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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 !

Subscribe to my YouTube channel ! SimpleTronic

<p>great project</p><p>can i place your project on my website.</p><p>i'm working on a website which is related to electrical projects.</p><p>i also mention your name.</p><p>plz reply</p>
<p>I will feel very proud seeing the project on your website. Thank you!!</p>
<p>I just hope one day I understand what you two very clever guys are talking about.</p><p>Great project, but beyond me yet</p><p>Thanks John :) </p>
<p>Aa microcontroller might be overkill, but it has some serious advantages over most discrete solutions. They're far smaller (such as the attiny10 in an sot23-6 package) and require way less external components. But their biggest advantage is the possibility to use them a a wide number of projects, allowing me to by them cheap in bulk.</p><p>However, this is great as a build-and-done, without the need of writing code and the equipment to flash it onto the controller. Perfect for beginners.</p><p>Thank you for continiously contributing awesome circuits to this community, imho you receive way to less recognition for you efforts. :)</p>
<p>Yes, <strong>attiny10</strong> is a versatile <em>microcontroller</em> (I prefer <strong>PIC</strong>s &amp; will upload my designs soon) now, max output current of attiny is <strong>40mA</strong>. For a LED chaser circuit you will need an output transistor/fet per channel unless you want a 3 led chaser. These transistors will need current limiting resistors for base &amp; collector. In the end, you will be using as many components as me! .</p><p>Yes, I would love to have more followers (maybe my circuits are a bit complex to understand) but as long as I have at least <em>one</em> showing interest in what I have learned (in this case You) that&acute;s enough for me ! Thanks!</p>
<p>I don't know I you knew that, but you can also use the internal pull-up as a npn transistor base resistor.</p><p>You would save 4 resistors, 4 diodes and on capacitor total. ;)</p>
<p>Yes, a nice feature of attiny is to enable pull-up resistors for individual port pins, now the value of these R&acute;s can be up to 50Kohms and with a 5v Vcc supply, the current may be too low to fully drive a power bipolar transistor. It would be perfect though for a FET. You can even drive the fet directly from the port pin (configured as output) with pull-up disabled.<strong> ---|&gt;|---</strong></p>
<p>Oh yeah, I forgot the transistor shoud drive more than one LED. Even with a minimum gain of 250 (bc807/817-40) only 250*(5V-0.7V)/50k=21.5mA would flow through the transistor. Thanks for that hint!</p><p>Anyway I'd still add a high value pull-down to the gate of the mosfet to make sure it stays off during reset. A semi swiched state could damage the mosfet over long terms.</p>

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Bio: Music: my profession for over 40 years... Electronics: my beloved hobby always.
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