Title:
28-LED-Clock-Timer-Circuit-Schema-With-74HCT
Download
- Category:
- Project Design
- Tags:
-
- File Size:
- 8kb
- Update:
- 2012-11-26
- Downloads:
- 0 Times
- Uploaded by:
- aliosx
Description: 28 LED Clock Timer Circuit Schema With 74HCT
This is a programmable clock timer circuit that uses individual LEDs to indicate hours and minutes. 12 LEDs can be arranged in a circle to represent the 12 hours of a clock face and an additional 12 LEDs can be arranged in an outer circle to indicate 5 minute intervals within the hour. 4 additional LEDs are used to indicate 1 to 4 minutes of time within each 5 minute interval.
The circuit is powered from a small 12.6 volt center tapped line transformer and the 60 cycle line frequency is used for the time base. The transformer is connected in a full wave, center tapped configuration which produces about 8.5 volts unregulated DC. A 47 ohm resistor and 5.1 volt, 1 watt zener regulate the supply for the 74HCT circuits.
To Search:
File list (Check if you may need any files):
28-LED-Clock-Timer-Circuit-Schema-With-74HCT.gif
