Circuit description:

  • We have studied the circuit diagram of Good Morning Alarm in the previous article. Here, we will learn to assemble this circuit.
  • A specially designed PCB is used to make this circuit. Such PCBs are called special purpose PCBs. No wiring is needed with such PCB. We just have to place the components at the designated place and solder them properly on the reverse side. On the solder side, there are conducting tracks inscribed instead of wire connections. This makes the circuit neat, crisp and less cumbersome.



  1. First and foremost exercise is component identification. For this, we will prepare Component Identification Data (CID) for the components of the circuit. Please refer to blogs (Sign language of circuit diagrams, Resistor: Value reading) for ease in doing CID.

  1. Insert the components on the required place as per the CID. The component side of the PCB has values mentioned on it.
  2. R1, R2, and LDR have no polarity and can be mounted in any direction. Turn the PCB. Bend the component leads to prevent them from falling.

  1. Mount transistor BC548 and BC558 as per labeling on the PCB. Please check the direction of the transistors before mounting.

  1. Take out your tool kit, heat up your soldering iron for making the connections (Soldering: The real action).

  1. Cut the extra lead of the component after soldering.

  1. Now, connect the buzzer to the circuit. Prepare the wires of buzzer (cut, peel, wrap) and solder them in the circuit as per the polarity (Red: +VE; Black: -VE).
  2. The circuit is energized by 9V battery. Solder the snap to the circuit as shown below.

  1. The connections are complete. Check the solder side of the PCB and make sure that all the leads are soldered. Now it is time to energies the circuit. Insert the battery in the snap and test the circuit.
  2. Thus, this circuit can be kept in a place in your room where the sun light falls early in the morning. When sunlight falls on LDR, it is activated and you wake up to a beautiful tune.
Stay tuned for more such circuits.