Introduction: 555 Timer Circuits
The 555 Timer uses 3 main functions: Astable, Monostable, and Bistable. The Astable outputs a high pulse on a steady repetitive pace. The Monostable when triggered holds the output high for a predetermined time period. The Bistable can be held high and low by pressing the pushbuttons. If you want to learn more, visit RealCircuits.com.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Astable 555
This build can be used in a variety of circuits: Timers, clocks, drive servo motors, and IR Sensors. The Astable is able to do this because it can change the cycle from milliseconds to minutes using two resistors and a capacitor.
Step 2: Monostable 555
Using the monostable, you can output a high pulse for a preset time period. Using a capacitor and resistor, the time period can vary from milliseconds to minutes.
Step 3: Bistable 555
Another way to think about this circuit, is simply as a switch. If you press the bottom pushbutton the LED will go high and pressing the top pushbutton it will stay low.