Schematic Diagrams

Useful schematic and wiring diagrams. ✔ ✔ Enjoy electronic circuits, let your idea comes to hardware

voltage regulator

Mains Failure Alarm

This circuit was designed to produce an audible alarm when the mains power is interrupted. Such an alarm is essential for anyone whose livelihood depends on keeping perishable foodstuffs in cold storage. The circuit is powered by a 12-V mains adapter. LED D5 will light when the mains voltage is present. When the mains voltage […]

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Circuit Project: Solar Panel Voltage Regulator

Our energy-hungry and environmentally aware society has been slow to make good use of the sun’s “free” power. But now it’s finally taking off. Using the sun’s heat directly, for cooking and other applications, is already a common and popular technology in countries that have good weather. Hot-water panels are nowadays used in many parts […]

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LM78S40 5V to 15V Step-up Voltage Regulator

We can do a step-up conversion without using transformer. Using this circuit, a 5V DC source can be converted into 15V. Please note that there is no power gain here, as we cannot create energy from nothing, it means that we can leverage the voltage but the current will drop. This circuit can provide 15V […]


Switchable 6V, 9V, and 12V Linear Voltage Regulator

  We can build a multiple voltage power supply 6, 9, and 12V  (AC-DC Adapter) with the circuit shown in the following schematic diagram.  Not only provide multiple voltage output with single voltage supply, this circuit add the benefit of regulating the voltage for better stability. A transformer with rectifier diodes and filtering capacitor can […]


Linear Power Supply Circuit

A diode bridge, a step down transformer a linear regulator(U1) and some filtering capacitors can be used to build a Linear power supply. This circuit has some advantages such as this circuit has high output current and can give multiple output voltages easily. However it has some disadvantages like this is high standby losses, expensive […]


Low-Drop-Out (LDO) Low-Voltage Linear Regulator Using NCP2860 IC

This low drop out (LDO) voltage regulator need only few components, with very low noise and very low drop-out voltage. The circuit illustrated in the schematic diagram below gives a fixed 2.77 volt output, but this output voltage can be adjusted using two additional resistors. This circuit capable to supply 300 mA load from 3.0 […]

High Efficiency Switch Mode 3.3A 10A Regulator

This switch mode regulator circuit has higher current output than  our previous switch mode regulator, but it uses same controller IC. Up to 10A can be served by this switch mode regulator. The output of this regulator circuit is regulated at 3.3 volt, and the input range is 4-9Volt. The SHDN pin can be pulled […]


High Efficiency Switch Mode 3.3V 5A Step-Down Converter

This switch mode step-down converter has very good efficiency, up to 94% can be obtained. This switch mode regulator uses LTC1266-3.3 controller with external N-Channel power mosfet, and need only a 5uH inductor because it uses high frequency switching. Here is the schematic diagram of this switch mode step down converter circuit: To optimize efficiency, […]


Transformerless, Switch Mode Boost Regulator, A Step-Up Converter

Using this switch mode regulator circuit, you can get a stable 12 volt output (500mA) although you just have 4,3 – 10V power supply. You can even boost a 3.5V input to 12V if the load draws only 100 mA or less. This switch mode voltage regulator use LTC1266 IC chip from Linear Technology. Here […]


Transformerless Voltage Booster Circuit: A DC-DC Step-Up Switching Regulator Using Transistors

A DC-to-DC step-up converter is traditionally implemented using transformer, working by converting the DC voltage to AC Voltage, step-up it using transformer, then rectify and filter the transformer’s output to  get a higher DC voltage. Using a switching method, we can step-up a voltage without a transformer. We just need an inductor which is driven […]


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