A LED light bulb is being popularity more than a conventional light bulb. Because It has high efficiency, low power consumption and thus heat resistant.
Figure 1 LED light bulb for Car.
Then I tried to measure the current flowing through it is only about 20mA As Figure 2.
I try to used a different LED super bright circuit as Figure 3.
As usual, it will take voltage of around 1.8V-4V and a current of about 10mA. When we want to keep it low power consumption. We also used a series or We bring 3 LEDs in series. If the voltage across each it is approximately 3V cause current to flow through approximately 10mA.
The diode is used for protect revers voltage to LEDs but it will reduce voltage down from 12V into 11.3V. As principle of it.
And use R- Resistor limits current to the 3 LEDs. You may use formula below.
R = (11.3V- LEDVolts)/ LED currents
– LED voltage = 3Vx3 = 9V
– LED currents = 10mA
= (11.3V – 9V)/ 10mA = 300 ohms
But I use 330 ohms 0.25W
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