1. TOUCH ME NOT TOUCH ACTIVATED SWITCH Sharon Abraham 311

2. Criteria & Chosen Circuit  Possible to build Physical Circuit  Parts learnt about in class  Simple enough to model and understand  Learn about real circuit development  Get A in class  Chose Touch Activated Switch  Meets criteria  Interesting concepts

3. Circuit

4. Problems / Changes Circuit had both source and sink How to model human touch Removed one piece – used only sink Modeled as capacitor and pulse voltage source

5. Final Circuit Model

6. Simulation

7. Human Body Capacitance Sizable Capacitance Change Environmental Factors

8. Analysis Oscillator 20 kHz Shmitt Triggers Rails – Voltage sources

9. Oscillator

10. High Resistance Zero Current

11. Transistor – Diode – Only positive voltage

12. Amplifies Signal

14. Conclusion Circuit works as was expected

15. Uses Modifications Uses Modifications Elevator buttons Pool sensor Touch activated lamp - Addition of Flip Flops Alarm System - Output load is a siren