This is a high quality power supply with a continuously variable regulated output voltage adjustable from 0 and 30V DC. Its design is based on three 741 Integrated Circuits and incorporates an electronic output current limiter that effectively limits the output current from 0 to a maximum of 2.5A. This makes this power supply an indispensable tool in a laboratory as it allows to limit the current to the typical maximum that a circuit under test may require, therefore protecting the circuit from any damage that might be caused if something goes wrong.
The circuit also incorporates an overload indicator LED so that it is immediately visible that the circuit is exceeding the preset limit. Also incorporated is a instant shut-down feature so that when power is removed from the unit, the output of the power supply disappears virtually instantaneously and therefore prevents any spurious effects that are common in power supplies. This can be an asset when doing test or experimental work since it allows one to kill the supply and perform circuit modifications without having to wait first for the power supply's internal capacitor to slowly discharge.