2. Transducers – changing one form of energy to another Piezoelectric Microphone Ultrasound Motors/Generators Switches Solenoids Relays EAPs Overview

3. Logic-level outputs can’t drive a motor directly. Solution: Relays –Relays allow one circuit to switch a second circuit –isolates circuit from potentially dangerous voltages

4. Main types of relays –Reed Relay –General Purpose Relay –Solid State Relay –Transistor

5. Advantages little power to energize Quiet Disadvantages Can’t control large loads Contacts can weld together

6. Advantages Can handle very large loads Control multiple contacts Disadvantages Physically large Mechanical failure

7. Advantages Fast switching Silent Disadvantages Higher cost Heat production

8. Advantages Fast switching Silent Low power/current Disadvantages DC only Small currents

9. Lead Screw Pneumatic Mechanical

10. –Converts rotary motion of a knob or handle into linear displacement via screw or gears Pneumatic / Hydraulic –Compressed air moves a piston inside the cylinder which moves the actuator directly. Lead Screw –Converts rotary motion via motor into linear displacement. A lead screw with helical threads machined on its circumference rotates, while a nut with corresponding helical threads moves the actuator linearly.

11. The Circuit Breaker Why? Chip Substrate Collapse Melting Fire Why not Fuses? Fuses: Inexpensive Fuses: More Reliable CBs: Can be Reset

12. Circuit Breaker: Trigger Mechanisms Magnetic: Field proportional to current in coil Tuned mechanical trigger Contacts are pulled apart in response to Magnetic force Thermal: Material bends or expands with dissipated heat Contacts pulled apart when spring-loaded trigger is released http://www.zlan.com/brk_info.htm Electronically-controlled: Controller reads current value from sensors Detects when current rises above a threshold Signals actuators to break contacts - - In high-power apps, sensors may need to be separated…

13. Arc Quenching Here is whyHere is why. High-voltage applications Prevents static discharge Even a small spark can ruin some equipment… Puff of air Channel to ground Vacuum chamber (most common)

14. - Uses electrical energy to produce mechanical work - Commonly used in refrigerators, washing machines, fans, pumps, and computer equipment Advantages - No fossil fuels - Noise reduction - Wide range of sizes - Fewer components Disadvantages - Less powerful - Battery limitations

15. Types AC Induction AC Synchronous Stepper DC Brush DC Brushless DC

16. -Transforms mechanical energy into electrical energy -Sources of mechanical energy include -Combustion Engines -Compressed Gas -Steam/Gas Turbines -Solar and Wind