LED Clock PCB Design

flux

Based on a typical white LED with a forward voltage of about 3V, a good approach is to use series strings of 3 LEDs. For a 12V DC supply:

Table

ParameterValue
LEDs in series3
Total LED forward voltage9V (3V × 3 LEDs)
Voltage left for resistor3V (12V − 9V)
Resistor (assuming 20 mA)150Ω (calculated as 3V / 0.02 A)
Layout Recommendation:
  • Use multiple series strings in parallel to cover your desired LED count for the clock design.
  • Each string should include 3 LEDs in series with a current-limiting resistor (typically around 150Ω for 20 mA) to ensure consistent and safe operation.
  • Arrange the strings according to your clock’s geometry (for example, in a circular pattern if you’re designing an analog clock or in a grid if you prefer a digital display).
This approach optimizes power usage by ensuring that most of the supply voltage is used to drive the LEDs rather than being dropped across the resistors.
If you have any further details about the total number of LEDs or the display geometry, I can help refine the layout further.
Define series strings for the clock
Optimize string layout for design
Adjust LED configuration
R1
Resistance
220 Ω
D2
PowerNet1
R2
Resistance
220 Ω
D1
  • Generic Inductor
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  • Generic Resistor
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Sweet Rose KITT

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Properties

Properties describe core aspects of the project.

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