Tools

To design astable multivibrator using 555 timer IC.

  1. Click on the Components button to place components on the table.

             

Fig. 1 Components

  1. Make connections as per the circuit diagram and pin diagram of ICs or according to connection table

Note :- Connect,

  a. 1st leg of potentiometer to + 5 V power supply.
  b. 2nd leg of potentiometer to pin 7 of IC.
  c. 3rd leg of potentiometer to ground.

Fig. 2 Circuit diagram of an astable multivibrator

Fig. 3 Pin diagram of 555 Timer IC

Table 1: Connection table

  1. Connect the C.R.O on output terminal of circuit.
  2. Click on Check Connections button. If connections are right, click on ‘OK’, then Simulation will become active.
  3. Set R1 = 5 KΩ by using potentiometer knob.
  4. Connect CH1/CH2 of C.R.O. to output terminal of the circuit.
  5. Observe output wave on C.R.O by adjusting C.R.O channel CH1/CH2 and TIME knobs.
  6. Use X Shift and Y Shift buttons for wave shifting.
  7. Measure the frequency of output wave at C.R.O.
  8. Fill the observation table by required values.
  9. Repeat steps 5, 6, 7, 8 and 9 for the different values of R1 = 10 KΩ, 15 KΩ and 20 KΩ.
  10. Compare both experimental and theoretical frequencies.
  11. Click on the Reset button to reset the page.