They turn 10mA from a digital pin into 1A from the power supply. You would need 7 635's, one for each layer. Collector pin goes to 5V, Emitter pin goes to all the LED anodes on a layer, Base pin connects in series to a 510Ω or 470Ω resistor and an Arduino digital pin. To source current, BC635's are rated up to 1A with a typical current gain (hFE) of 100. You can daisy chain the serial in/outs on them so you just need to shift out 8 bytes from the Arduino (either using SPI or the software equivalent, shiftOut or whatever it's called, on any digital pin.) The 595's can sink up to 150mA each (so up to 8 LEDs at 18.75mA each, use a 270Ω resistor in series with each LED if you're running everything from 5V.) You would need 7 595's for 49 LEDs (49 / 8 rounded up.) ![]() ![]() If it were me, I'd use some TPIC6B595 IC's to drain current and BC635 NPN's to source it. With external circuitry however, anything is possible. So yes, you will not be able to drive that load directly from the Arduino. ![]() The ATmega 2560 (assuming that's the chip on your Arduino Mega) has an absolute limit of 40mA on each pin, and 200mA in total for all pins.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |