LM3914 --help :/

[[email protected]]

Hi all!


Could someone explain me how does design from page 12 of
http://boss.iele.polsl.gliwice.pl/pdf/National_Semiconductor/lm3914.pdf

works.


Why all the LEDs are blinkink while the last one begins to lighth ??


Best regards


DM

 

[Ryan Weihl]

Hi all!


Could someone explain me how does design from page 12 of
http://boss.iele.polsl.gliwice.pl/pdf/National_Semiconductor/lm3914.pdf

works.


Why all the LEDs are blinkink while the last one begins to lighth ??


Best regards


DM

noise, make sure you add caps to filter the VCC and input
rw

 

[[email protected]]

no the it blinks as it should in that configuration shown on 12th page,
but i do not undrestand why it blinks ...the idea ...could someone
easely explain that ?

David

 

[Ryan Weihl]

no the it blinks as it should in that configuration shown on 12th page,
but i do not undrestand why it blinks ...the idea ...could someone
easely explain that ?

David

ok, now change the voltage on the input and you
should see different led's turning on and of.
The blinking led's mean noise on the input
voltage.
rw

 

[Ryan Weihl]

no the it blinks as it should in that configuration shown on 12th page,
but i do not undrestand why it blinks ...the idea ...could someone
easely explain that ?

David

ok now after reading you question again I understand what you mean.
I did use this display, thats why I answerd. The blinking is controlled
by the mode pin. see page 7 (and 8). I only used it dot mode as
an amp-meter.
rw

 

[[email protected]]

i have read p 7 and 8 and it doesn't say anything bout blinking i
thionk that blinking is controlred by feedback capacitor but m not
ssure .. what do u thing bout that?

david

 

[[email protected]]

take a look at pa 12 design with alarma flasher that ios what i am
talking bout, but i do not understend the idea of blinking

 

[Ryan Weihl]

take a look at pa 12 design with alarma flasher that ios what i am
talking bout, but i do not understend the idea of blinking

look at page 7: Mode Pin use.
Dot display: leave the mode select pin open
Bar graph display: Wire Mode Select(pin 9) directly to pin 3
next: Dot or Bar mode selection, gives you details on what the
mode pin does.
Hope this helps
rw