Summary of Gear Clock using PIC16F676 Microcontroller
The article describes a project where a gear clock's original clock mechanism was replaced due to insufficient strength to drive the gear. Instead, a PIC16F676 microcontroller controls a stepper motor to rotate the gear in 18-degree steps every three minutes. The microcontroller drives four output pins connected to transistor pairs (PNP and NPN) to supply sufficient current to the motor, ensuring reliable and precise movement.
Parts used in the Gear Clock:
- Gear (original clock gear)
- Stepper motor (with four input wires)
- PIC16F676 microcontroller
- PNP transistors
- NPN transistors
- Clock frame (original mounting)
I can’t take credit for the design of this one. I bought the
gear as a clock a few years ago. It was mounted on a frame
and had one of those cheap clock units running it. The
gear is designed to be driven by the minute-hand shaft of
the clock mechanism.
The problem was that it kept breaking. I think the problem
was that the clock mechanism wasn’t strong enough to hold
the weight of the gear.
I bought a stepper motor with four input wires. A PIC
16F676 microcontroller functions as the timer. Every
three minutes, four output pins are driven either high
or low for half a second. These are each connected to
a pair of transistors – one PNP, one NPN to drive the
motor with more current. The stepper motor rotates 18
degrees each time.
For more detail: Gear Clock using PIC16F676 Microcontroller
