Posts Tagged ‘frequency divider’

Attenuate variable radio frequency

This circuit can be designed to attenuate signal frequency. Customizable from 1 to 40 dB.If you want to use the band uhf, should be fitted within the frame shield, and C1 to C3 type feeds true.The line should be as short as possible, and the diode should be a kind of low capacity on high speed. The potentiometer can be installed separately, if desired, as well as R3 and Zener diode.

Frequency Divider by one transistor BC549

This circuit designs to upward for divide by the frequency of a signal input , give down left just the half then to export come to the way output. Because of the transistor Q1 (BC549) bias stay the condition not active it then active get especial while signal input be positive volt only. This circuit modifies from oscillator model colpitts , Tank Circuit that compose L1,C4 and C5 can fine about 16.5 kHz. When get a signal input 30-60kHz the circuit lock and oscillator Generator in 15-30kHz frequency detail other sections , please see in the circuit be lucky yes.

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Frequency Divider by 555 and 4040

U1 7555 is a CMOS version of 555 LM555 pdf datasheet.
The 555 here is in Astable Oscillator mode, C1 and C4 are decoupling capacitors 0.1uF value, ceramic disc.
The output is around 100kHz, If C3 is plastic or mica the frequency output will be stable with temperature. It is better to use a crystal oscillator.
The 555 output is fed to clock input of 4040, the output of 555 will be a square wave, on every high to low transition (falling edge or negative transition) the counter increments by one and the output is 12 bit binary.
If input frequency is F the final output at Q12 is F/4096. The period T = 1/F.
If you make the 555 run at 1Hz, C3 around 7uF, Then this circuit becomes a long duration timer, the Q12 period will be 4096 seconds or 68 minutes

Read More Source:http://schematics.blogspot.com/2004/11/frequency-divider.html
Thank you.

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