TechCrate 005 — Lucky Number Spinner

Hold the button to spin a glowing number, then let go to stop on a digit. Build with a 555 timer and 4026 counter, and explore the optional resistor challenge.

• 1 × 555 timer chip
• 1 × 4026 counter chip
• 1 × common-cathode number display
• 1 × two-pin pushbutton
• 9 × 10K resistors
• 1 × 47K resistor
• 1 × 100K optional-challenge resistor
• 1 × 1µF (105) capacitor
• 1 × 0.01µF (103) capacitor
• 2 × 0.1µF (104) capacitors

Breadboard, 9V battery, Battery snap connector, Jumper wires.

Subscriber instructions PDF · Build video and customer files

Optional: compare the timing resistor values with power disconnected, then explore how they affect the spinner. The complete build and its checks work without a meter.

ProTechTrader Large Screen Digital Multimeter PDM-711