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 , E7 C! a0 W+ [' N0 R

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

-

Generality " E# c; @1 s8 U# Q3 D

- \& Z6 T% B% q, qTo 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
  Q3 a% A& ?# a* EThe maximum voltage drop which should not be exceeded, when passing from noload
to load condition, is 5% of the rated voltage.
- Voltage ripple value
The supply voltage ripple, at no-load condition, should not exceed 5%.
NOTES:
$ c. d6 j  c% Y( L3 a- 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.
  B0 X) [/ I1 u# M, T6 G0 a7 n9 \- The use of a three-phase rectifying bridge, which gives a theoretical ripple of about 4,2%, complies with this recommendation.
- Recovery voltage
. ~6 x5 H) y. L; i+ r+ J. STest circuit, where:
- E is the supply voltage at no-load condition;
: |; B0 [( a8 Z( _. Y- Li is equivalent to the different self-inductances of the supply as well as the stray inductances of the rest of the test circuit;
3 e: h5 x( ]0 }- Cp is the stray capacitance of the circuit;
2 D' U- h2 V7 k- Rp is the parallel damping resistance.
- m2 ^! f% z! h8 e+ WNeglecting the parallel damping resistor, Rp, the parameters Li and Cp should be adjusted so as to obtain:
- Li = 2·10-3 H ± 25%, and
- Cp = 50 mF ± 25%.
; B/ ^: S" I8 Z. e/ T: L% oNOTE - Adopting the above mentioned parameters, all CTL Laboratories will get approximately
- the same time constant T = Li / Ri = 2·10-3 / Ri;
- the same oscillatory frequency fo = 1 / 2· (Li Cp)1/2  500 Hz.
1 e! K( @5 F' j$ k
. ?2 g2 n+ H' V. \


1 n8 k/ H2 y% f9 B8 |* ~. Y1 ~