Using high voltage transistors can be designed a DC power supply that can provide a supply voltage between 10 and 300 volts which can be adjusted with the potentiometer P1.
A symmetrical power supply, can be designed using this circuit diagram. This symmetrical power supply is designed using a simple operational amplifier and some classic electronic components
A simple 12 volts voltage regulator car adapter circuit can be used to power your electronic devices from your car can be designed using few common electronic components .
