PAGE 105 OF 150 · DISPLAYS & INDICATORS
Queue Number Token Displays
Large digits let people read numbers from far away.
LED SYMBOLTriangle points from anode to cathode; the arrows show light leaving the part.
Simple queue display
Queue number displays count customers up. A button advances the number, another resets it, and a bell can sound on each change.
Design points
- Two or three large seven-segment digits are readable across a room.
- A wireless 433 MHz remote lets staff change the number from a distance.
- Store the number in memory so a power cut does not lose it.
Wrap from 999 back to 1 and make the reset button hard to press by accident.
REMEMBER
Large digits and a protected reset keep a queue display reliable.Try it yourself
Sketch the circuit on paper first, calculate the values, then build it on a solderless breadboard using a low-voltage supply. Measure with a multimeter before you make anything permanent.
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