Description:Oscillation mode: linear regulator for buck, the AC voltage output voltage is rectified and filtered after less than 3V.After such dual input 12V, the rectifier voltage regulator filter is above 12x1.414 = 16.968 V, the output voltage can 16.968-3V = 13.968VRecommendation: Input voltage (rectified voltage smoothed means that instead of an ALTERNATE voltage, AC input is rectified and filtered to 1.414 times, if the input voltage of 12V AC is rectified and filtered after 12X1.414=16.968V) at least higher than the output voltage is 3 V, but not too high, too much pressure will only increase the power consumption 317/337, the heat of chips, the output current can also be lower, for example, as the input voltage is rectified and filtered voltage is 12 V, output regulation to 5 V, the regulator so that the pressure drop is above the chip 12-5=7V, if the current timeis 0.5A, so the power regulator tube is 0.5x7=3.5W, the higher the power, the more severe the heat.circuit board FR-4 plate using military grade One sheet material, plate, and some stability tolerance parameters, a material behaved very difficult, which is of interest to a number of other relatively cheap price sheet. plate PCB parameter elements are printed directly, without reference to a circuit diagram of the for case can be soldered directly, very convenient. Note:1. The double-sided spinning, process cushion increase cushions of tin and tin spray, can bear repeatedly desoldering, is not easy to fall. (fold conditions down refers to non-human caused)2. Once less likely to buckle, poor plaque will change with for time and the environment resulting from bending.3. More stable and reliable impedance. Specifications:Input voltage: AC 5V double AC double 20 V(AC double input only)for DC output: 1.3-25 VCurrent: 1 APCB Board Size: 6.2x5.9cm/2.44x2.32"Quantity: 1 Set Note:Please allow 1-3mm error due to manual measurement. pls make sure you do not mind before you bidDue to the difference between different monitors, the picture may not reflect the actual color of the item. Thank youNo Retail Package Package Includes:1 Set x Power Adapter DIY Kit