| 摘要 |
A keyboard includes a mainbody, a number of keys, an interface, a control circuit, a switch, and a light emitting diode (LED). The interface includes a first group of pins and a second group of pins. The first and second groups of pins are connected to a motherboard. One of the second group of pins receives a +5V_standby voltage or a +3.3V_standby voltage from the motherboard. The control circuit is set inside the mainbody and is connected to the keys and the first group of pins of the interface. One of the second group of pins of the interface is further connected to an anode of the LED through the switch, and a cathode of the LED is grounded. |
