555Timer. - Here is Circuit Schematic Piezo Trigger Switch based on IC555. Piezo Trigger Switch circuit described here is a microcontroller-compatible shock/impact sensor switch module works on 5VDC supply. The whole circuit can be assembled on a 5×7 cm common circuit board. The piezo-ceramic element (PZ1) can also be mounted on the PCB without any difficulty. The module gives a “Logic-High” (H) output when the sensor (PZ1) detects a valid shock/impact. By default, this high signal is available for a period of near 1 second. However you can change this by modifying the value of the RC time constant components in the CMOS monostable circuit built around M7555CN (U1).
|Figure 1. Schematic Piezo Trigger Switch based on M7555CN|
Component List :
- IC1: M7555CN (from NXP)
- D1: 1N4148
- LED1: 5mm/3mm Red
- PZ1: 27mm Piezo-Ceramic Element (Piezo-Disc)
- R1: 4.7M ¼ w
- R2: 100K ¼ w
- R3: 100K ¼ w
- R4: 1.5K ¼ w
- C1: 1KpF (102) Ceramic
- C2: 10uF/16V Tantalum(Plastic Washer for the Piezo: 25mm outer diameter x 20 mm inner diameter x 2mm thickness)
The Original article : "Piezo Trigger Switch Circuit"