Zulushicage BC Datasheet The goal is to drive enough current through the base to make this happen. There must be hundreds, thousands of instructions out there on how to drive a LED with an Arduino, and the best method will be slightly different depending on the voltage drop across your LED. The series resistor at the gate is there to limit the switching current, and the resistor from gate to ground is there to make sure that the gate is not floating while the pin is in a high-impedance state that is, an input or turned off. This can be seen as a current booster. If you want to pass at most 20 mA through the collector, aim for 2 mA through the base, and you end up with a base resistor of about 2. This is not the way to do it.
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As you can see, there is no base resistor. Here is catasheet simplified schematic: The datasheet for the BC shows it as less than mV up to a collector current of mA. Since the output from the Arduino will be close to 5 volt, and V BE can be treated roughly as a diode, you will have about 4. Transistor Catalog The transistor datasgeet draw the absolute minimum amount of base current necessary to keep the right amount of current flowing through the collector. A circuit that relies on a specific current datashheet will simply not work well.
Just to be clear, your suggested circuit will put way too much current through the LED, and it will be poorly controlled. So using the formula: A conservative number is one tenth of the current through the collector. A forced beta of 20 is usually good. ChetanBhargava i salvaged this from one circuit and its laying in my bin.
If the 5V rail drops before the power to the Arduino, perhaps if they are powered from separate rails, all the current to the LED will come from the base, and thus from the Arduino. Post as a guest Name. Eatasheet as switch with Arduino Ask Question. There must be hundreds, thousands of instructions out there on how to drive a LED with an Arduino, and the best method will be slightly different depending on the voltage drop across your LED.
BC637 Bipolar Transistor
Equivalência de BC637