7-Segment LED Counter (binary and base 10) - Page 2 - Electronic Circuits Projects Diagrams Free

angst · 24th January 2008, 12:44 PM

Quote:

Originally Posted by Tom McCurdy

Here is something that I was able to build, it basically takes the pulse from a 555 timer and goes through a 7490 divide by 10 into a 7448 and finally into a LN514rk Common Cathode LED-- if you are going to use a common anode LED just replace the 7448 with a 7447

Materials Needed

5 V-Source
Wires
555-Integrated Circuit
7490-Integrated Circuit
7448-Integrated Circuit
7-Segment Display (the one I used was LN514RK)

Simply connect it as it is in the diagram
http://www.quantumninja.com/hw/elec/circuitdone.jpg

ei, can you send me a pcb design for this circuit,.using common anode,.,.
,.plz,.it would be a great help guys,...thank's.,.

e-mail;
eiluj_872001@yahoo.com

ArtoR · 21st February 2008, 08:55 PM

Hello!

I'd need help/advice of what can be wrong in my pulse counter.
It is based on 7490+7447+common anode 7-segment displays.
There are 3 phases, i.e. it counts from 000 to 999.

Generally everything's ok, but the pin 11 of the 7490's raise too often,
about randomly. It should raise every 10th pulse, right?
With oscilloscope I could see quick peaks in the 7490's Qx outputs.
What can be wrong? I've checked many times the connections
with magnification.

ArtoR · 21st February 2008, 08:59 PM

Here's the circuit. Pulses are generated from the LDR to the counter.
Button is for reseting the display.

I appreciate of comments.

mneary · 21st February 2008, 09:19 PM

I don't see any bypass caps. You should have a capacitor (I like 0.1uF for 7400 series chips) from 5V to GND near every chip. 0V probably should be connected to gnd.

The detector should have some hysteresis; see if a 7414 works better in place of the 7404.

Peter_wadley · 22nd February 2008, 03:31 AM

Yes a bypass cap is a def must with these counting chips.. when the number of LEDS which are on switches it can cause irratic behaviour..

ArtoR · 25th February 2008, 03:16 PM

Thank you for replies!
I'll do the modifications and tell you later how they work!

Arto

lanz · 27th February 2008, 03:05 AM

is the materials available here

ArtoR · 4th March 2008, 07:18 PM

Here's the fixed circuit.
In the previous circuit diagram I posted there is a drawing error: all the ground level voltages are connected into same potential.

Only improvement was that the 74LS04 needed to be changed to 74LS14.
Works!!
The pulses from the transistor were not so clean, so the counter incremented too much (with 74LS04).

This picture is of circuit that works.

Hero999 · 5th March 2008, 11:37 AM

Geat but you could save an IC if you don't mine an extra transistor and a few resistors.

TechnotroANIK · 23rd May 2008, 10:04 AM

Quote:

Originally Posted by jnkevin

Situation:
I have 3 7-segment display and i want it to display numers form 0-999.

The Problem :
Using a 7447 i can display from 0-9,A,B,C,D,E,F in one of the 7-segment display.
But how can i connect the 3 7-segment display in order to display from 0-999

m a high scl guy...m making a decimal adder circuit.....already done adddition part using 7483.
can display 0-9 in 7-segment. bt how do i do the A-F part??????
does it require any extra chip or something??????
help plzzz.
or i'll have 2 make sumthing to take carry bit frm 7483 and work on it..

BaCaRdi · 24th May 2008, 05:53 AM

Try spell-check first, Sorry my poor English translator is not functioning properly..lol

-BaC

Quote:

Originally Posted by TechnotroANIK

m a high scl guy...m making a decimal adder circuit.....already done adddition part using 7483.
can display 0-9 in 7-segment. bt how do i do the A-F part??????
does it require any extra chip or something??????
help plzzz.
or i'll have 2 make sumthing to take carry bit frm 7483 and work on it..

TechnotroANIK · 24th May 2008, 07:57 AM

to bacardi( sozzled, as the name suggests),
u can learn ur english in ENGLISH CLASSES.
try to help in the electronics part.
Abuses apart,
can someone send me the connection btwn a 7448 and 1050CHRI( common cathode 7-segment).

BaCaRdi · 24th May 2008, 08:14 AM

Damned them id10t errors...lol

Quote:

Originally Posted by TechnotroANIK

to bacardi( sozzled, as the name suggests),
u can learn ur english in ENGLISH CLASSES.
try to help in the electronics part.
Abuses apart,
can someone send me the connection btwn a 7448 and 1050CHRI( common cathode 7-segment).

kevlar_star · 26th May 2008, 11:45 AM

Quote:

Originally Posted by ThermalRunaway

In order to control two 7 segment displays using a circuit similar to the one above, you'd need two binary counters and two display drivers. The second binary counter would need to be clocked by the overflow of the first using some simple logic gates.

Brian

do you have the circuit...? so i could know the configurations..thanx

22nd February 2008, 03:31 AM	(permalink)
Peter_wadley Experienced Member	Yes a bypass cap is a def must with these counting chips.. when the number of LEDS which are on switches it can cause irratic behaviour.. __________________ "Stick around" - Arnold Schwarzenegger in The Predator after impaling a soldier to a wood post 9vDC Guitar Pedal PSU PIC16F84a Game Module

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21st February 2008, 08:55 PM	(permalink)
ArtoR New Member	Hello! I'd need help/advice of what can be wrong in my pulse counter. It is based on 7490+7447+common anode 7-segment displays. There are 3 phases, i.e. it counts from 000 to 999. Generally everything's ok, but the pin 11 of the 7490's raise too often, about randomly. It should raise every 10th pulse, right? With oscilloscope I could see quick peaks in the 7490's Qx outputs. What can be wrong? I've checked many times the connections with magnification.

21st February 2008, 09:19 PM	(permalink)
mneary Experienced Member	I don't see any bypass caps. You should have a capacitor (I like 0.1uF for 7400 series chips) from 5V to GND near every chip. 0V probably should be connected to gnd. The detector should have some hysteresis; see if a 7414 works better in place of the 7404.

25th February 2008, 03:16 PM	(permalink)
ArtoR New Member	Thank you for replies! I'll do the modifications and tell you later how they work! Arto

27th February 2008, 03:05 AM	(permalink)
lanz New Member	is the materials available here

24th May 2008, 07:57 AM	(permalink)
TechnotroANIK New Member	to bacardi( sozzled, as the name suggests), u can learn ur english in ENGLISH CLASSES. try to help in the electronics part. Abuses apart, can someone send me the connection btwn a 7448 and 1050CHRI( common cathode 7-segment).