Introduction: LED Chaser ( Single Chip Circuit )
There are zillions of LED chaser circuits and most of them use 1 integrated circuit for the sequence (e.g.,CD4017) and another for the clock (e.g.,555). Some go even further and use a microcontroller (overkill). This simple circuit uses only a CD4060 cmos I.C. for both functions. and can drive up to 800mA worth of LED´s (around 35 in parallel) for each of the 3 channels. CD4060 is a ripple binary counter and does not have decoded outputs as the CD4017, but we can easily decode decimal 0 with diodes ( DTLdiode-transistor logic gates ) . Decimal 1 and 2 are taken directly from the 2 least significant digits (LSD) . We will also decode decimal 3 to reset the counter back to 0.
Step 1: Overview
Step 2: Circuit Diagram & Main Components
IC1: CD4060 cmos 14 stage ripple binary counter plus oscillator
Q1: BC327 PNP transistor (800mA)
Q2-Q3: BC337 NPN transistor (800mA)
D1-D4: 1N4148 diodes
R1-R3: 100ohm for 5 parallel LED´s. (recalculate for more parallel LED´s) - Even more LED´s with higher voltage supply voltage (parallel-series connected led´s).
Step 3: CD4060 Decoding of 0 - 1 - 2 - 3
Step 4: CD4060 - Ripple Binary Counter & Oscillator
Step 5: Decoding of Binary 00 ( Decimal 0 )
Step 6: Decimal 1 and 2 , Directly From Binary Digits 0 and 1
Step 7: Decoding of Decimal 3 From Binary (11) - Resets Counter to 0
Step 8: R5 and C1 Determine Clock Frequency (chaser Speed)
Step 9: Watch the Video. Thank You !
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