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 ! O( o2 a0 B/ H# Q" ^ % ^9 Q/ J. B4 z- Y; J

Characteristics of D.C. electric circuits for verifying normal operation and making and breaking cap ... 5 w. ~" ?9 F) h8 H4 ]+ [

- 4 O4 V7 D% |9 W8 n0 u

Generality

8 _1 I0 S. _$ j2 g" kTo 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
" K& w6 l$ B/ {: _The maximum voltage drop which should not be exceeded, when passing from noload
7 O7 q: r7 B2 s# a+ ?0 a2 yto load condition, is 5% of the rated voltage.
- Voltage ripple value
The supply voltage ripple, at no-load condition, should not exceed 5%.
5 j9 A6 {" J: f* N: z4 @NOTES:
- u/ [/ S* x9 F$ a, U3 n( 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.
- The use of a three-phase rectifying bridge, which gives a theoretical ripple of about 4,2%, complies with this recommendation.
( ~% i& ^- l  L1 k2 n- Recovery voltage
Test circuit, where:
- 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;
! C3 Y; P/ J! J6 b) y5 L- Cp is the stray capacitance of the circuit;
8 a+ Y; v- o7 j& l- Rp is the parallel damping resistance.
Neglecting the parallel damping resistor, Rp, the parameters Li and Cp should be adjusted so as to obtain:
) u. }4 W* i6 F( G' k* P# K- Li = 2·10-3 H ± 25%, and
# O9 ?2 e$ [% w* f% D# H# D- Cp = 50 mF ± 25%.
1 V- b$ {. O. K- n8 ]! ]4 C4 cNOTE - Adopting the above mentioned parameters, all CTL Laboratories will get approximately
- the same time constant T = Li / Ri = 2·10-3 / Ri;
5 h9 K+ d; X5 [" o0 y; W2 Z( A- the same oscillatory frequency fo = 1 / 2· (Li Cp)1/2  500 Hz.
) y, c& {8 ]0 J
# M) E& \$ J: M" \  N9 @  N9 J

! X  Q) j9 t# u; j1 s: `' w
. ]/ i1 g6 K- O* ?