Capacitor as timer circuit generator#

Variable Frequency Generator using IC 555Д«ut, the question must be coming to your mind that why we need to use the variable resistor at all? Why we donвЂ™t just use a fixed resistor R2 of an appropriate value ? In the following diagram a variable resistor or a potentiometer is used to change the frequency of the output. Adjusting Frequency with Variable Resistor. So here will be concerned here only about changing the value of R2 and C1 while keeping the R1 constant. To know more about it please see this article. * Note : The resistance R1 will change only the duty cycle of the waveform. The second method includes the use of a Variable Capacitor ( varicap). There are two ways to adjust the frequency of a standard 555 timer astable circuit.ДЇirst method is by changing the values of R1 and R2 (R2 in particular) or through a Variable Resistor ( potentiometer). And if the time period decreases then the output frequency will go up. Thus, if the time period increases, the output frequency will go down. And as we know the time period and the frequency are inversely proportional. We can change frequency of the circuit by changing the values of these components particularly R2 and C1*.ДЄny change in the values of these components will change the overall Time Period. 555 Timer Astable Multivibrator Circuit DiagramДЄs we know that the frequency of 555 astable multivibrator circuit is determined by three components R1, R2 and C1.

Capacitor as timer circuit