1.1.4 7-segment display - only one resistor?

Learning kit for Raspberry Pi
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Going through the SunFounder Raphael Kit for Raspberry Pi

In Lesson 1.1.2 - RGB LED, we had to put a resistor on EACH of the anode pins.
In Lesson 1.1.3 - LED Bar Graph, each of the TEN LEDs needed a resistor

I am having trouble understanding why Lesson 1.1.4, which deals with seven LEDs on the display, we only use a SINGLE resistor?

Thanks.

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You are correct that a 7‑segment display contains seven LEDs (plus the decimal point, making eight). However, these LEDs are driven in a high‑speed multiplexed fashion – only one segment is lit at a time, but they cycle so quickly that they appear to be all on simultaneously.

Because only one LED is actually active at any given moment, a single resistor on the common cathode or anode line is sufficient to limit the current for that one active LED.

That said, it is also common practice to put a resistor on each anode pin for added safety and to ensure consistent brightness across segments. Both approaches work – the single‑resistor method is simpler and still safe for this multiplexed setup.

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Thanks again. Really impressed by the explanations I am receiving on the forum.

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Glad to help. Further help,please feel free to contact.

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