i just wana ask if u can give me a simplified circuit of a 7 segment display using only 2 digits, I badly need it.. It is supposed to be connected to an LDR (Light dependent Resistor, SENSOR) which makes it au2matic.
i.e when a kind of load passes thru the LDR the 7 SEGMENT Display will automaticaly count it, Can u please help me? Im confused on what to do coz I dont actually know the entire circuit when it uses 2 digit.. Please ^_^. I'll wait for ur reply, Thank You, God Bless.
i just wana ask if u can give me a simplified circuit of a 7 segment display using only 2 digits, I badly need it.. It is supposed to be connected to an LDR (Light dependent Resistor, SENSOR) which makes it au2matic.
i.e when a kind of load passes thru the LDR the 7 SEGMENT Display will automaticaly count it, Can u please help me? Im confused on what to do coz I dont actually know the entire circuit when it uses 2 digit.. Please ^_^. I'll wait for ur reply, Thank You, God Bless.
@mpaillali : oh ok. 0-14.thanks for the reply. im using sn74ls90(texas instruments) and hd74ls48p(unknown manufacturer) to count 0-9 but sometimes noticed the inverted-F( HHHL ) appearing initially then blank(HHHH) then 6(LHHL) at my display and loops properly. but my DM7490 works perfect. btw, on your vid, noticed the zero(LLLL) doesnt appear at the first few loops. im thinking of shifting to DM7490AN(unknown manufacturer), since it displays the figures i needed.
Hi Karlbox, thanks for your post, if you are talking after the 9th segment it's because the IC count 0 - 14, for that reason the IC represent some segments with not light up. I'm using only one segment for the count
i made a counter like that too. and some segments does not light up(broken numerical display), also similar to the one on this video? any idea about that? it's already soldered. sometimes it display ok. sometimes, broken. bad IC?
@mpaillali I have a question for you. Between the 1st and 2nd pin of the pulse generator you placed a 16 uF polarized capacitor. But there is no such value for a polarized capacitor. Only 10 uF and 22 uF. Which one should i use? Probably the 10 uF, right? Please help.
hi.. i think this video is amazzzing.. please help me out.. can you re do the video in english? im trying to build a board that can count upto 5 digits..a maximum of 99,999 units... and the numbers have to be triggered by a IR beam.. please help meeee. cheers
put a phototransistor on pin 14 of the 74ls90 and align an ir led to the phototransistor when something crosses between the two the phototransistor will make a pulse that triggers the 74ls90
hi mpaillali,
i just wana ask if u can give me a simplified circuit of a 7 segment display using only 2 digits, I badly need it.. It is supposed to be connected to an LDR (Light dependent Resistor, SENSOR) which makes it au2matic.
i.e when a kind of load passes thru the LDR the 7 SEGMENT Display will automaticaly count it, Can u please help me? Im confused on what to do coz I dont actually know the entire circuit when it uses 2 digit.. Please ^_^. I'll wait for ur reply, Thank You, God Bless.
alwaysforyou1 5 months ago
hi mpaillali,
i just wana ask if u can give me a simplified circuit of a 7 segment display using only 2 digits, I badly need it.. It is supposed to be connected to an LDR (Light dependent Resistor, SENSOR) which makes it au2matic.
i.e when a kind of load passes thru the LDR the 7 SEGMENT Display will automaticaly count it, Can u please help me? Im confused on what to do coz I dont actually know the entire circuit when it uses 2 digit.. Please ^_^. I'll wait for ur reply, Thank You, God Bless.
alwaysforyou1 5 months ago
Hi!
I need a scheme for a counter with up and down with 2 digit + reset Can you help me please?
djklaussro 9 months ago
oye no tienes algo parecido pero para contar del 0 al 15???
luisflores1000 9 months ago
@mpaillali : oh ok. 0-14.thanks for the reply. im using sn74ls90(texas instruments) and hd74ls48p(unknown manufacturer) to count 0-9 but sometimes noticed the inverted-F( HHHL ) appearing initially then blank(HHHH) then 6(LHHL) at my display and loops properly. but my DM7490 works perfect. btw, on your vid, noticed the zero(LLLL) doesnt appear at the first few loops. im thinking of shifting to DM7490AN(unknown manufacturer), since it displays the figures i needed.
karlbox 1 year ago
Hi Karlbox, thanks for your post, if you are talking after the 9th segment it's because the IC count 0 - 14, for that reason the IC represent some segments with not light up. I'm using only one segment for the count
mpaillali 1 year ago
i made a counter like that too. and some segments does not light up(broken numerical display), also similar to the one on this video? any idea about that? it's already soldered. sometimes it display ok. sometimes, broken. bad IC?
karlbox 1 year ago
Hi, thanks for your message, in Chile is very easy and cheaper, if U want this IC, I can send a couple of them by UPS.
mpaillali 1 year ago
@mpaillali I have a question for you. Between the 1st and 2nd pin of the pulse generator you placed a 16 uF polarized capacitor. But there is no such value for a polarized capacitor. Only 10 uF and 22 uF. Which one should i use? Probably the 10 uF, right? Please help.
ciocanelel 1 year ago
i just wanna ask where can i get the 74ls147 ic from?
matthewhhchan0820 1 year ago
Interesting, can do you have a better resolution pictures?
AppleFreak111 2 years ago
now you just need to use the over flow to power the other side of the digit display and then count to 99
mccunecp 2 years ago
hi.. i think this video is amazzzing.. please help me out.. can you re do the video in english? im trying to build a board that can count upto 5 digits..a maximum of 99,999 units... and the numbers have to be triggered by a IR beam.. please help meeee. cheers
nissangaw 3 years ago
put a phototransistor on pin 14 of the 74ls90 and align an ir led to the phototransistor when something crosses between the two the phototransistor will make a pulse that triggers the 74ls90
myx1997 2 years ago
Thanks for your post, I´ll do it, Saludos
mpaillali 2 years ago