Diy Christmas lights: Difference between revisions
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* White: 3.3 V | * White: 3.3 V | ||
Seven blue leds makes <math>2.9 | Seven blue leds makes <math>7\times 2.9 V =20.3 V</math>, and white blue leds drops the voltage by <math>7\times 3.3V=23.1 V</math>. | ||
If we use simple AA batteries, we will need <math>14\times 1.5= 21 V</math> or <math>16\times1.5 = 24 V</math>. Quite many. . . | |||
If we use simple AA batteries, we will need <math>14\times 1.5= 21 V</math> or <math>16\times1.5 = 24 V</math>. Quite many. . . | |||
However, if we wire them alternately, it makes <math>3\times2.9V=8.7V</math> and <math>4\times2.9V=11.6V</math> for blue led and <math>3\times3.3V=9,9V</math> and <math>4\times3.3V=13,2V</math> the white leds. | |||
=== Photodiode and transistors === | === Photodiode and transistors === | ||
== result == | == result == | ||
Revision as of 20:48, 13 November 2022
Introduction
Make a simple battery powered Christmas light with seven (7) leds.
Theory
Use leds in series, as parallel leds might light on uneven brightness.
LEDs and wiring
- Red and yellow led: 2 V
- Green and blue led: 2.9 V
- White: 3.3 V
Seven blue leds makes , and white blue leds drops the voltage by . If we use simple AA batteries, we will need or . Quite many. . .
However, if we wire them alternately, it makes and for blue led and and the white leds.
