The scheme is, in principle, a standard. Zener diode VD1, you will not believe the voltage stabilizes. A transistor VT1 amplifies the output current. FU1 Fuse 1A serves to short-circuit protection. "Chip" scheme -a powerful application of the germanium transistor. Need to use the nominal germanium transistor, rather than silicon, since the voltage drop at the pn junction "base -emitter" in the transistor on a germanium crystal only 0.3 V, while the silicon -0.7 V, which in this situation is already critical . Transistor should definitely put on a radiator, since it is strongly heated. To check that there is enough of a radiator, turn on the lamp to a fully charged battery and wait 10-15 minutes. Then touch the radiator or the body of the transistor -if the finger can not "straining" hold -that the radiator will be enough if the "burn" -that need more radiator. Instead D814D can apply any other diode with the same strain of stabilization and less power dissipation. Transistor can supply any of the series P216-P217. Any resistor at 0,125 watts or more.
Here`s my version of the stabilizer design. I put it in a jar of aluminum under filmstrips, pre-insulated her inside. Inside we put a transistor with a radiator, which is bolted board stabilizer. Track I applied varnish, then etched and soldered straight over all the details. The result here is a "surface mount for the poor": -. Keep in mind that the body of the transistor -is manifold, so do not close it! Fuse I put on pads borrowed from old power supply for your computer. From there you can take the radiator and if like the photo, you do not -just drank right size plate and drill holes conclusions. In the lid of the jar I made holes for cables. As applied SHVPT wire 2x0, 35, who just fit these goals. Most importantly, do not forget all the good seal!
And so I wish everybody a successful assembly. Any leave your comments below.
Material steal: http://radiostroi. ru/