Input voltage range:

Users can see that the input voltage range on the power supply is 85~265VAC while the actual use is 100~240VAC. In fact, during the safety certification, the so-called±10% test will be conducted (IEC60950 +6% ~ -10%), so the voltage range defined in the power supply specifications will not be a problem in use; and the power supply is marked to meet the safety specifications and ensure that the user can correctly input the power supply. The power supply is labeled to meet safety regulations and to ensure that the user can input power correctly.

Power Factor:

Power factor correction is to improve the ratio of effective power to apparent power at the input of the power supply. Generally, for models without PFC circuit, the power factor at the input end is only 0.4~0.6, while with active PFC circuit, it can reach 0.95 or more, and the relevant formula is as follows

Apparent power = input voltage × input current (VA)

Effective power = input voltage × input current × power factor (W)

From an environmental point of view: the electric power company's power plant must generate electrical energy greater than the apparent power in order for its generating units to be able to steadily supply the market demand for electrical energy, while the actual use of electrical energy is the effective power. If the power factor is 0.5, it means that the generator set sends out more than 2VA of electricity to safely supply the demand of 1W of electrical energy, and its energy operation efficiency is poor. On the contrary, if the power factor is improved to 0.95, the generator set of the power company can generate more than 1.06VA power to supply the demand of 1W of electricity without any problem, and the operational efficiency of energy is better.

Protection function:

Over voltage / over current / over load / over temperature protection refers to the power supply due to the input voltage, load, environment, cooling circuit or device failure and other changes in internal and external conditions that threaten the safety of the power supply, resulting in the power supply can not work properly, the relevant circuit functions of the power supply is activated and the protection action occurs.

Over voltage protection: A feature of the switching power supply circuit that protects the switching power supply and the load when an abnormally high voltage is present at the output.

Under voltage protection: When the supply voltage of the protected circuit is below a certain value, the protector cuts off the line; when the supply voltage returns to the normal range, the protector automatically switches on the circuit.

Over current protection: In the DC switching power supply circuit, in order to protect the regulator tube from being burned when the circuit is short-circuited and the current increases. The basic method is that when the output current exceeds a certain value, the regulator tube is in reverse bias state, thus cutting off and automatically cutting off the circuit current.

Short-circuit protection: In the event of a short circuit, the output current of the switching power supply is limited to a safe value to protect the switching power supply from damage.

Over-temperature protection: DC switching power supply in the switching regulator of high integration and lightweight small size, so that its power density per unit volume greatly improved, so if the internal components of the power supply device does not correspondingly improve the requirements of its operating environment temperature, it will certainly make the circuit performance deterioration, premature failure of components. Therefore, in the high-power DC switching power supply should be set up in the over-temperature protection circuit.

Protection (action) in the following ways.

1. Restart (Divided into automatic and manual. Disconnect the power supply and then turn it on again, the power supply is back to normal. )
2. Hiccup (intermittent output).
3. Fold back limiting (when the load is close to a short circuit, the output current can be linearly reduced to the normal value of the method).
4. Current limiting ( or constant current, can limit the output current does not increase infinitely due to overload or short circuit of the load. (Even if the load has a short-circuit condition will not lead to equipment downtime and power supply damage).
5. Downtime over current / over load / over voltage / over temperature fault, usually refers to the output current / power / (or input) voltage and heat sink temperature exceed the protection threshold of the power supply above the rated value when the dangerous state.

Inrush Current:

Switching power supply in the moment of input will appear a brief (1/2 ~ 1 power cycle, EX: 60Hz power 1/120 ~ 1/60 seconds) of high current (according to product design is about 20 ~ 60A, please refer to the product specifications), the product will return to normal current input after power on, each time the moment of power input power supply will appear, this is a normal phenomenon, and will not This is a normal phenomenon and will not cause damage to the power supply. However, it is not recommended to continuously power on/off the power supply. It should also be noted that if multiple power supplies are turned on at the same time, it may cause the protection switch of the system distribution to jump off.

Output voltage accuracy:

Output voltage accuracy refers to the difference between the actual output voltage and the rated output voltage, and this error is the superimposed value of line stability and load stability. Usually this parameter is at +/-1% line stability is the percentage of output voltage deviation from the rated voltage when the input voltage varies between the maximum and minimum values of the allowable range. Load stability is the percentage of output voltage deviation from the rated voltage when the output load current varies between the maximum and minimum values of the allowable range.

IP Rating-IPXY

Dustproof rating (denoted by X) Waterproof rating (denoted by Y)

IP64-IP66: Suitable for use in wet environments or outdoor locations where rain is present, please refer to the IP rating test document for actual installation restrictions.

IP67: Protected against short term water immersion but not long term immersion in water

Efficiency: The ratio of total output power to active input power expressed as a percentage. That is: efficiency = output power / input power * 100%.

Rated power: The maximum output power of the power supply (the product of voltage V and current A).

EMC: electromagnetic compatibility (EMC) is the ability of a device or system to operate in its electromagnetic environment in compliance with the requirements and does not produce intolerable electromagnetic interference to any equipment in its environment. EMC includes EMI (electromagnetic interference) and EMS (electromagnetic tolerance) two departments, the so-called EMI electromagnetic interference, for the switching power supply conduct or radiation of harmful energy. And EMS refers to the ability of the switching power supply to be unaffected by the surrounding electromagnetic environment during the execution of its proper function.

Ripple: As the DC stabilized power supply is generally formed by the AC power supply by rectification and voltage stabilization and other links, it is inevitable that the DC stabilized amount more or less with some AC components, this superimposed on the DC stabilized amount of AC component is called ripple.

Output ripple and noise: within the specified bandwidth, the amplitude of the switching power supply output AC voltage, usually expressed in millivolts of peak-to-peak or RMS value.

Total Harmonic Distortion: THD for short, is the additional harmonic component of the output signal (harmonics and its multiplier components) over the input signal when input with a signal source, usually expressed as a percentage. Generally speaking, the total harmonic distortion at the frequency of 1000Hz is the smallest, so many products are the distortion of the frequency as its indicator. Therefore, when testing the total harmonic distortion, it is issued 1000Hz sound to test, the smaller the value of this one, the better.

Overshoot and Undershoot): Overshoot is the first peak or valley value exceeds the set voltage - for the rising edge is the highest voltage and for the falling edge is the lowest voltage. Undershoot is the next valley or peak. Excessive overshoot can cause protection diodes to operate, leading to premature failure. Excessive down-shoot can cause false clock or data errors.

Operating ambient temperature: The temperature range over which a switching power supply can operate with reasonable electrical specifications and stability. Unless specified as such, do not assume that a switching power supply can output full power over the entire temperature range, nor that a switching power supply can maintain the same electrical specifications over the entire operating temperature range.

PWM: Pulse Width Modulation: A voltage regulation method used in switching power supplies that controls the output by varying only the width of the pulse sequence.