Seconds Since Last Injury

An LED counter increments every second. Pressing the button delivers a 48,000 Volt shock and resets the counter to zero. Hilarity ensues.

Hardware Requirements

• 4x 7-segment LEDs (12-inches tall, common cathode)
• 1x Nova Violet Wand (Model SN-B)
• 1x P10 SMD LED Sign 40"x8"
• 1x Arduino Mega
• 1x Adafruit Feather 32u4 Basic Proto
• 4x TPIC6C595N bit shifters
• 28x TIP125 PNP transistors
• 28x 68Ω resistors
• 28x 2KΩ resistors
• 2x 1KΩ resistor
• 1x 22KΩ resistor
• 1x 7.5Ω resistor
• 1x .22uf capacitor
• 2x IR LEDs
• 1x IR Receiver
• 1x PN2222 Transistor
• 5x proto boards
• 1x button
• 1x 24V Power Supply
• 1x 9V Power Supply

Wiring

Notes for reducing EMI

• Create a compartment for the Violet Wand, wrap it in aluminum foil, and ground it (earth ground AND via extension cord).
• Wrap cables generously with ferrite beads.
• Keep counter board suspended above (and insulated from) the ground.
• An Isolation Transformer may or may not be helpful.