Albatroon:
And U are welcome in this board design post74595 PCB Design help ! - General Electronics - Arduino Forum
Long time posters tend to avoid helping cross-posters, as it creates double answers and wastes time.
Leo..
Wawa:
Not all eight channels 'on' at the same time I hope.
The ULN2803 can't have more than two channels 'on' at that current.
Leo..
Yes it can - but the limit is thermal, you get about 1/4W per channel at 0.25A, typically, so
I suspect 4 channels is probably going to be OK. The output devices are rated at about 1.1V
Vsat for those current levels, better than many darlington devices.
@Albatroon, why did you start another thread?
I thought the new post not related to this one.
This post for an issue with a design.
The other one is a new design..
Sorry for any inconveniences
MarkT:
Yes it can - but the limit is thermal, you get about 1/4W per channel at 0.25A, typically, so
I suspect 4 channels is probably going to be OK.
Agreed. Four is probably just ok if you don't mind a stinking hot chip.
How hot also depends ofgourse on board layout and airflow.
Bad practice to design for parts that can get too hot to touch (65C+).
Leo..
Thread locked. Do not cross-post again.