1. A Second Identical Exhibit Make a parallel exhibit using fluid components: Generator → Pump with reservoir Resistors → Throttling valves Transistors for PWM → High speed solenoid valve Light bulb → Fan connected to fluid motor Power meter → Tachometer Switching transistors → 3-way solenoid valves

2. Fluid Circuit

10. User Inputs for Both Exhibits A start button Spins the duty cycle wheel for 30 seconds Crank The user can spin the crank to deliver power Toggle switch Activates duty cycle or divider/throttler system Load power selector Varies the duty cycle and selects divider/throttler

11. The Activity 1. Hit start to spin wheel 2. Turn crank to deliver power 3. Switch between the parallel systems 4. Repeat at different duty cycles 5. Watch the system as the wheel slows down

12. Desired Results Understanding of PWM power efficiency User gets brighter bulb / faster fan using PWM system Understanding of electrical and fluid power The user feels the power input and sees the output Understanding of pulse-width modulation The dim bulb becomes a flashing bulb at the end Fun and interaction The user enjoys experimenting with the exhibits

13. System Layout

14. Current Design Designed for user accessibility Users of 40 to 70 inches tall Wheelchair accessible Designed for user friendliness Few user inputs Exhibits are back-to-back

15. Dimensions (inches) Current Design

16. Dimensions (inches) Current Design