Strange Clocks

Resistor Clock

Ohms tell the time

How to read it

  1. Each band is one digit of HH:MM.

  2. Black=0, brown=1, red=2, orange=3, yellow=4.

  3. Green=5, blue=6, violet=7, gray=8, white=9.

  4. 17:35 reads brown-violet-orange-green.

The story

Around 1930 the Radio Manufacturers Association backed a color code so tiny resistors could show their value without printed digits; the familiar bands became its standard by 1941. Here the four bands encode HH:MM.

Year
c. 1930
Place
United States
Creator
RMA (radio industry)

Fun fact

Electronics students memorize the sequence with mnemonics — most of them unprintable.

Learn to read time again.

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