This circuit uses an LM317 regulator, chosen because of its built-in over-current and over-temperature protection. Its output is boosted up to 5A by the MJ2955 transistor. The output voltage is varied by adjusting VR1 potentiometer. Adjustable current limiting from 60mA to 5A is provided by op amp TL071 IC that is used as a comparator which monitors the voltage across the 0.1 Ohm current sensing resistors.
Build Accurate LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and reset function to make sure the readings are as accurate as possible ... [more]