problem with leds in arduino

ericgibbs

Joined Jan 29, 2010
21,439
hi Dabu,
The drive transistors for D9/10 are PNP, so if the Arduino pins D8 and D9 are Low 0v, the transistors are On..
E
 

ericgibbs

Joined Jan 29, 2010
21,439
hi,
Thats not what you said., you did say you were pulsing them Hi/Low
when i turn on the 7 volt power supply led 9 and 10 are always on

EDIT:
If pins D8 and D9 a switched to +5V and the PNP Emitters are at 5V the transistors should be Off.

 

Thread Starter

Dabu WhiteHacker

Joined Sep 5, 2017
68
hi,
Thats not what you said., you did say you were pulsing them Hi/Low
when i turn on the 7 volt power supply led 9 and 10 are always on

EDIT:
If pins D8 and D9 a switched to +5V and the PNP Emitters are at 5V the transistors should be Off.
sory i forget the emiiter was not at 5 volt :p
my mistake
 

ericgibbs

Joined Jan 29, 2010
21,439
Measure the pins D8 and D9 actually are at +5V, if for example the Arduino output was say only 4V the transistors would still be ON.

EDIT:
If the Emitters are at 7V a 5V Base signal will not switch them Off...:rolleyes:
 

Thread Starter

Dabu WhiteHacker

Joined Sep 5, 2017
68
Measure the pins D8 and D9 actually are at +5V, if for example the Arduino output was say only 4V the transistors would still be ON.

EDIT:
If the Emitters are at 7V a 5V Base signal will not switch them Off...:rolleyes:
bro that is working awesome
you are best (y) have a nice day :D
 
Top