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    12V DC 25A 300W Switching Power Supply

    5 out of 5 based on 2 reviews | Write a review
    Low price 300W switching power supply converts universal AC to 12V DC at rated current of 25A. Quality SMPS power supply has built-in DC fan for cooling and short circuit, overload and overvoltage protections, ideal for all kinds of electrical equipment or devices.
    SKU: ATO-SMPS-300-12
    30-day Returns
    Free Shipping
    Delivery date: 6-12 days


    • Univeral AC input/Full range
    • Protections: short circuit, overload and overvoltage
    • Forced air cooling by built-in DC fan
    • PWM control and regulated
    • 100% full load burn-in test
    • Low cost, compact size and high efficiency


    DC Voltage12V
    Rated Current25A
    Current Range0 ~ 25A
    Rated Power300W
    Ripple & Noise (Max.)(Note 2)150mVp-p
    Voltage Adjust Range10 ~ 13.2V
    Voltage Tolerance (Note 3)±1.0%
    Line Regulation±0.5%
    Load Regulation±0.5%
    Setup, Rise, Holdup Time200ms, 50ms, 20ms at full load
    InputVoltage Range90 ~ 132VAC/180V~264VAC (selected by a switch) or 254 ~ 370VDC
    Frequency Range47~63Hz
    Efficiency (Typ.)74%
    AC Current (Typ.)6.5A/115V AC 4A/230V AC
    Inrush Current (Typ.)Cold start: 50A/230V AC
    Leakage Current<3.5mA/240V AC
    ProtectionOverload105~135% rated output power
    Protection type: Constant current limiting, recovers automatically after fault condition is removed.
    Protection type: Hiccup mode, recovers automatically after fault condition is removed.
     Over temperatureRTH3 ≥65°C FAN ON, ≤55°C FAN OFF, ≥80°C output shut down.
    EnvironmentWorking Temperature-10 ~ +50℃
    Working Humidity20~90% RH non-condensing
    Storage Temperature-20~+85℃
    Storage Humidity10~95% RH non-condensing
    Temperature Coefficient±0.03%/℃ (0~50℃)
    Vibration10 ~ 500Hz, 2G 10min./1 cycle, period for 60min. each along X, Y, Z axes
    Safety & EMCWithstand VoltageI/P-O/P: 1.5KVAC I/P-FG: 1.5KVAC O/P-FG: 0.5KVAC
    Isolation ResistanceI/P-O/P, I/P-FG, O/P-FG: 100M Ohms/500VDC/25℃/70% RH
    OthersMTBF≥234.3K hrs MIN. MIL-HDBK-217F (25℃)
    Dimension215*115*50mm (L*W*H)
    Note1. All parameters NOT specially mentioned are measured at 230V AC input, rated load and 25°C of ambient temperature.
    2. Ripple & noise are measured at 20MHz of bandwidth by using a 12" twisted pair-wire terminated with a 0.1uf & 47uf parallel capacitor.
    3. Tolerance includes set up tolerance, line regulation and load regulation.

    Dimension (Unit: mm)

    300W switched mode power supply dimensionSMPS power supply terminal pin number assignment


    12V DC Switching Power Supply Details

    SMPS Power Supply Applications

    • Power Tools
      Electric Saw, Drilling Machine, Ginder, Sand Blast Machine, Puching Machine, Weeding Machine, Air Compressor, etc.
    • Offices Devices
      Computer, Printer, LCD Monitor, Scanning Machine, etc.
    • Electrics & Household Appliance
      TV, VCRS, Radio, Dust Collector, Fan Lamp or LED Strip, Sewing Machine, Microwave Oven, Fridge/Freezr, Coffemarker, etc.
    • Industrial Equipemnt
      Monitoring Equipment, Shipping, Vehicle, Metalhalide Lamp, Solar System, Wind Power Generation, etc.

    Tips: Advantages and disadvantages of switching power supply

    ♦ SMPS advantages

    1. Switching power supply is characterized by low energy consumption and high efficiency. In circuits of switching power supply, transistors excited by drive signals operates in alternating status from “on” to “off” or from “off” to “on”. Fast conversion speed and low energy consumption of switching transistors have greatly improved efficiency of power supply.

    2. SMPS power supply is characterized by small size and weight. The switching power supply is equipped with no transformer and cooling fins, so it presents smaller size and weight.

    3. Switching power supply excels in its regulation range. Input voltage of the SMPS is adjusted by occupation ratio of drive signals. Changes of input signal voltage can be compensated by frequency modulation or width adjustment. When industrial frequency power grid experiences great changes, the switching power supply can still maintain stable output of voltage.

    ♦ SMPS disadvantages

    1. Switching power supply keeps bothered with serious switching noises. In the switching power supply, power switches and transistors remain in working status. AC voltage and AC current generated by them exerts pulse noises and resonance noises on other components. If users fail to inhibit, eliminate or shield these noises, the operation of the equipment will be seriously influenced.

    2. SMPS power supply provides no isolation for transformer of industrial frequency. Therefore, the noise may be passed to power grid of industrial frequency, sending serious noise to connected electronic devices, equipment and household appliances. Switching power supply performs poorly in coping with electromagnetic noise, but modern shield technologies can compensate its disadvantage in this aspect.

    Existing reviews of 12V DC 25A 300W Switching Power Supply
    Bought three of 12v power supplies, and came in time.
    Bought three of 12v power supplies, and came in time. Nice cover and solid built. I tested them when I just received them, and they worked as advertised. So far, these power supplies are performing very stable with no problem. Well worth the money.
    From: Albert | Date: 09/03/2020
    Was this review helpful? Yes No (0/0)
    Nice power supply.
    This SMPS works as what is supposed to do. Nice power supply!
    From: Marcel | Date: 03/07/2018
    Was this review helpful? Yes No (0/0)
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