This is a seven segment counter that is founded on the counter ICCD 4033. The seven segment counter circuit can be used with a variety of circuits where the counter being displaying the progress adds some more value.
The CD 4033 is triggered IC NE 555 which is wired as an astable multi-vibrator. It is also displayed by the 7 segment LED display LT543. Switch labeled S1 is the one used to initiate counting. Diode D1 is used to prevent risk of inadvertent polarity reversal. There are several examples of the seven segment counter circuit the most common being the 0 to 9 display.
Seven segment displays is made up of 7 LEDs labeled ‘a’ through ‘g’. We can also display the digits from 0 to 9. There are two types of seven segment display known as Common anode and Common cathode.
In common anode types of display, anodes of all the 7 LEDs are tied together, while in the cathode type, we have all cathodes tied together. Resistors R1 to R7 are used as current limiting resistors. IC 7446 is a decoder/driver IC used in driving the seven segment display.
Working of common anode type of seven segment counter display is very simple. The IC2 (7490) BCD output advances by one bit in every second. The IC1 (7446) decodes this BCD output to correspond the seven segment type. This will drive the exhibit to indicate the corresponding number.
Points to note
- Assembling the circuit on a perf board is easy.
- 5v DC is used for powering the circuit.
- The clock can be set to the pin number 14 of IC2.
- D1 have to be a 7 segment common anode display.
- All IC s also have to be mounted on holders.