Abstract: A fan delay controlling apparatus includes a connector connected to a fan of an electronic device, a power supplying module connected to the connector, and a power controlling module connected to the power supplying module. The power supplying module is connected to a fan power source and a stand-by power source. The power controlling module controls the power supplying module supply power to the fan when the electronic device including the fan powers off until an ambient temperature is lower than a predetermined value.

Abstract: An exemplary surge current alarm circuit includes a detecting circuit to detect a surge current and convert the surge current into a digital signal with a pulse width corresponding to a duration of an over value part of the surge current when the surge current is over a limitative current value; a processing circuit connected to the detecting circuit to receive the digital signal and generate an alarm signal when the pulse width of the digital signal is over a limitative time; and an alarm circuit connected to the processing circuit to give an alarm upon receiving the alarm signal from the processing circuit.

Abstract: A programmable logic device (PLD) data transfer cable includes a parallel interface, a programming interface, and a logic control circuit. The parallel interface is used for connecting to PLDs. The logic control circuit includes a first group of transmission channels, a second group of transmission channels, a first group of switches, and a second group of switches. The first and second group of switches control the working status of the first and second group of transmission channels respectively. The electrical connections between pins of the parallel interface and the programming interface when first group of transmission channels are activated are different with those when second group of transmission channels are activated.

Abstract: A circuit for indicating operating status of a plurality of hardware devices of a computer includes a detecting module, a decoding module, and an indicating module. The indicating module includes a dual color indicator and two electronic switches connected to a first input and a second input of the dual color indicator respectively. The detecting module detects an operating status of the plurality of hardware devices, and outputs state signals of each hardware device during power on self test of the computer. The decoding module decodes the state signals, and outputs level control signals to turn on or off the two electronic switches. The dual color indicator indicates operating status of the plurality of hardware devices by shifted to be at different indicating states by the two electronic switches correspondingly.

Abstract: A switch-mode power supply for selectively providing power from a main power source and a standby power source to an electronic device is provided. The switch-mode power supply includes a signal input, a first transistor, a second transistor, a driving circuit, and a switching circuit. The signal input is used for receiving a control signal. The driving circuit and switching circuit connect the signal input to the gate of the second transistor in series. When the driving circuit detects the first transistor is switched off, the gate of the second transistor is immediately pulled up to open the second transistor, and when the driving circuit detects the first transistor is switched on, the gate of the second transistor is immediately pulled down to close the second transistor.

Abstract: A programmable logic device (PLD) data transfer cable includes a parallel interface, a programming interface, and a logic control circuit. The parallel interface is used for connecting to PLDs. The logic control circuit includes a first group of transmission channels, a second group of transmission channels, a first group of switches, and a second group of switches. The first and second group of switches control the working status of the first and second group of transmission channels respectively. The electrical connections between pins of the parallel interface and the programming interface when first group of transmission channels are activated are different with those when second group of transmission channels are activated.

Abstract: An exemplary motherboard tester includes a processor comprising a pair of data terminals for transmitting data; and an interface comprising: a pair of data terminals coupled to the data terminals of the processor respectively; at least one output terminal arranged for connecting to a corresponding pin of a chipset mounted on a motherboard to send a test signal generated by the processor to the pin; and at least one input terminal arranged for connecting to a test point on the motherboard which is electrically connected to the pin, to receive a feedback signal from the test point, wherein, the processor compares the feedback signal with the test signal to determine whether the pin of the chipset is normal, open, or shorted.

Abstract: An exemplary surge current alarm circuit includes a detecting circuit to detect a surge current and convert the surge current into a digital signal with a pulse width corresponding to a duration of an over value part of the surge current when the surge current is over a limitative current value; a processing circuit connected to the detecting circuit to receive the digital signal and generate an alarm signal when the pulse width of the digital signal is over a limitative time; and an alarm circuit connected to the processing circuit to give an alarm upon receiving the alarm signal from the processing circuit.

Abstract: An exemplary monitoring device includes: a time chip connected to a connector to generate a time signal and a count signal when the connector is working, the time signal indicating how long the connector is in use, the count signal indicating that the total number of times the connector has been used should be incremented by one; a processor connected to the time chip to receive the time signal and count signal, and generate a data signal including a total service time and a total number of times the connector has been used; a clock generator connected to the processor to provide a clock signal; and an output port connected to the processor to output the data signal. The monitoring device keeps a watch on a connector for showing the service information about the connector to make an operator know if the connector needs to be replaced.

Abstract: A drying apparatus includes a humidity sensor module, a micro control unit (MCU) module, an indicator circuit, and a fan module. The humidity sensor module measures relative humidity of air in a computer, and converts that measurement to an electronic signal. The MCU module receives the electronic signal from the humidity sensor module, and respectively outputs an indication signal and a control signal when the measured humidity is greater than a predetermined value stored in the MCU module. The indicator circuit indicates the humidity in the computer is too high when it receives the indication signal from the MCU module. The fan is activated when it receives the control signal from the MCU module.

Abstract: A switch-mode power supply for selectively providing power from a main power source and a standby power source to an electronic device is provided. The switch-mode power supply includes a signal input, a first transistor, a second transistor, a driving circuit, and a switching circuit. The signal input is used for receiving a control signal. The driving circuit and switching circuit connect the signal input to the gate of the second transistor in series. When the driving circuit detects the first transistor is switched off, the gate of the second transistor is immediately pulled up to open the second transistor, and when the driving circuit detects the first transistor is switched on, the gate of the second transistor is immediately pulled down to close the second transistor.

Abstract: A cable use tracking apparatus includes a switch module fixed to a cable, a detecting module, and a computer communicating with the detecting module. The switch module switches from a first state to a second state based on activity of the cable relative to an electronic device. The detecting module detects the switching of the states, and outputs result indicating signals. The computer counts and displays the number of times that the cable is used based on the indicating signals.

Abstract: An exemplary state monitoring circuit includes a data transform unit, a counter, and a clock generator. The data transform unit is connected to a system management bus (SMBUS) to obtain serial signals output from the SMBUS, and convert the serial signals to parallel signals. The counter is connected to a south bridge chip of the system and the data transform unit, for counting parallel signals converted by the data transform unit, if the count is finished, the counter sends a reset signal to the south bridge chip. The clock generator is connected to the counter for providing a clock frequency signal to the counter.

Abstract: An exemplary keyboard includes a first keyboard unit having a container defined in a side thereof, and a second keyboard unit pivotally attached to the first keyboard unit. The second keyboard includes a handle to drive the second keyboard unit to rotate between a first position in which the second keyboard unit is accommodated in the container of the first keyboard unit, and a second position in which the second keyboard unit is outside the first keyboard unit.

Abstract: A computer security system includes a motherboard, a power supply, and a lock. The power supply supplies power to the motherboard via a power supply circuit. The lock includes a key, and the lock is electrically connected between the motherboard and the power supply. The key controls open and closed states of the power supply circuit.

Abstract: A video signal circuit of a notebook computer includes a north bridge chipset, a control module, a VGA port, an A/D converter, a selection module, and a control unit. The north bridge chipset is coupled to the control module and the selection module. The VGA port is coupled between the control module and a display device and a processing device. The A/D converter is coupled between the control module and the selection module. The selection module is coupled to an LCD of the notebook computer. The control unit is coupled to the selection module and the control module. The video signal circuit can be controlled to send a first analog and digital video signals generated by the north bridge chipset to the displaying device and the LCD respectively, or receive a second analog video signal from the processing device and display it on the LCD.

Abstract: An exemplary state monitoring circuit includes a data transform unit, a counter, and a clock generator. The data transform unit is connected to a system management bus (SMBUS) to obtain serial signals output from the SMBUS, and convert the serial signals to parallel signals. The counter is connected to a south bridge chip of the system and the data transform unit, for counting parallel signals converted by the data transform unit, if the count is finished, the counter sends a reset signal to the south bridge chip. The clock generator is connected to the counter for providing a clock frequency signal to the counter.

Abstract: A computer system includes a power supply, a mainboard, and a restart control circuit. The power supply includes a system power source output and a stand-by power source output. The restart control circuit has a first input connected to the system power source output, a second input connected to the stand-by power source output, and an output connected to the mainboard. During an interval of time after the computer system is turned on, the system power source output provides working voltage for the restart control circuit, and the output provides trigger signals at a high level for the mainboard. During an interval of time after the computer system is turned off, the stand-by power source output provides stand-by voltage to the restart control circuit, and the output provides trigger signals at a low level for the mainboard to trigger the computer system to restart.