DigitalElectronicsU1L2555Timer

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Multiple Choice
Identify the choice that best completes the statement or answers the question.

For the 555 Timer oscillator circuit shown below, calculate the period. Use the formulas from lecture.

a.	0.0151s	c.
b.	0.0101s	d.	15093.54s

For the 555 Timer oscillator circuit shown below, calculate the frequency. Use the formulas from lecture. (hint: You already calculated the period for this circuit in another problem.)

a.	60Hz	c.	66mHz
b.	66.2HZ	d.	10mHz

For the 555 Timer oscillator circuit shown below, calculate the duty cycle. Use the formulas from lecture.

a.	50%	c.	67%
b.	10%	d.	33%

Problem

Use Multisim to create and simulate the 555 Timer oscillator circuit. Use the oscilloscope’s markers to make the necessary measurements. Determine the frequency and duty cycle of the output signal. They should be similar to what you calculated in a previous problem. Your circuit should look exactly like this.

      Use your T1 and T2 markers to find the Period and Frequency. They should be similar to the problem that you already completed. You will use this circuit to do calculations in another problem.

You have already created the circuit below for the 555 timer. Complete the table below in an excel spreadsheet or word table. Use the oscilliscope to aid you in completing the table. When you are done with the table, answer the 3 questions at the bottom on your document and email me your completed assignment.

Complete the table by varying the values of RA, RB and C as given on the left hand side of the table.

RA	RB	C	Period(T)	Frequency(f)	t_H	t_L	Duty Cycle
100 W	330 W	22 mf
330 W	330 W	22 mf
560 W	330 W	22 mf
330 W	100 W	22 mf
330 W	330 W	22 mf
330 W	560 W	22 mf
330 W	330 W	10 mf
330 W	330 W	22 mf
330 W	330 W	47 mf

What effect did varying the RA have on the frequency and duty cycle?

What effect did varying the RB have on the frequency and duty cycle?

What effect did varying the C have on the frequency and duty cycle?