This Lab power supply I have designed, it's full protected.
It's a good laboratory instrument for those who want to begin but also for professional use.
One transistor is used to activate a rele that break the output connection as soon as the current is above the preset limit . The other transistor is used to activate a piezo buzzer that will beep for a while before breaking the contact.
This supply is capable of 5 A . The lm338k should be mounted on appropriate heathsink, possibly with a fan.
This project is part of a great project : a complete laboratory instrument set , equiped with low frequency oscillator, audio amplifier, frequencymeter and Iron temperature control circuit, all in one box.
Enjoy
Alfredo
