Various power supply based project is already posted in bestengineeringproject.com. Now, here is a stabilized power supply circuit with the facility of short-circuit indication. As we know that stabilized power supply is used for testing various electronics circuit and is very important for electronics geek or hobbyist. The circuit presented here is of 5-stage stabilized power supply unit and it provides well regulated output, which is essential for most electronics circuit for proper result. The another advantage of the circuit stabilized power supply with short-circuit indication has it provides an audio-visual indication if there is a short in test circuit, and also cut-off the power supply immediately in order to save the valuable components. The four regulated output (12v, 9v, 6v, and 5v) and an unregulated output (18v) is obtained at its output and is selected by switch SW2 (rotary switch). The output taken is indicated by an analogue voltmeter connected to the output rails as shown in circuit diagram.
Circuit description of stabilized power supply with short-circuit indication
The circuit of stabilized power supply unit utilized voltage regulated IC for regulated output and few other active as well as passive components for audio-visual indication of short-circuit. The input AC of 230V is stepped down using 9V-0-9V stepped down transformer and is further rectified using rectifier build using diode D1 to D2. The rectified output is further filtered by 1000 µF of capacitor C1 and given to the regulator through switch SW1 as shown in circuit diagram. The fixed regulated output of 12V, 9V, 6V and 5V is obtained from IC1 through IC4 respectively. This power supply circuit is useful for loads requiring up to 200mA current.
LED1 (bi-color LED) is used to indicate either fuse is intact or blown up. When power is available and fuse is intact both the halves (red and green) are effectively in parallel to output a yellowish light. In condition of fuse blown up, the green half goes off and only red light up to indicate.