Project #1: Monostable Multivibrator
This is the first project out of the "clocks" book.
1. Momentarily bring pin 2 of the 555 low by touching it to ground. What does the output do?
It turns on momentarily.
2. After the LED goes off, do this again and time the LED to see how long it remains on. About five second.
3. Use this formula to calculate how long the LED should stay on: t = R1 x C1 Does this agree with the time the LED was actually on?t = 4.7 It did agree.
4. Cause the LED to light and touch pin 4 to ground before the LED would normally turn off. What happened?
It turned off the LED.
5. Change the value of C1 to 0.1µF. What do think will be the result of this change?The LED will turn off sooner.
6. Repeat the above steps to determine the actual effect of changing the capacitance. What happened?It turned off sooner as the capacitance went down.
7. You may also want to change the value of R1 to see its effect. What happened?It turned off sooner.
By the way, that IS my hand trying to get out of the way before the picture took.Any questions?
