ribbon carbon convertor

em wave

Electromagnetic

-磁鐵
-optocoupler 4n35

to avoid the sound

Ohm's Law

I = amp (current)
V = voltageR = ohm (resistor)P = W (joules per sec)

I=V/R P=IV

A Guide to Understanding Battery Specifications

• http://web.mit.edu/evt/summary_battery_specifications.pdf

Arduino 101 Phone via blurtooth

Laser printer Destruction

Windshield Wiper Motor

https://en.wikipedia.org/wiki/Linkage_(mechanical)