A numeric display consisting of seven segments per digit, allowing characters 0 to 9 to be displayed by selecting which segment is on or off. Can have each digit independently controlled, or can be multiplexed to reduce pin count. An 8th segment can be included for a decimal point.

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1answer
232 views

Why did my resistor burn and what can I do to solve it?

I have tried to create a circuit to switch a large 7-segment LED display (LDS-CD16RI) using a pair of MOSFETs, as follows: simulate this circuit – Schematic created using CircuitLab Here ...
2
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1answer
52 views

Array of 4x7 Segment displays using demultiplexer. Need PNP transistors!

My first post here! I'm that most dangerous of EE-wannabes—a software guy with theoretical knowledge: V=IR, and transistors come in two flavours: "NPN" (1=On) and "...
-2
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1answer
101 views

I want to create a custom LED segment display. What do I need to study? [closed]

I want to create and then order a small run of a customized mass-produced LED segment displays for an art project. They will use PWM. It is not much more complex or detailed than a 7 or 16-segment ...
0
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0answers
30 views

How to assign pins of Altera Cyclone II to 7 segment?

I am quite new to FPGA and I want to design a 1-digit counter on a 7-segment on an Altera development board. What I have done so far was to schematically design a bcd to 7-segment decoder in Quartus ...
0
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1answer
44 views

how to determine resistor value calculation for common anode 7-segment display multiplexed

Resistor is required to limit the current flow through the LED since otherwise so much current will pass through that power dissipation shall destroy the LED in less than a second. For nonmultiplexed ...
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3answers
155 views

Driving large common anode 7 seg LED with NPN transistor and arduino, worked but is it the right way?

I'm newbie, the circuit designed myself for driving large LED worked but I'm not sure is there better ways? I have only NPN transistors and common anode 7 segment display. Thank you.
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0answers
36 views

How do I use the CD4026 IC with a multiplexed 7-segment display?

I have 2 pcs. of 3 digit multiplexed 7-seg display (ELT-511SURWA) and 6 pcs of CD3026. I am building a frequency counter (CD4060 + crystal as timebase). I have considered using 6x UDN2983 + CD4017 + ...
3
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1answer
100 views

Display Double Digit Numbers on 2 seven segment displays

I'm making an Arithmetic Logic Unit(ALU) for an assignment and I'm on a point. So according to my circuit design on the link shared below, I am able to output 1 digit of my alu. It is a 4 bit ALU so ...
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2answers
100 views

Why can a 74HC595 drive 8 LEDs?

I don't understand, I have seen many people use the 74HC595 to drive 5V across 8 5mm green LEDs via 220Ohm resistors at the same time, whereas the datasheet says that the maximum Vcc current is 70mA. ...
0
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1answer
84 views

NPN or PNP for multiplex seven segment display?

I want to put three multiplexed seven segment displays on a pcb module which then will be connected to another board through a 1x12 Pin header housing an ATMega (so assume in the following that Pin 11 ...
1
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2answers
73 views

LED radio display - How to control multiple segments at a time?

I have a display from an old radio (I think it was a Watson). Now, there are different wires connected to it: Let's call the first two A and B and one of the others (it seems to be not so important ...
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1answer
66 views

converting an analogue signal to be viewed on a 7 segment display

How do I convert an analogue signal to a digital signal and display it on 7 segment LED's. This must be done without using any programmable micro-controllers. It's for a school project. The analogue ...
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1answer
78 views

Arduino based clock with 4 pieces 4" 7 Segment LED Displays

I was going through multiple tutorials on how to create an Arduino clock with 7 segment displays. I planned to build one and purchased 4 large (4 inches) 7 segment 1 digit displays. The displays run ...
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2answers
78 views

Using 7-Segment Display on pic18f

I want to show a decimal number between 0-99 on 7-segment display by using 2 push buttons. These buttons will be used for incrementing and decrementing the number on display. I'm using pic18f assembly ...
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2answers
49 views

MAX7221 experiencing 40C temperature rise above ambient

Each MAX7221 (2) in my current design is getting very hot. I used the FLIR One to get a general measurement. I observed a 40C rise above ambient. I'm not sure what the root cause is. Perhaps ...
2
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2answers
67 views

BCD to 7 Segment is producing too little voltage

I am trying to use a BCD to 7 segment decoder to power my 7 segment display. This is the decoder I'm using (http://www.mouser.com/ProductDetail/Texas-Instruments/SN74LS47N/?qs=...
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3answers
147 views

Increase voltage from 5 to 12V to deactivate a display

I'm developing a timer based on this project: Digital Stop Watch with ATmega8 by Avinash Gupta (I cant put the link, because my reputation is too low) Original schematic: At first, I made the same ...
0
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4answers
103 views

Can this shift-register circuit be simplified?

I've created a circuit using a shift register to drive a 7-segment display which is all controlled by an Arduino Uno. The circuit appears to work fine, I have a sketch running which simply counts ...
0
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1answer
70 views

0.56inch 7segment display failure

I am Nikhil from India, working as an embedded programmer. I made half inch 7segment display based digital clock. But after few months few 7segment displays got damaged. I got same complaints in many ...
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1answer
66 views

Using a PAL for a seven segment display

I know next to nothing about PAL. I was wondering how one goes about programming a PAL (an old TIBPAL 16L8-25CN in my case) to drive a seven segment display, sort of like a HEF4511B. Right now I just ...
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2answers
89 views

VHDL: How does one assign custom values to identifiers of an enumerated type?

For a design with seven segment displays, it will be easier in modelsim simulation if one can see the actual display value going into the seven segment display e.g hexadecimal D which is "1000010" in ...
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1answer
96 views

What is the pin to light up colon in Basys 2?

I am trying to make a clock in a Basys2 board but I can't find in documentation the pin to light up the colon of the 7segment display. Where is it?
0
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1answer
74 views

Comparator and 7 segment display

I am trying to make a 7 segment display that displays the symbol <, > or = depending if a > b or a=b or a < b by using the output of a comparator(7 outputs from the comparator according to the ...
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2answers
47 views

Discrete Logic with Seven Segment Displays Problem

As a small project, I decided to make this circuit from Gadgetronix. However after wiring it, the display is stuck on 20 and when I activate the pushbutton, the 0 (display of IC2) just dims, and when ...
2
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1answer
89 views

FSM 4x7 segment displays Verilog

I got problem getting around Verilog. I am trying to create a FSM that displays numbers on one of the displays and on the next state to display a string. I did make the string to be displayed ...
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1answer
121 views

How do digital watches use so little power (and how do I do that?) [duplicate]

The title of the question is pretty self-explanatory. I did a quick back-of-the-envelope calculation for my own digital calculator watch (the Casio CA-53W for those who are interested). The battery ...
0
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2answers
70 views

How would I create this kind of circuit?

I'm just starting out with electronics, this should explain why my "schematic" is so readable. I'll attach it and explain further. I know how to create a simple circuit with the main slide switch and ...
4
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3answers
207 views

Is the there an intended PCB layout for the MAX7219/MAX7221 I'm missing?

The ordering of the segment pins (14-17, 20-23) on the MAX7219/MAX7221 common-cathode LED display driver is unusual, to say the least: The order of these pins is similar, but not identical, to the ...
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2answers
78 views

How to power a big high voltage 7-segment array with minimum parts, without frying my wimpy power supply?

I am trying to design a clock with a big 8-digit 7-segment display formed by about 250 LEDs, but with a power draw limit of 1A from a 5V USB phone charger. Each stroke is four LEDs in series and ...
0
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1answer
356 views

hexadecimal seven segment display verilog

I have a 4 bit output number as output. How can it be seen on seven segment display as hexadecimal number? I'm new and mentioning verilog. case example: ...
3
votes
1answer
132 views

How to “unground” a low state of a not gate

I have a seven segment display(LTS4680AE) and the anode of each segment keeps getting grounded. So I basically have a 4 bit adder which adds two 4 bit numbers and produces a 4 bit output. This output ...
0
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1answer
49 views

Voltage to segments on 7 segment display?

I am thinking of purchasing an LTS4680 seven segment display for one of my projects.Here is the datasheetdatasheet:http://www.icpdf.com/icpdf_datasheet_7_datasheet/LTS4680AE_pdf_1732299/...
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3answers
514 views

How to display a double digit decimal value on a seven segment display?

I recently finished a 4 bit adder project and I wanted to "extend" it.Right now,the output is represented by 4 led's(1 for each bit).I want to display the answer as a decimal in a seven segment ...
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votes
3answers
135 views

Designing logic for 7-segment display [closed]

I want to design the logic of a 7-segment display driver. As for the specs, I want it to have 4 inputs coding the binary value of numers 0-9 and 8 outputs for the display. I am not really sure where ...
0
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1answer
81 views

7 segment LED display not working when using common pin as cathode?

I am trying to wire up a 7 segment LED display but when I connect the common pin to ground and the LED pins to V+ the display doesn't work. However when I use the common pin as an anode and connect it ...
0
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2answers
737 views

4 Digit 7 segment display LED missing one light (on all four digits) [closed]

Hi I ordered online a voltage meter and got this tiny cute little fast refreshing pretty darn precise reliable meter. HOWEVER I am missing on all four digits the left lower vertical light piece. What ...
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votes
1answer
103 views

How can i connect 9 7segments to a 3x4 keypad using only diodes making each 7segment displays only one number? [closed]

I want to make each button in the keypad to display one number using only diodes without using any decoders or ic. thanks in advance
0
votes
1answer
59 views

How to Separate 7 segment power supply

I'm trying to drive a multiplexing double digit 7 segment (5261AS) using Arduino and two shift registers (74595) I need to separate power supply for the 7 segment to avoid overloading current from the ...
1
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0answers
31 views

How to control four 10-pin 7 segment display [duplicate]

I'm a student trying to make a device for our research project so I'm quite (if not entirely) new to electronics. I'm planning to make a 4 digit display using four 7seg display using arduino and each ...
0
votes
1answer
201 views

How to convert BCD to multi-digit 7-segment?

I have a BCD input in the form of 8 wires (eight bit number, up to 511 decimal) and I want to display it on a seven segment display. I have found a product which has 4 1/2 digits and a converter, but ...
0
votes
1answer
155 views

Problem with 7-segment display: dimly lit when off

I'm driving two large seven-segment displays using two shift registers (74HC595). The displays have a forward voltage of 12V and a max forward current of 20mA. I'm feeding data and 5V of power to the ...
0
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2answers
58 views

Appropriate Brightness for LED Displays

This may be a question strongly depending on application and opinion, but I'll give it a try. I am designing some controls for an industrial application, including cap touch buttons and LED 7-segment ...
0
votes
3answers
171 views

Driving 2inch 7segment display using pic microcontroller

I want to drive 2 inch 7segment display(common anode) using pic microcontroller. The forward voltage of segment is around 7v. The emitter of the pnp transistor is connected to the12v power supply. ...
1
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1answer
123 views

Using a LS248 7-segment driver, but segments are dim. Can't figure out why

I'm building a project where I want to use two double-digit 7-segment-LED displays (green, common cathode). From what I've read, a shift register wouldn't be able to source enough current, so I ...
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2answers
623 views

Driving two large 7-segment displays using Arduino and shift registers

I recently started a project in which I want to control two 7-segment LED displays using two shift registers (74HC595) and my Arduino. I thought I had the basic ideas mastered, but I ran into some ...
0
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1answer
79 views

7 segment display orientation problem

So i am completely new on this topic. i have a problem which looks something like this. i have a light which is designed with a 7 segment display which gives the reading of various parameters . the ...
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2answers
2k views

Proteus ISIS Fast simulation

I want to display my output on 3 seven segment displays, I am doing that by serially switching them on and off. I have taken some help from here : http://www.avr-tutorials.com/projects/atmega16-based-...
0
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1answer
978 views

7-segment blue LED display at 3.3V

I'm driving a blue 7-segment LED display with a TI CD4026BE on a 3.3V circuit. I cannot find any data sheet for the display part. It has a common cathode pin layout and it's marked FJ5161AB on the ...
0
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4answers
369 views

4 digit 7 segment CC - all digits count the same number

Ultimately I'm looking to build something that's going to count revolutions as part of a guitar pick up winder. I've got a circuit hooked up with 4 x 4026 counters going into a 4 digit 7 segment ...
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1answer
383 views

Design a Decoder using Logic Gates to display letters on a 7-Segment Display

The task I got is to design a similar circuit to a standard BCD to 7-Segment decoder, except only using Logic Gates and to display a eight letter character word, for example: SHELFLES As I have ...