basically a transistor will allow a 'higher' voltage/current pass through it (to the target device)....(unaffected..ie: not regulated or anything)... by allowing a 'smaller' voltage/current to 'toggle' the gate and allow said 'flow'...
Yes. Bear in mind that a BJT is a current-controlled device, unlike a mosfet which is voltage-controlled.
(Vcbo) Collector Base = 50v
(Vceo) Collector Emitter = 45v
(Vebo) Emitter Base = 5v
Does that mean it can have up to 50v connected (from battery/source)...
output up to 45v to the 'target' device..
and can take 'up to' 5v (max) to toggle/control the gate?
No. it can have up to 45V connected from the battery (Vceo). The Vebo rating means that if for some reason you apply a negative voltage to the base, it had better not go more negative than 5V.
Im also confused about the current ratings given.. it is 200mA available or 500mA available? what are the difference between the two numbers given?
(Ic) Collector Current = 500mA
(Ibm) Peak Base Current = 200mA
The collector current rating is the one that matters, along with the power dissipation rating.
basically jumper/bridge from the battery +/- pads from the first pcb to the second.....
but more importantly.. could I use the same PWM pin to control/fade BOTH pcb's at the same time??
Yes, provided that the current draw from the Arduino pin is below its 40mA limit. Currently you have 1K base resistors, so the current draw from the pin per board connected is only about 4.5mA.
my question is.. if the one resistor I use, limits the current to, say, ...40mA going to the 5050 led/unit... how will the leds respond/behave?
Will all 3 leds split the '40mA' equally? will one leds take more? or full mA leaving the others without full or equal current?
They will probably share the current fairly evenly but not perfectly. Best option would be to use a high enough voltage battery so that you can connect the 3 LEDs in series. Then the current draw remains 20mA per 5050 (assuming you want to run the individual LEDs at 20mA).
in the current example. if I changed to 5050 leds.. there are 5 leds.. going to all 5 x 5050 leds would be (5 x 60mA = 300mA) neded per pcb/board!!
Im not even sure the transistor can handle/provide that?.. however if @ 40mA each 5050 led looks and acts fine.. it might be a viable option... (or maybe just more 1206 leds!) lol.. but I 'am' curious.
Connecting the LEDs in series and using a higher voltage supply addresses that issue. But 300mA may be just OK for a BC817 if you reduce the base resistor from 1K to 220 ohms