LED Scanner circuit

Published:2012/9/25 0:50:00 Author:muriel | Keyword: LED，Scanner | From:SeekIC

Here is a simple LED chaser simulating a scanner through the back and forth light effect. It used high bright White LEDs to give the chaser effect. The circuit uses an oscillator to produce fast pulses and a decade counter to drive the LEDs.IC1 is designed as an astable multivibrator to give continuous positive pulses to the decade counter. Variable resistor VR1, R1 and C1 form the timing components. By adjusting VR1, it is possible to change the speed of the scanning LEDs. Output pulses from IC1 are fed to the clock input of the decade counter IC2. Resistor R2 keeps the clock input of IC2 low after each positive to negative transitions of input pulses. This is necessary because sometimes the clock input of the decade counter stays positive and does not accept input pulses. LED Scanner Circuit Note: This circuit can be used to drive AC loads like 60 watts bulbs for decoration purpose. For that slight modification is necessary. Connect the cathode of LED to the gate of a Triac (BT136) through a 220 ohms resistor. Connect bulb to the M2 pin of triac in series with the phase line as shown in the diagram. Six 60 watts bulbs can be connected serially to each triac (BT136 is rated to 400 watts).



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Measuring_and_Test_Circuit/LED_Scanner_circuit.html

Print this Page | Comments | Reading(3)