Description: Hardware circuit can be divided into signal conversion circuit, frequency divider circuit, the data selection circuit, single-chip systems, and display circuit of five parts.
Level-shifting circuit:
The need for level-shifting circuit: as in the MCU can only count on the pulse count, but the actual need to measure the frequency of the signal is varied, a pulse wave, there may be sine, triangle, etc. so they need a circuit to test the signal pulse can be counted.
By the level conversion circuit to form a sinusoidal input signal with frequency fx entire square wave fo, convert square wave to sine wave signal can be used to achieve zero comparator circuit. Sinusoidal signal with the zero level by LM833N comparison, the voltage output of LM833N greater than zero when the positive power supply 5V, output voltage is less than zero, the negative power supply 0V.
To Search:
File list (Check if you may need any files):
pinglvji
........\keil 源码
........\.........\1
........\.........\1.hex
........\.........\1.M51
........\.........\1.Opt
........\.........\1.plg
........\.........\1.Uv2
........\.........\f.c
........\.........\f.LST
........\.........\f.OBJ
........\.........\lcd.c
........\.........\lcd.h
........\proteus仿真
........\...........\频率计.DSN
........\...........\频率计.PWI
........\使用前必读.txt
........\所用元件资料
........\............\74151数据选择器.pdf
........\............\74HC4017.pdf
........\............\LM833N.pdf
........\论文设计核心思想
........\................\论文核心思想.doc
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