Traditional Chinese Practical Human body reaction speed tester: Circuit Design, Parts List & Workshop Prototype Guide

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Human body reaction speed testerThe principle circuit diagram of the human body reaction speed tester is shown in Figure 2.IC3 and IC4 are CMOS decimal counting/timing decoders. They have a clock input terminal CL and an allowable input terminal EN. R is the clear terminal, as well as ten output terminals Q0~Q9 and a carry terminal C0. The output status of the ten output terminals Q0~Q9 corresponds to the number of input pulses, and they are all active at high level. When the input signal is introduced from the EN terminal, CL must be "1", and the counter transmits information under the action of the lower edge of the input pulse. When CL = "0", the input pulse does not work; when the input signal is introduced from the CL terminal, EN must be "0", and the counter transmits information under the action of the upper edge of the input pulse. When EN = "1", the input pulse does not work. Adopt rising edge trigger effective method. IC1 is a clock generator composed of 555 time base circuit, and its output pulses are sent to the input terminals of gate 4 and counter C1872 respectively. IC2 is a four-2-input NAND gate C036 circuit.When the tester presses SB1-1, because SB1-2 is turned on, the R terminal of C1871 is cleared because it obtains a high level, and the light-emitting tube LED0 lights up, indicating that it can be turned on. SB1-1 is also turned on, the output of gate 1 is "1" and the output of gate 2 is "0", the CL terminal of C1872 is also "1", the counter C1872 starts counting and its output Q0~3 are high level in sequence, but at this time because the transistor VT1 is cut off, LED10-13 does not emit light, and C1871 stops counting because the output of gate 2 is "0" and gate 4 is blocked. At this time, the subject can press SB2. It can be seen from the figure that since SB2 is turned on, the output of gate 2 is "1", gate 4 is opened, C1871 counts with the number of input pulses, and LED1-9 lights up one by one. C1872 stops counting because the output of gate 1 is "0" and the CL terminal is also "0". At the same time, the transistor VT1 is saturated and turned on, and its LED10-13 is at high level because one of the output terminals of counter C1872 is high, and the corresponding LED lights up. Let LED11 light up at this time. When the subject presses the luminous button switch SB4 immediately when LED11 lights up (button switch SB3-6 and LED10-13 are assembled separately), the zero-level clamping effect of gate 3 and diode VD1 causes the output of gate 1 to be "1" and the output of gate 2 to be "0". C1871 stops counting due to the blockade of gate 4. From the number of lit LEDs 1-9, the subject's reaction time can be calculated. If the signal period of input gate 4 is set to 30ms, if the subject sees LED11 light up after pressing SB2 and then quickly presses the luminous button SB4. If LED6 lights up at this time, its reaction time is 6×30=180ms. If you are a beginner, you can choose 100ms as the time interval for LED0~LED9 to move one bit, and you only need to adjust RP. bordercolor="#FFD1BB" bordercolorlight="#FFFFFF"> …

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