Category: power supply

Various power supply-based project is already posted on bestengineeringprojects.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 circuits and is very important for electronics geeks or hobbyists. The circuit presented here is of a 5-stage stabilized power supply unit and it provides well-regulated output, which is essential for most electronics circuits for proper results. Another advantage of the circuit stabilized power supply with short-circuit indication has it provides an audio-visual indication…

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This is a complete short-proof variable power supply circuit that gives 3V, 5V, 6V, 9V, 12V, and 15V output voltage and a maximum output current of 700mA. The unique feature of the circuit short proof variable power supply is that the power dissipated is reduced to a negligible level during short-circuit or overload conditions. In conventional power supplies, the maximum rated current continuously flows through the load under overload conditions. This may damage the power supply and the load. Working of Short Proof Variable Power Supply Circuit The circuit short-proof variable…

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Many Inverter Circuits have already been posted on many other websites. The inverter circuit “Crystal Controlled Inverter” presented here provides a stable output frequency even when there is a change in the DC voltage applied to the inverter. This stable output of the Crystal control Inverter is obtained from the 3.2786 MHZ crystal (XTAL1). You can also make your 3000W inverter using a microcontroller. Circuit Description of Crystal Controlled Inverter. The Inverter circuit “Crystal Controlled Inverter” is built around popular flip flop IC MM 5369 (IC1) followed by a few…

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We are aware that when the line voltage becomes more than 250 volts and less than 160 volts, it can damage our TV sets, refrigerators, etc. Hence, we use voltage stabilizers which are costly. The circuit Automatic Cut-off Power Supply described here is low-cost. The assembling cost comes to around $1 only. If the voltage exceeds the mentioned range it automatically cuts off the supply so that the life of the TV set and other devices can be extended. Circuit Description of Automatic Cut off Power Supply The common point of…

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Fuse protection for electronics circuits seems to be an outmoded idea, for there are circuits (in computers etc) that consume high currents initially at a lower stable value. In case high-rated fuses are employed in such equipment to accommodate the initial surge current, it defeats the very purpose of protection. Slow-blow fuses often turn out to be too slow while quick-action fuses may blow out at the mere hint of a surge. An electronics fuse circuit of the kind described here provides an ideal solution in such cases. An electronic…

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For op-amp circuits, the power supply must provide positive and negative voltages. Here is a simple circuit “Adjustable Bipolar Voltage Regulator” which gives a regulated ± 1.2V to ±2oV supply. ICs LM317K (IC1) and LM337K (IC2) are used here as positive and negative regulators respectively. Circuit Description of Adjustable Bipolar Voltage Regulator using LM337 The circuit diagram of the adjustable bipolar voltage regulator using LM337 is shown in figure 1, and is designed using two positive and negative adjustable voltage regulator IC, a step-down transformer, a bridge rectifier, and a…

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The usual method of using a 9V battery for backup in digital clocks, though common, is not very desirable for many reasons. The cost of the battery and the very short life are some of them. Circuit Description of Power Back-up Circuit for Digital Clock The circuit described here is a Power backup Circuit for a digital clock and it enables us to get the required 9V from just two penlight cells. Initially one has to invest in this circuit power backup for a digital clock, in the long run,…

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This Self Switching Off Power Supply Circuit switches itself off when no current is drawn by the load. When a load current flows, the potential difference across diode D6 is sufficient to cause diode D7 = and transistor T2 to conduct. Transistor T1 is then switched on and the relay is energized. If you are new to relay drive circuits then you can watch this making video on How to make relay switching circuits. When the load current ceases, T2 switches off. The base current of T1 then charges capacitor…

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