Keyboard for powering on or off computer

1. Technical Field

The present disclosure relates to keyboards, and particularly to a keyboard which can power a computer on or off.

2. Description of Related Art

A contemporary keyboard as an input device has very simple functions. The design of the keyboard often focuses on improving keys of the keyboard rather than more uses of the keyboard.

FIG. 1 is a schematic, isometric view of an exemplary embodiment of a keyboard and a computer, the keyboard including an input circuit, a control circuit, a switch circuit, and a detection circuit.

FIG. 2 is a circuit diagram of the input circuit of FIG. 1 .

FIG. 3 is a circuit diagram of the control circuit, the switch circuit, and the detection circuit of FIG. 1 .

Referring to FIGS. 1 to 3 , an exemplary embodiment of a keyboard 10 includes a housing 30 , a switch 50 arranged on the housing 30 , and an input circuit 100 , a control circuit 200 , a switch circuit 300 , and a detection circuit 400 arranged in the housing 30 . The switch 50 includes four trigger terminals 510 , 520 , 530 , and 540 .

The input circuit 100 , the switch circuit 300 , and the detection circuit 400 are all connected to the control circuit 200 . The four trigger terminals 510 , 520 , 530 , and 540 of the switch 50 are connected to the input circuit 100 . In one embodiment, the switch 50 may be a touch switch, a push-type switch, or another kind of switch. The input circuit 100 receives power on or power off operations. The control circuit 200 actuates the switch circuit 300 , to power on and power off a computer 28 accordingly.

The input circuit 100 includes a control chip U 1 , five capacitors C 1 -C 5 , and four pull-up resistors RP 1 -RP 4 . The control chip U 1 includes four input terminals I 0 -I 3 , two power supply terminals AHL and VD, four output terminals O 1 -O 4 , and two ground terminals G 1 and G 2 . The four input terminals I 0 -I 3 are connected to the trigger terminals 510 , 520 , 530 , and 540 of the switch 50 , and are also grounded via the capacitors C 1 -C 4 , respectively. The power supply terminals AHL and VD are connected to a power supply VCC, and are also grounded via the capacitor C 5 . The output terminals O 1 -O 4 are connected to the control circuit 200 , and are also connected to the power supply VCC via the pull-up resistors RP 1 -RP 4 , respectively. The ground terminals G 1 and G 2 are grounded. In this embodiment, the power supply VCC is a 5 volts (V) power supply. A type of the control chip U 1 is Tch04A. In other embodiments, the capacitors C 1 -C 5 can be omitted, and the control chip U 1 can be other types of control chips.

The control circuit 200 includes a crystal oscillator X, a microcontroller P 1 , three resistors R 1 -R 3 , four capacitors C 6 -C 9 , a battery B 1 , and a diode D 1 . The microcontroller P 1 includes two oscillator terminals OCS 1 and OCS 2 , two power supply terminals V 1 and VD 1 , five input terminals RC 1 -RC 5 , four output terminals RB 1 -RB 4 , and two ground terminals G 3 and G 4 . The crystal oscillator X is connected between the two oscillator terminals OCS 1 and OCS 2 . The two oscillator terminals OCS 1 and OCS 2 are also grounded via the capacitors C 8 and C 9 , respectively. The power supply terminal VD 1 is connected to the power supply VCC. The power supply terminal V 1 is connected to the power supply VCC via the resistor R 3 , and is also grounded via the capacitor C 7 . The capacitor C 6 is connected between the power supply VCC and ground. A cathode of the diode D 1 is connected to the power supply VCC. An anode of the diode D 1 is connected to an anode of the battery B 1 , and is also grounded via the resistors R 1 and R 2 that are connected in series. A cathode of the battery B 1 is grounded. A node between the resistors R 1 and R 2 is connected to the input terminal RC 5 of the microcontroller P 1 . The input terminals RC 1 -RC 4 of the microcontroller P 1 are connected to the output terminals O 1 -O 4 of the control chip U 1 , respectively. The output terminals RB 1 -RB 3 are connected to the detection circuit 400 . The output terminal RB 4 is connected to the switch circuit 300 . The ground terminals G 3 and G 4 are grounded. In this embodiment, the battery B 1 is a 6V power supply, a type of the microcontroller P 1 is PRC16F72. In other embodiments, the battery B 1 can be another type of power supply, and the microcontroller P 1 can be another type of microcontroller.

The switch circuit 300 includes a transistor Q 1 and two resistors R 4 and R 5 . A base of the transistor Q 1 is connected to the output terminal RB 4 of the microcontroller P 1 via the resistor R 4 . An emitter of the transistor Q 1 is grounded. A collector of the transistor Q 1 is connected to the power supply VCC via the resistor R 5 , and is also connected to a control terminal PWR of a motherboard 26 of the computer 28 , for powering on or off the computer 28 . For example, a keyboard cable 20 of the keyboard 10 can be connected to an idle pin of a keyboard socket 22 of the motherboard 26 , and the idle pin of the keyboard socket 22 is connected to the control terminal PWR of the motherboard 26 . In this embodiment, the transistor Q 1 functions as an electronic switch is an npn transistor. In other embodiments, the transistor Q 1 can be other types of electronic switches, such as an N-channel metal oxide semiconductor field effect transistor (NMOSFET).

The detection circuit 400 includes a transistor Q 2 , a diode D 2 , a buzzer Z 1 , two light emitting diodes (LEDs) LE 1 and LE 2 , and three resistors R 6 -R 8 . A base of the transistor Q 2 is connected to the output terminal RB 1 of the microcontroller P 1 via the resistor R 6 . An emitter of the transistor Q 2 is grounded. A collector of the transistor Q 2 is connected to an anode of the diode D 2 . A cathode of the diode D 2 is connected to the power supply VCC. The buzzer Z 1 is connected between the anode and the cathode of the diode D 2 . Cathodes of the LEDs LE 1 and LE 2 are connected to the output terminals RB 2 and RB 3 of the microcontroller P 1 , respectively. Anodes of the LEDs LE 1 and LE 2 are connected to the power supply VCC via the resistors R 7 and R 8 respectively. In this embodiment, the transistor Q 2 functions as an electronic switch is an npn transistor. In other embodiments, the transistor Q 2 can be another type of electronic switch, such as an NMOSFET, and the detection circuit 400 can be omitted as needed.

The following depicts how the keyboard 10 powers on and powers off the computer 28 . When the control terminal PWR of the motherboard 26 receives a low level voltage (e.g., 0V) and a current state of the computer 28 is in a powered on state, the computer 28 will be powered off. When the control terminal PWR receives a low level voltage (e.g., 0V) and the current state of the computer 28 is in a powered off state, then the computer 28 will be powered on. When the control terminal PWR receives a high level voltage (e.g., 3V), the computer 28 will remain in the current state.

When the computer 28 needs to be powered on or off, the switch 50 is actuated, that is, at least two of the trigger terminals 510 , 520 , 530 , and 540 of the switch 50 are triggered. At least two of the input terminals I 0 -I 3 of the control chip U 1 receive trigger signals from the trigger terminals of the trigger terminals 510 , 520 , 530 , and 540 correspondingly. At least two of the output terminals O 1 -O 4 of the control chip U 1 output control signals to the corresponding input terminals of the input terminals RC 1 -RC 4 of the microcontroller P 1 . For example, if two trigger terminals 510 and 520 of the switch 50 send trigger signals to the input terminals I 0 and I 1 of the control chip U 1 , the corresponding output terminals O 1 and O 2 of the control chip U 1 output control signals to the input terminals RC 1 and RC 2 of the microcontroller P 1 . When at least two of the input terminals RC 1 -RC 4 of the microcontroller P 1 receive the control signals, the output terminal RB 4 of the microcontroller P 1 is at a high level, such as 3V, the transistor Q 1 is turned on to pull the control terminal PWR to a low level, such as 0V, therefore, the computer 28 is powered on. After the computer 28 is powered on, the output terminal RB 2 of the microcontroller P 1 outputs a low level voltage, such as 0V, the LED LE 1 may emit green light to indicate that the computer 28 is powered on. As the power supply VCC, facilitates as a system power supply of the computer 28 , provides power during the computer 28 is in the powered on state, the diode D 1 is turned off, and the battery B 1 does not provide power to the microcontroller P 1 , thereby saving electricity of the battery B 1 .

The keyboard 10 can also detect electricity of the battery B 1 . When the battery B 1 is at a low level, such as 5.7V, a voltage of the node between the resistors R 1 and R 2 drops below a certain value, such as 5V, the microcontroller P 1 detects a voltage at the input terminal RC 5 is less than a certain value, such as 5V. The output terminal RB 1 of the microcontroller P 1 is at a high level, such as 3V, the transistor Q 2 is turned on. The anode of the diode D 2 is at a low level, such as 0V, the diode D 2 is turned off, and the buzzer Z 1 outputs a sound. The output terminal RB 3 of the microcontroller P 1 is at a low level, such as 0V, the LED LE 2 may emit red light. In other embodiments, the output terminal RB 1 of the microcontroller P 1 can output a pulse signal in when the battery B 1 is at a low level, such as 5.7V, as a result the buzzer Z 1 can output a short sound repeatedly to indicate that the battery B 1 needs to be replaced.

The keyboard 10 can also prevent the switch 50 from actuating inadvertently by operational errors. When the switch 50 is accidentally actuated, that is, only one of the trigger terminals 510 , 520 , 530 and 540 of the switch 50 is trigged to send a trigger signal to one of the input terminals I 0 -I 3 of the control chip U 1 . One of the output terminals O 1 -O 4 of the control chip U 1 outputs a corresponding control signal to one of the input terminals RC 1 -RC 4 of the microcontroller P 1 . For example, the trigger input terminal 510 of the switch 50 outputs a trigger signal to the input terminal 10 of the control chip U 1 . The output terminal O 1 of the control chip U 1 outputs a corresponding control signal to the input terminal RC 1 of the microcontroller P 1 . The output terminal RB 3 of the microcontroller P 1 is at a low level (e.g., 0V), and the LED LE 2 emits red light.

It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structure and function of the embodiments, the disclosure is illustrative only, and changes may be made in details, especially in matters of shape, size, and arrangement of parts within the principles of the embodiments to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.