This is a 10 cm diameter wheel made of FR-4 (typical PCB material) that combines Ohm’s Law and Joule’s Law into one handy reference chart. To calculate one of the inner quantities, use two known quantities and the appropriate outer expression. Example: the power dissipated by a 1 kOhm resistor with 100 mA flowing through it is P = I2R = 0.12 A * 1000 Ohm = 10 W. This particular relationship is called Joule heating or Joule’s first law.
The reverse side features the likenesses of Georg Simon Ohm and James Prescott Joule. Electrical engineers, technicians, and hobbyists alike utilize these laws on a daily basis.
Available in green/gold, black/gold, red/gold, and laser etched wood. Note: The wood version does not have the portrait of Ohm and Joule on the back.
“If I have seen further, it is by standing on the shoulders of giants.”
— Excerpt from a 1675 letter from Sir Isaac Newton to Robert Hooke
- 1.6 mm thick FR-4, immersion gold finish (wood version is 5 mm thick)
- One hole provided for mounting or hanging
If you know a friend or family member who would appreciate a PCB medallion with custom artwork on it as a gift (e.g. a picture of a pet, loved one, etc.), we’d love to help you get some manufactured. They also make great Christmas ornaments. Please contact “parts (at) proaudioe.com” for more information. We can order as few as 5 PCBs.