LED Cube/Column Resistors in Detail: Unterschied zwischen den Versionen
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Marvin (Diskussion | Beiträge) Keine Bearbeitungszusammenfassung |
Marvin (Diskussion | Beiträge) Keine Bearbeitungszusammenfassung |
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* Voltage drop on the LED | * Voltage drop on the LED | ||
For now, we are only interested in the resistor value for one specific LED color (and also only one type as a color may be created using different techniques which results in different forward voltages), thus only one LED forward voltage has to be taken into consideration. Also we assume that the USB voltage is 5.0 Volts which is okay, as we will see. Now we are at a situation where we have five volts which will be divided onto our components. Also, we are going to make this calculation only for 20 mA current per LED, however, you can make your own calculations quite easily. | For now, we are only interested in the resistor value for one specific LED color (and also only one type as a color may be created using different techniques which results in different forward voltages), thus only one LED forward voltage has to be taken into consideration. Also we assume that the USB voltage is 5.0 Volts which is okay, as we will see. Now we are at a situation where we have five volts which will be divided onto our components. Also, we are going to make this calculation only for 20 mA current per LED, however, you can make your own calculations quite easily. Let's have a look at the different I/V characteristics: | ||
==uC== | |||
==LED== | |||
==Transistor Array== | |||
==Resistor== | |||
Version vom 15. April 2012, 02:19 Uhr
Choosing the right column resistors for your LED cube requires you to consider several factors:
- Suitability of the cube base for different colors
- Expected USB voltage
- Voltage drop on the microcontroller
- Voltage drop on the transistor array
- Voltage drop on the LED
For now, we are only interested in the resistor value for one specific LED color (and also only one type as a color may be created using different techniques which results in different forward voltages), thus only one LED forward voltage has to be taken into consideration. Also we assume that the USB voltage is 5.0 Volts which is okay, as we will see. Now we are at a situation where we have five volts which will be divided onto our components. Also, we are going to make this calculation only for 20 mA current per LED, however, you can make your own calculations quite easily. Let's have a look at the different I/V characteristics: