Overview and parameters of switching power supply box
The switch stabilized power supply box is one of the auxiliary units of the combined instrument of the electric unit. It adopts advanced energy distribution and conversion technology to centralize the new 24V DC stabilized power supply for each unit instrument.
Overview of switching power supply box
The box is one of the auxiliary units of the combination instrument of the electric unit. It is a new 24V DC regulated power supply that centrally supplies power to each unit instrument, and adopts advanced energy distribution and conversion technology. details as follows:
Wide input AC range, high efficiency, light weight, digital display, stable output, safe and reliable operation, no annoying power frequency noise of old-fashioned linear power supplies. With output overvoltage, undervoltage, overcurrent, short circuit full guarantee function. Once a failure occurs, the voltage output will be automatically stopped and an alarm will be issued, and the backup power supply will be automatically connected to ensure the normal power supply of the entire system. It adopts the internationally popular European-style terminal block with no maintenance, strong locking, convenient operation and high electrical safety performance, and is equipped with multiple sets of DC24V outputs. It has the function of guaranteeing the external power supply. When the power box fails, it can automatically cut off the external power supply, and there is no voltage output to ensure the instrument system. And there is an external contact point of ALARMOUT for sound and light alarm.
Parameters of switching power supply box
AC input voltage: AC90～270V47HZ～60HZ (1A) (numerous display)
AC120～270V47HZ～60HZ (3A) (digital display)
AC130～270V47HZ～60HZ (5A) (digital display)
AC170～265V47HZ～60HZ (10A) (digital display)
DC output voltage: DC24V±0.5V
DC output current: 1A, 3A, 5A, 10A
Output ripple: 10~100mVp-p
Efficiency: ≧85%
Load regulation: 10% to 100%, ≦0.5% to 1.5%
Dielectric strength:
Input/output 1500V/1 minute
Input terminal/chassis 1500V/1 minute
Output terminal/chassis 1500V/1 minute
Leakage current≦10mA
Insulation resistance≧30MΩ
MTBF:≧50000 hours (average working time between failures)
Working environment temperature: -10℃～+50℃
Principle of switching power supply box
The switching stabilized power supply box is composed of five basic modules. The AC input line is rectified and filtered by one module, and the high-frequency converter will step down and output it, and the other module will further rectify and filter the output. The accuracy of the output voltage is completed by the control circuit, which returns the output to the converter to form a closed loop. When the load changes or the input voltage fluctuation causes the output voltage to change, the control loop sensitively detects the slight change of the output voltage, and automatically sends a corresponding signal to the converter. The pulse feedback adjusts the signal to keep the output voltage at the original state, thereby stabilizing the voltage output.
For some reason, when the output voltage exceeds 26V or is lower than 22V, the protection system starts the relay immediately, connects the backup power supply and sends out an alarm light prompt. When the load (working instrument) fails and forms a short circuit, the protection system will automatically close the output to avoid major accidents.
The use of switching power supply box
1. Input
Voltage: The input voltage specification must be consistent with the range marked on the switching power supply box.
Power factor: The power factor of general switching power supply is 0.6, and the switching regulated power supply with AF active filter can reach 0.99, so it should be paid attention to when wiring.
Grounding: Since the switching power supply has an EMI filter, the grounding terminal of the power supply shell must be connected to the earth with a thick and short wire.
It is especially important when using multiple units to ensure safe use.
2. Output
Output power: It should be within the rated range, and attention should also be paid to the relationship between ambient temperature and output derating.
3. Lifespan
The life of switching power supply is divided into three stages.
Initial failure stage: In order to prevent initial failure, bad components have been screened out before installation. Before leaving the factory, it has undergone a full-load 72-hour aging test. Therefore, most of the products have entered the stage of occasional failure when they are delivered to customers.
Occasional failure stage: the stability of each failure is related to its mean time between failures (MTBF), basically the failure rate is extremely low. However, the failure rate in the occasional failure stage is related to the user's installation and working conditions (ambient temperature, derating, ventilation, vibration).
Wearout failure stage: After the sporadic failure period, the power supply enters the wearout failure stage.
Ambient temperature and life: Since the switching power supply works under high frequency and high power conditions, the life of many devices is closely related to temperature, such as electrolytic capacitors, fans, etc. The relationship between the life of the electrolytic capacitor and the ambient temperature is: if the ambient temperature increases by 10°C, the life will be halved; on the contrary, if the ambient temperature is reduced by 10°C, the life will be doubled.
