Here is the Universal PCB for PSU with 78XX Family regulators.Many DIY projects require a small Power Supply. The 78XX family is ideally suited for this job, and with this little PCB you can easily build small Power Supplies for virtually every application. The circuit is very simple.source

Sometimes you need a simple negative power supply. The best example is the contrast PSU for common small LCD device. Building -5V from a battery or a wallmart supply isn’t really easy.Here is a simple circuit that is able to provide -5V, -12V, -15V. The circuit used the MAX 764/765/766 series. You can simply change the chip to provide the good output.

The MAX764/MAX765/MAX766 inverting switching regulators are highly efficient over a wide range of load currents, delivering up to 1.5W. A unique, current-limited, pulse-frequency-modulated (PFM) control scheme combines the benefits of traditional PFM converters with the benefits of pulse-width-modulated (PWM) converters.

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Here is an efficient 4-stage stabilised power supply unit for testing electronic circuits. It provides well regulated and stabilised output, which is essential for most electronic circuits to give proper results. The circuit provides an audio- visual indication if there is a short circuit in the PCB under test, so the power supply to the circuit ‘under test’ can be cut-off immediately to save the valuable components from damage.source

15V dual Power Supply for Preamplifier based on 7815 and 7915 regulator.This circuit will not work with external DC power supplies.The rectifier is a “full-wave voltage doubler” type, and with an input of 16VAC will provide about +/-20V DC at a current of 100mAsource

A power supply that is suitable for most amps of 60W output. Can be adapted or modified to other voltages for more or less power.A power supply suitable for use with the 60W amplifier presented in the predeeding project is perfectly simple, and no great skill is required to build (or design) one. source