This stabilized source can supply currents up to 700 mA and the output voltage is close to 15 V. a little less with the load. The power transistor must have a good heat radiator.
This circuit was obtained from an old American documentation, and practically any general-purpose transistor...
This circuit is intended for monitoring an environment. It fires a relay with a sound, but only if...
This circuit is from an old documentation, but perfectly current. In place of the battery, 2 or 4...