MrDEB
Well-Known Member
In this project I need more pcboard real estate. The tip120 takes up too much room.
Thought about using 8 - 2n2222 transistors in parallel.
according to calcs?? one - 4 led array = 450ohms
the 2n2222 = Ic = 800ma, beta = 75
the circuit -- Vcc = 18v
Load = 450 ohms
base voltage = 1v
emitter current = 300mv
running each array at 30ma
the 7556 has an output current of 50ma
Just never saw transistors in parallel??
note - the circuit has 8 - 1/2" x 4" boards. thinking of putting each 2n2222 on each board and large traces for power and ground between boards.
using **broken link removed** for transistor simulation
each LED as of right now (looking at using SMD LEDs) 3.4 voltage drop (white)and running at 30ma (might increase as only flashing at 50ms.
Thought about using 8 - 2n2222 transistors in parallel.
according to calcs?? one - 4 led array = 450ohms
the 2n2222 = Ic = 800ma, beta = 75
the circuit -- Vcc = 18v
Load = 450 ohms
base voltage = 1v
emitter current = 300mv
running each array at 30ma
the 7556 has an output current of 50ma
Just never saw transistors in parallel??
note - the circuit has 8 - 1/2" x 4" boards. thinking of putting each 2n2222 on each board and large traces for power and ground between boards.
using **broken link removed** for transistor simulation
each LED as of right now (looking at using SMD LEDs) 3.4 voltage drop (white)and running at 30ma (might increase as only flashing at 50ms.