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 ( DTL diode-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.

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).

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