MK2B Heat Bed PCB Heatbed For 3D Printer RepRap MendelFeature:Support 12V, 24V power.Double-sided, the other side is no wiring, heating uniformity, smooth printing.Regardless of the positive and negative terminal, you can free wiring.Description:Dimensions: 214 x 214 mmLaminate FR4: 1.6+-0.15 mm2 layer, 35μm copperRed soldermask: Both sidesWhite silkscreen: Both sidesPower input: 12V and 24vCopper plated holesResistance between 1.0 and 1.2 ohmConnection:12V connection: One cable connected to one, another cable connected to a wire 2,3 in the same time.At this time the resistance value of the two lines is 1.0 ~ 1.2Ω, the actual power is 144W.      24V connection: One cable connection 2, another line connected to 3 (1 unconnected), the resistance value of the two lines is 4.0Ω, actual power is 24 * 24/4 = 144W.The new version of the circuit, whether connected 12V, or 24V, the power will stable at 144W.Test report:12V connection:Current is 9.8A, as the temperature increases, the current drops to 8.8A (physical tips: resistance becomes larger as the temperature rises)24V connection:The theoretical maximum current is less than 5ANote:The LED and resistor are soldered, good compatibility, support 12V, 24V power.If you use 24V, this time the current is very large, MOS tube heat seriously, it is easy burned because of the high temperature.In addition, also consider the adequacy of power supply, power up to 576W of power is very expensive, if power shortage may affect the normal operation of other equipment such as motor.Also note that because of the wire is not enough thick and cause burning hot and soft.Package included:1 x Heated Bed