You can generate 50Hz or 60Hz using this frequency generator. This oscillator can be used as the front end of circuits that require precision pulses.
A crystal is used in the circuit to generate clock pulses. The circuit uses two counter ICs CD4060 and 7490 to divide the basic frequency to generate 50Hz or 60Hz pulses.
PARTS LIST | |
R1 | 2.2MΩ |
C1 | 24pF |
C2 | 24pF |
C3 | 0.01µF |
C4 | 47µF 16V |
C5 | 0.1µF |
C6 | 100µF 16V |
XTAL | 4.096MHz or 4.9152MHz Crystal |
IC1 | CD4060 |
IC2 | 7490 (SN74LS90N) |
IC3 | 7805 Regulator |
“X” is a test point. |
CD4060 act as an oscillator and frequency divider here this is arranged to divide by 8192Hz which gives 600hz when you using 4.9152MHz crystal or 500hz when you using 4.096MHz crystal. That frequency further divided by 10 using 7490 IC is to obtain 50Hz or 60Hz output.
4.096MHz Crystal
4.096MHz=4096Khz=4096000Hz
4096000/8192=500Hz
500/10=50Hz
4.9152MHz Crystal
4.9152MHz=4915.2KHz=4915200Hz
4915200/8192=600Hz
600/10=60Hz
You can check CD4060 crystal oscillator and frequency divider work correctly via “X” test point. when you use 4.096MHz crystal “X” point gives 500Mhz output and 4.9152MHz crystal gives 600Hz output. If you don’t need a test point you can ignore it.