Hot search:

Hot Digital Circuit

@WiringCircuit

>> Home > Digital Circuit > 9 Second LED Timer and Relay Circuit

9 Second LED Timer and Relay Circuit

2013-06-21 Posted by:circuit Source:Internet Visits: Comment () Size:L M S

Summary:9 Second LED Timer and Relay Circuit Circuit Description This circuit provides a visual 9 second delay using 10 LEDs before closing a 12 volt relay. When the reset switch is closed, the 4017 decade counter will be reset to the 0 count which

9 Second LED Timer and Relay Circuit

Circuit Description

This circuit provides a visual 9 second delay using 10 LEDs before closing a 12 volt relay. When the reset switch is closed, the 4017 decade counter will be reset to the 0 count which illuminates the LED driven from pin 3. The 555 timer output at pin 3 will be high and the voltage at pins 6 and 2 of the timer will be a little less than the lower trigger point, or about 3 volts. When the switch is opened, the transistor in parallel with the timing capacitor (22uF) is shut off allowing the capacitor to begin charging and the 555 timer circuit to produce an approximate 1 second clock signal to the decade counter. The counter advances on each positive going change at pin 14 and is enabled with pin 13 terminated low. When the 9th count is reached, pin 11 and 13 will be high, stopping the counter and energizing the relay. Longer delay times can be obtained with a larger capacitor or larger resistor at pins 2 and 6 of the 555 timer.

Circuit diagram

Circuit diagram
Good
(0)
0%
Bad
(0)
0%
Tags:digital
-------------------------------------
Circuit Notice

If the circuit&wiring in《9 Second LED Timer and Relay Circuit》was too small to read, you should download them!

@Wiring Circuit@

@New comment
      What's the feeling for you?
      Face:
      Comment:
      Change the code
      * Ctrl+ENTER To Sent

      @READ EXPLANATION

      ☉If you have any questions, please don't mind to tell us.