What do the transistor do on the display board.

ronsimpson

Joined Oct 7, 2019
3,131
This kind of a display has only one digit at a time lit up. Each digits is on for 1/6. All 6 digits are refreshed faster than the eye can see.
Lines A,B,C,D,E,F,G turn on the 7 segments. The transistors turn on only one digit at a time.
 

panic mode

Joined Oct 10, 2011
2,796
yup... each digits is flashed briefly, then the next one... and the next one... etc.
when this is done fast enough, it looks stable to our (slow) eyes.
note that in that circuit only the 7-segment displays are multiplexed.
the 8th segment (decimal point LED) is not... (circled in blue)
 

Thread Starter

Salt_Mud3871

Joined Mar 11, 2024
3
This kind of a display has only one digit at a time lit up. Each digits is on for 1/6. All 6 digits are refreshed faster than the eye can see.
Lines A,B,C,D,E,F,G turn on the 7 segments. The transistors turn on only one digit at a time.
Thank you for the explanation. Salt_Mud
 

Thread Starter

Salt_Mud3871

Joined Mar 11, 2024
3
yup... each digits is flashed briefly, then the next one... and the next one... etc.
when this is done fast enough, it looks stable to our (slow) eyes.
note that in that circuit only the 7-segment displays are multiplexed.
the 8th segment (decimal point LED) is not... (circled in blue)
Thanks for the explanation. Salt_Mud
 
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