Circuit Documentation

Summary

This circuit consists of a DC power source, multiple resistors, red LEDs, 74HC21 logic gates, a 7-segment display, and DIP switches. The circuit is designed to control the LEDs and the 7-segment display using the 74HC21 logic gates and DIP switches.

Component List

1. DC Power Source

   • Pins: Ground, Positive
   • Description: Provides the necessary power for the circuit.
   • Properties: None

2. Resistor

   • Pins: pin1, pin2
   • Description: Limits the current flowing through the circuit.
   • Properties:
     • Resistance: 1000 Ohms

3. LED: Two Pin (red)

   • Pins: cathode, anode
   • Description: Emits red light when current flows through it.
   • Properties: None

4. 7-segment Display

   • Pins: A, B, C, D, E, F, G, COM, dot
   • Description: Displays numerical digits using seven segments.
   • Properties: None

5. 74HC21 Logic Gate

   • Pins: A1, B1, NC, C1, D1, Y1, GND, VCC, D2, C2, B2, A2, Y2
   • Description: Dual 4-input AND gate.
   • Properties: None

6. DIP Switch 4 Position

   • Pins: 1, 2, 3, 4, 5, 6, 7, 8
   • Description: Allows manual switching of connections.
   • Properties: None

Wiring Details

DC Power Source

• Positive is connected to:

  • Anode of all LEDs
  • COM pin of the 7-segment display
  • VCC pin of the 74HC21 logic gate

• Ground is connected to:

  • A1 pin of the 74HC21 logic gate
  • pin2 of multiple resistors

Resistor

• Resistor 1

  • pin1 is connected to the cathode of an LED.
  • pin2 is connected to the C1 pin of the 74HC21 logic gate.

• Resistor 2

  • pin1 is connected to the cathode of an LED.
  • pin2 is connected to the D1 pin of the 74HC21 logic gate.

• Resistor 3

  • pin1 is connected to the cathode of an LED.
  • pin2 is connected to the Y1 pin of the 74HC21 logic gate.

• Resistor 4

  • pin1 is connected to the cathode of an LED.
  • pin2 is connected to the GND pin of the 74HC21 logic gate.

• Resistor 5

  • pin1 is connected to the NC pin of the 74HC21 logic gate.
  • pin2 is connected to the 1 pin of the DIP switch.

• Resistor 6

  • pin1 is connected to the B2 pin of the 74HC21 logic gate.
  • pin2 is connected to the 2 pin of the DIP switch.

• Resistor 7

  • pin1 is connected to the A2 pin of the 74HC21 logic gate.
  • pin2 is connected to the 3 pin of the DIP switch.

• Resistor 8

  • pin1 is connected to the Y2 pin of the 74HC21 logic gate.
  • pin2 is connected to the 4 pin of the DIP switch.

• Resistor 9

  • pin1 is connected to the C2 pin of the 74HC21 logic gate.
  • pin2 is connected to the 4 pin of the DIP switch.

• Resistor 10

  • pin1 is connected to the NC pin of the 74HC21 logic gate.
  • pin2 is connected to the 3 pin of the DIP switch.

• Resistor 11

  • pin1 is connected to the B2 pin of the 74HC21 logic gate.
  • pin2 is connected to the 2 pin of the DIP switch.

• Resistor 12

  • pin1 is connected to the A2 pin of the 74HC21 logic gate.
  • pin2 is connected to the 1 pin of the DIP switch.

LED: Two Pin (red)

• LED 1

  • cathode is connected to pin1 of a resistor.
  • anode is connected to the Positive pin of the DC power source.

• LED 2

  • cathode is connected to pin1 of a resistor.
  • anode is connected to the Positive pin of the DC power source.

• LED 3

  • cathode is connected to pin1 of a resistor.
  • anode is connected to the Positive pin of the DC power source.

• LED 4

  • cathode is connected to pin1 of a resistor.
  • anode is connected to the Positive pin of the DC power source.

7-segment Display

• A is connected to the C1 pin of the 74HC21 logic gate.
• B is connected to the D1 pin of the 74HC21 logic gate.
• C is connected to the B1 pin of the 74HC21 logic gate.
• D is connected to the A1 pin of the 74HC21 logic gate.
• E is connected to the GND pin of the 74HC21 logic gate.
• F is connected to the NC pin of the 74HC21 logic gate.
• G is connected to the B1 pin of the 74HC21 logic gate.
• COM is connected to the Positive pin of the DC power source.
• dot is connected to the NC pin of the 74HC21 logic gate.

74HC21 Logic Gate

• A1 is connected to the Ground pin of the DC power source.
• B1 is connected to the C pin of the 7-segment display.
• C1 is connected to pin2 of a resistor.
• D1 is connected to pin2 of a resistor.
• Y1 is connected to pin2 of a resistor.
• GND is connected to pin2 of a resistor.
• VCC is connected to the Positive pin of the DC power source.
• D2 is connected to the DIP switch.
• C2 is connected to pin1 of a resistor.
• B2 is connected to pin1 of a resistor.
• A2 is connected to pin1 of a resistor.
• Y2 is connected to pin1 of a resistor.

DIP Switch 4 Position

• 1 is connected to pin1 of a resistor.
• 2 is connected to pin1 of a resistor.
• 3 is connected to pin1 of a resistor.
• 4 is connected to pin1 of a resistor.

Code

No code is provided for this circuit.