for verifying normal operatio

小米

广东安规检测
有限公司提供：

小型摆管淋雨试验机

IPX5X6X7喷水试验机

1000L恒温恒湿箱

各种试验指现货

可程式恒温恒湿试验箱

水平垂直燃烧机

自动卷线器试验机

耐划痕试验机

各种灯头量规现货

灼热丝试验机现货

GB1002插头量规

IPX1-X7淋雨现货

IEC61347/UL935镇流器热试验箱

灯具防风罩

IK冲击试验机

UL498插头插座量规

VDE0620插头插座量规

稳定性试验台

家电温升测试角

针焰试验机现货

热电偶焊机现货

家电125mm试验指

E12灯头量规

无绳壶无绳电熨斗插拔寿命试验机

IEC60335试验指甲

DSH 201A - }; S3 j. d: g% X! R - b, n6 x( i/ C; ?" h+ H% a) K7 N7 S

Characteristics of D.C. electric circuits for verifying normal operation and making and breaking cap ...

- ) b+ @0 ]0 [# Q1 r: J: r

Generality , }- O7 s/ K. N; M! ]3 V

4 u1 k. g$ o' B: }6 jTo reach an acceptable test reproducibility, when verifying normal operation and making and breaking capacity, it is recommended that the test circuit has the following characteristics:
- Voltage drop
! x& ]- d+ H0 B5 L9 ?7 bThe maximum voltage drop which should not be exceeded, when passing from noload
to load condition, is 5% of the rated voltage.
- Voltage ripple value
. N; O3 |( X, G  D9 O/ dThe supply voltage ripple, at no-load condition, should not exceed 5%.
NOTES:
* t% \; K3 a' P1 r5 q( D$ z- Percentage ripple is given by r% = Vac/Vdc x 100, where Vac is the RMS value of the superimposed a.c. voltage and Vdc is the d.c. voltage.
A simple way to evaluate the ripple is to use an oscilloscope, whose input is selected in a.c. for the measurement of Vac and in d.c. for the measurement of VDU.
- The limitation of the ripple, which occurs, in practise, in rectifying converters, may be obtained choosing appropriately a rectifying bridge.
- The use of a three-phase rectifying bridge, which gives a theoretical ripple of about 4,2%, complies with this recommendation.
. s7 }+ `% \5 x$ V- Recovery voltage
Test circuit, where:
  T4 U( ?$ t5 l! F; ~- E is the supply voltage at no-load condition;
- Li is equivalent to the different self-inductances of the supply as well as the stray inductances of the rest of the test circuit;
- Cp is the stray capacitance of the circuit;
- Rp is the parallel damping resistance.
Neglecting the parallel damping resistor, Rp, the parameters Li and Cp should be adjusted so as to obtain:
- Li = 2·10-3 H ± 25%, and
4 X# ]$ P# _. z: @3 c- Cp = 50 mF ± 25%.
NOTE - Adopting the above mentioned parameters, all CTL Laboratories will get approximately
2 b8 J  A2 ^8 h8 s; Z  D5 S- the same time constant T = Li / Ri = 2·10-3 / Ri;
, G0 o" T3 M2 y; ^( u- the same oscillatory frequency fo = 1 / 2· (Li Cp)1/2  500 Hz.
5 y9 F3 ^4 I# \% `. c7 m

1 N0 L& o- d' V


  r, s7 k* P- T: m