High quality adjustable step-down buck converters.
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DC 8-35V to DC 3-15V Buck Converter, DC18V20V24V to DC 12V 3A Step Down Converter Waterproof Voltage Regulator Power Supply Buck
Aliexpress UK
DC 5V - 45V. The external heat sink can withstand high current operation. which is commonly used for AC and DC input.
eBay
DC 8-35V to DC 3-15V Buck Converter DC18V20V24V to DC 12V 3A Step Down Converter Waterproof Voltage Regulator Power Supply Buck
Aliexpress UK
If the output current greater than 2A, or output power greater than 10W, then a heatsink should be fitted and forced air flow from a fan should be considered. Model: LM2596S DC-DC buck module. Output current: 3A or 10 Watts (maximum).
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3A Mini Buck Board Converter 5V-30V To 3.3V/5V/12V Fixed Output Power Supply DC-DC Step Down Module Buck Converter Board
Aliexpress UK
Output Current: 3A ( maximum ). ( maximum 92% ) maximum output current is 3A. 10x LM2596 DC-DC Step Down Power Module. OUT + output positive OUT - output negative. IN + input positive IN - input negative.
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6/10Pcs MP1584EN Step-Down Power Module DC-DC 3A Adjustable Buck LM2596 Ultra-Ultra-Small Size
Aliexpress UK
Brand Unbranded MPN Does Not Apply .
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DC-DC Buck Step Down Module LM2596 DC/DC 4.0~40V to 1.25-37V Adjustable Voltage Regulator With LED Voltmeter
Aliexpress UK
When the right “OUT” led light, it shows output, the left “IN” led show input. 3 、 Output current:2A. 6 、 Built in output short protection function. 5 、 Input reverse polarity protection. How to adjust the accuracy?.
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DC-DC 3A Buck Step-down Power Supply Module MP1584EN 5V-12V 24V to 5V 3.3V 9V 12V Fixed Output for Arduino Replace LM2596 Green
Aliexpress UK
(Features: all use high quality solid state capacitors, 36u thicker circuit board, high Q value high power inductor with output LED indicator. No boosting). 4.01uF high-frequency bypass capacitor, effectively filter out high-frequency noise.
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DC-DC 3A Buck Step-down Power Supply Module MP1584EN 5V-12V 24V to 5V 3.3V 9V 12V Fixed Output for Arduino Replace LM2596
Aliexpress UK
Module highlights Module performance and characteristics.
eBay
DC-DC Buck Step Down Module LM2596 DC/DC 4.0~40V to 1.25-37V Adjustable Voltage Regulator With LED Voltmeter
Aliexpress UK