A Simple 0-9 Counter Circuit with 7-Segment Display is a simple digital setup that shows the numbers from 0 to 9 on a 7-segment display.
This kind of circuit is often used in things like digital counters, clocks and measuring devices where showing numbers is important.
The main parts of this circuit are a 7490 Decade Counter Integrated Circuit IC and a 7446 Binary Coded Decimal (BCD) to 7-segment Decoder/Driver IC which work together with a common anode 7-segment display.
In a common anode setup all the positive sides of the seven LEDs are connected while in a common cathode setup all the negative sides are linked.
The circuit gets its power from a 5V direct current DC supply, which runs the whole system.
Circuit Working:
Parts List:
| Component | Quantity |
|---|---|
| Resistor 1/4 watt 220Ω | 7 |
| IC 7446 | 1 |
| IC 7490 | 1 |
| 7-Segment Common Anode Display | 1 |
The IC 7490 is a decade counter that can count from 0 to 9.
It works by taking in the clock input pulse and then gives an output in Binary Coded Decimal (BCD) format.
The outputs from the IC 7490 go to the 7446 IC for further processing.
The 7446 ICs job is to change the BCD input from the IC 7490 into signals that will light up the 7-segment display.
To connect everything the outputs from the 7446 IC are attached to the different segments of the display using current limiting resistors.
A common anode 7-segment display is used to show the numbers from 0 to 9.
The display connects to the 7446 ICs output through 220 ohm resistors R1 to R7.
These resistors help control the current going to the 7-segment display.
The clock input pulse signal is sent to pin 14 of IC2 and each time the 7490 counter receives a pulse, it increases its count by one.
Formulas with Calculations:
The formulas with calculations for Simple 0-9 Counter Circuit with 7-Segment Display are mentioned below for better understanding:
The resistors R1 to R7 help control the amount of current going to the 7-segment display.
We figure out their values by using ohms Law:
R = (V – Vf) / I
where,
- V is 5V Power supply voltage
- Vf is 2V Forward voltage drop per segment
- I is 15mA current for LED segments
R = (5V – 2V) / 15mA = 3V / 0.015A = 200Ω
A standard value of 220Ω is used to ensure the segments do not exceed their current ratings.
How to Build:
To build a Simple 0-9 Counter Circuit with 7-Segment Display follow the below steps:
- Gather all the components as mentioned in the above circuit diagram
- Connect pin 1 of IC2 7490 to pin 12 of IC2 7490 and pin 7 of IC1 7446
- Connect pin 2,3,6,7,10 of IC2 to GND
- Connect pin 8 of IC2 to pin 2 of IC1
- Connect pin 9 of IC2 to pin 1 of IC1
- Connect pin 11of IC2 to pin 6 of IC1.
- Connect pin 5 of IC2 to positive supply of +5V DC.
- Connect pin 3 , 4, 5, and 16 of IC1 to positive supply of +5V DC.
- Connect pin 8 of IC1 to GND.
- Connect pin 13 of IC1 to display pin 7(a) through resistor R3.
- Connect pin 12 of IC1 to display pin 6(b) through resistor R4.
- Connect pin 11 of IC1 to display pin 4(c) through resistor R5.
- Connect pin 10 of IC1 to display pin 2(d) through resistor R6.
- Connect pin 9 of IC1 to display pin 1(e) through resistor R7.
- Connect pin 15 of IC1 to display pin 9(f) through resistor R1.
- Connect pin 14 of IC1 to display pin 10(g) through resistor R2.
- Connect 8(CA) and 3(CA) of display pin to positive supply of +5V
- Connect pin 14 of IC2 to clock pulse input.
Conclusion:
This Simple 0-9 Counter Circuit with 7-Segment Display is a basic digital circuit that is commonly found in many different uses.
It shows how BCD counters, decoder/driver ICs and 7-segment displays work together.
If you make some changes it can count multiple digits track events or even function as a simple timer.
The 7446 decoder IC makes it easy to connect with a 7-segment display, which helps the circuit run smoothly and dependably.