Patent ID: 7952420

Claim:
A counting apparatus, comprising: a sampling circuit comprising an interface to connect a computer, a first electric switch, and a second electric switch, wherein a first terminal of the first electric switch is connected to a power terminal of the interface via a first resistor, a second terminal of the first electric switch is connected to a power supply via a second resistor, a third terminal of the first electric switch is grounded, a first terminal of the second electric switch is connected to the second terminal of the first electric switch, a second terminal of the second electric switch is connected to the power supply via a third resistor, a third terminal of the second electric switch is grounded; and a counting and displaying circuit comprising a first counter and a first display tube, the first counter comprising an enable terminal, a latch terminal, a clock-up counting terminal, a clock-down counting terminal, and seven output terminals, the first display tube comprising seven input terminals, wherein the input terminals of the first display tube are connected to the output terminals of the first counter correspondingly, the clock-up counting terminal of the first counter is connected to the second terminal of the second electric switch, the clock-down counting terminal of the first counter is grounded via a fourth resistor, the enable terminal and latch terminal of the first counter are grounded.