“beats” the beats not only sound, but light pulses. In his scheme includes two transistor of different conductivity. The excitation amplifier is implemented by using positive feedback through the capacitor C1. The pulse repetition frequency — from 40 to 210 per minute — adjust the variable resistor R2. The amplitude — adjusted with resistor R5.
The transistor T1 of the type МП37, T2 — МП39. The dependence of the selectable resistance of the variable resistor R2 of the rotation angle of the engine must be linear. The resistance of the voice coil of the loudspeaker is 8 Ohms.
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Sandpaper glued to the plate, to help clean the soldering tip on the scale and layers of soot. And put on the skin of the pieces of tin and rosin help both obludit sting. Y. Zhdanov
CUTTER OF HOOP
Loves to embroider or cross stitch is used for the tensioning of the fabric an ingenious device — the Hoop: two wooden or plastic rings, one of which together with the tissue fits snugly...