R.S.F. Engineering - switching power supply production and processing test specification

The first part: the power index, definition of concept
A description of the input voltage output voltage. Effects of several indexes.
1 absolute voltage regulation coefficient.
A. The absolute voltage regulation coefficient : that the load is constant, regulated power supply DC output variation of delta U0 and delta Ui input power variation ratio. Both:
K = Delta U0 / delta Ui.
B. The relative voltage regulation coefficient : that the load is constant, the regulator output DC voltage Uo relative variation of Uo and output power of Ui relative variation ratio of Ui. Urgent:
S = Uo / Uo / Ui / Ui
2 grid adjustment rate.
It represents the input voltage from rated value change + - 10%, regulated power supply output voltage relative variation, sometimes also with absolute value representation.
The 3 voltage stability.
Rated load current keep within the scope of any value, the input voltage within a predetermined range caused by the variation of output voltage of Uo / Uo relative change ( percentile ), known as the regulator voltage stability.
Two. Load on the output voltage effects of several indexes.
1 load regulation rate ( also called current regulation ).
At rated voltage, the load current is varied from zero to maximum output voltage, maximum relative variation, commonly expressed as a percentage, sometimes with absolute change quantity.
The 2 output resistance ( also known as equivalent impedance or resistance).
At rated voltage, the load current changes of IL caused by change of the output voltage of Uo, then the output resistance
Ro = | Delta Uo / delta IL | europe.
Three indexes of several forms of ripple voltage.
1 the maximum ripple voltage.
Rated output voltage and load current, the output voltage ripple ( including noise) of the absolute value of the size, usually with a peak-to-peak or RMS said.
The 2 ripple coefficient Y ( % ).
At rated load current, output ripple voltage effective value Urms and output DC voltage ratio of Uo, both
Y = Umrs / Uo x100%
The 3 voltage ripple suppression ratio.
In terms of the ripple frequency ( e.g. 50HZ ), the output voltage ripple voltage Ui ~ and the output voltage ripple voltage Uo ~ than, i.e.:
The ripple suppression ratio = Ui ~ / Uo ~.
A statement here: unlike ripple noise. Ripple is in between output terminals of an input frequency and switching frequency synchronization composition, peak to peak ( peak to peak ) value, generally in the output voltage is below 0.5%; noise appears at the output terminals of the ripple outside of a high frequency component, peak to peak ( peak to peak ) value, generally in the output voltage of about 1%. Ripple and noise is the two synthesis, peak to peak ( peak to peak ) value, generally in the output voltage is below 2%.
Impact of current four. Impulse current refers to the input voltage at predetermined intervals to connect or disconnect, the input current reaches a steady state before the maximum instantaneous current. The general is 20A -- 30A.
Overcurrent protection in five. Is a kind of power supply load protection function, in order to avoid including the output terminal short circuit, overload output current of the power source and the load damage. Over current setpoint is generally rated current of 110% -- 130%.
Overvoltage protection six. Is a kind of terminal over voltage of load protection function. General provisions for the output voltage of the 130% -- 150%.
Seven. Output undervoltage protection. When the output voltage in the standard value is below the detection output voltage drop, or for the protection of the load and prevent error operation to stop power supply and an alarm signal, for the output voltage of the 80% -- 30%.
Overheat protection eight. In the internal power supply is abnormal or due to the improper use of the power supply temperature or exceed the standard stop power supply work and send out alarm signals.
Temperature drift and temperature coefficient of nine.
Temperature drift: the change of environment temperature affect the components of the parameter changes, thereby causing the regulator output voltage change. Commonly used temperature coefficient temperature drift size.
Positive temperature coefficient: 1 degrees C temperature changes caused by the output voltage variation of UoT, unit is V / C or millivolts per degree celsius.
Relative temperature coefficient temperature 1 degrees C: output voltage relative to changes caused by UoT / Uo, the unit is V / c..
Ten drift.
Regulator in input voltage, load current and environmental temperature to maintain a certain case, element parameters and stability also can cause the change of the output voltage, slow change called drift, rapid change is called noise, is situated between two between call ups.
Said drift in two ways:
1 in a specified period of time the value of the output voltage change Delta Uot.
2 at the designated time output voltage relative to changes of Uot / Uo.
Investigation of the drift time can be set at 1 minutes, 10 minutes, 1 hour, 8 hours or longer.
Only in the high precision voltage regulator, have temperature coefficient and temperature drift of two indexes.
Response time eleven.
Refers to the sudden changes in load current, voltage regulator output voltage from a began to change the arrival of new stable value for a period of time to adjust.
In the DC voltage regulator, is used in the rectangular wave load current waveform of the output voltage to said this feature, called excessive characteristics.
Distortion of twelve.
This is the AC voltage regulator characteristic. Refers to the output waveform is not a wave, waveform distortion, called distortion.
Noise thirteen. According to 30HZ -- 18kHZ audible frequency regulation, the switching power supply switching frequency is not a problem, but for the fan of the power supply according to the needs to be provided.
Fourteen input noise. In order to make the switch power supply work to maintain normal state, according to the rated input conditions, according to the allowable input and overlapped on the industrial frequency pulse voltage ( 0 -- peak ) formulation of input noise index. General and a pulse width of 100 -- 800us, voltage 1000V.
Surge fifteen. This is the input voltage, with more than 1 minutes intervals in accordance with the provisions of plus the number of a surge voltage, in order to avoid destruction of insulation flashover, arc, abnormal phenomenon. Communications equipment and other specified values for thousands of volts, for general 1200V.
Electrostatic noise in sixteen. At rated input conditions applied to the power supply, any part of the frame body, the output circuit can maintain the normal working state of a repetitive pulse shaped electrostatic. General guarantee 5 -- less than 10KV.
The stability of seventeen.
Allows the use of conditions, the output voltage maximum relative changes of Uo / Uo.
Eighteen. Electrical safety requirements ( GB 4943-90 ).
1 power structure - Safety requirements.
1) space requirements. UL, CSA, VDE security specification on the charged part and between the charged part and the charged metal part between the surface, space distance. UL, CSA requirements: the voltage between electrodes is greater than or equal to 250VAC high voltage between the conductors, and the high-voltage conductor and non-live metal part ( not included here between the wire ), either at the surface or in the space, should be 0.1 inches; VDE AC line between 3mm creep or 2mm net voids; IEC requirement: communication lines between 3mm net space and in the AC line and the ground conductor between the 4mm net space. In addition, VDE, IEC requirements in power between the output and the input of at least 8mm, spatial distance.
2) the dielectric test method ( called hypertension: input and output, input and input AC, two grade ).
3) leakage current measurement. Leakage current is flowing through the input side grounding current in a switching power supply, mainly by the noise filter bypass capacitor leakage current. UL, CSA are exposed live metal parts should be connected with the ground, leakage current measurement is achieved by these parts and the earth is connected between a 1.5K ohm resistor, the leakage current should not be greater than 5 ma. VDE allows: 1.5K ohm resistor and capacitor is connected with 150nP. And 1.06 times of the rated voltage is applied, the data processing equipment, the leakage current shall not exceed 3.5 ma. Is generally around 1 ma.
4) insulation resistance test. VDE requirements: input and the low voltage output circuit shall be 7M ohm resistor, the contacts to the metal part and the input, due 2M ohm resistor or 500V DC voltage for 1 minutes.
5) printed circuit board requirements. Requirements of UL certification 94V-2 material or better than that of the material.
2 pair of power transformer structure safety requirements.
1) transformer insulation. The windings of the transformer should be to use copper wire enameled wire, and other metal parts shall be coated with a ceramic, paint and other insulating material.
2) the dielectric strength of transformer. In the experiments should not appear the breakdown of the insulating layer and arcing phenomena.
3) transformer insulation resistance. Transformer winding insulation resistance between at least 10M in Europe, in the winding and core, frame, shielding layer is applied between the 500 volt DC voltage, duration 1 minutes, there should not be a breakdown, arcing phenomena.
4) the humidity resistance of transformer. Transformer must be placed in moist environment, once the insulation resistance and the dielectric strength test, and meet the requirements. Humid environment is generally: the relative humidity is 92% ( tolerance 2% ), temperature at 20 to 30 degrees Celsius, the permitted error 1%, need, placing at least 48 hours later, immediately above the experimental. The transformer temperature itself should not more into moist environment prior to testing high of 4 degrees celsius.
5) VDE on transformer temperature characteristics and requirements.
6) UL, CSA on transformer temperature characteristics and requirements.
Note: IEC -- International Electrotechnical Commission
VDE -- Verbandes Deutcher Electrotechnicer
UL -- Underwriters ' Laboratories
CSA -- Canadian Standards Association
FCC -- Federal Communications Commission
Radio disturbance ( nineteen. According to GB 9254-1998 test ).
The 1 power terminal disturbance voltage limits.
The 2 radiation disturbance limits.
Twenty environment experiment.
Environmental test is product or material is exposed to natural or artificial environment, so they may actually encountered in storage, transportation and use conditions of the performance evaluation.
The low temperature
The high temperature
The constant damp heat
The alternating hot and humid
The collision ( shock and bump )
The vibration.
Constant acceleration.
The storage
The mold
From corrosive atmosphere (e.g. salt spray )
Of sand and dust
Will air pressure ( high or low pressure )
The temperature change.
Not flammable
All sealed
There water
Development of radiation ( solar or nuclear )
For soldering
The terminal strength
Noise: micro 65DB came
Electromagnetic compatibility test twenty-one.
Electromagnetic compatibility test ( electromagnetic compatiblity EMC )
Electromagnetic compatibility refers to a device or system in the common electromagnetic environment can work normally without the environment in any things intolerable electromagnetic interference.
Electromagnetic interference wave in general there are two routes of transmission, according to the various pathways were evaluated. One is to wave long band to power line communication, to launch area to interfere with the way, generally below 30MHZ. This wavelength frequency in the attached to electronic equipment power line within the length of less than 1 the wavelength of the radiation to space, the output is very small, which can grasp occurs to the power supply line voltage, which can be assessed adequately interference size, this noise is called conduction noise.
When the frequency is above 30MHZ, will also be shorter wavelength. Now if only to occur in the power line noise source voltage is evaluated, and the actual interference with. Therefore, using the determination by direct spread to the space of the interference wave noise size evaluation method, the noise is the radiation noise. Determination of radiation noise method with the electric field strength on the propagation of spatial interference wave direct determination method and determination of leaking to the power line power method.
Electromagnetic compatibility test includes the following test:
The magnetic field sensitivity: ( immunity ) device, subsystem or system exposed to electromagnetic radiation of undesired response degree. Sensitivity level is smaller, more sensitive, immunity worse. Fixed frequency, peak magnetic field
The electrostatic discharge sensitivity: having different electrostatic potential objects close to each other or to directly contact caused by charge transfer. 300PF for charging the capacitor to the 15000V, through a 500 ohm resistance discharge. Super bad, but after normal. Data transfer, storage, can not be lost
The power transient sensitivity: including the peak signal sensitivity ( 0.5us 10us 2 times ), the voltage transient sensitivity ( 10%-30%, 30S recovery ), frequency transient sensitivity ( 5%-10%, 30S recovery ).
The radiation sensitivity of equipment caused by: degraded radiation interference field measurement. ( 14K-1GHZ, field strength for 1V / M )
The conduction sensitivity: when the equipment caused by undesired response or cause the performance degradation, in power, control or signal line interference signal or voltage measurement. ( 30HZ-50KHZ 3V, 50K-400M 1V )
The non operating magnetic field interference: packaging box 4.6m flux density is less than 0.525uT, 0.9m 0.525Ut.
The operating magnetic field interference: upper and lower, left, right alternating magnetic flux density is less than 0.5mT.
And propagates along the conductor conduction interference: interference. 1