Time Interval Relay Circuit for the clock circuit above 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 [...]
Device selection by 3-8 decoder At this circuit, the selection of seven devices are done using the decoder(74HC138). Device number Device 0 BCD-SW for 10th of the minute 1 BCD-SW for 1st of the minute 2 Start switch 3 Unused 4 7 segment LED for 10th of minute 5 7 segment LED for 1st of [...]
The simple ADC in the figure 1 is perfect for getting analog signals into a purely digital microcontroller. Using just five surface-mount parts, you can assemble it for less than 50 cents (1000), which is approximately half the cost of a single chip-ADC approach in the same volume. Moreover, this design takes only one pin [...]
