His good-natured face is loved by children. Especially good “eye” — a bright, green and… crafty. The cat all the time “wink” — his pupils are then compressed, then expand.
The “eye” of a cat — electro-optical indicators (EDP) 6Е5С that are used in radio receivers to indicate accuracy of tuning. The relaxation generator on neon lamp MH-3 (L1) controls the operation of the two EDP (scheme). The capacitor C1 is periodically charged via the resistors R1 and R2 until the ignition voltage of the neon from the pampas, to be discharged through it. With potentiometer R2 the oscillation amplitude of the generator 9 To act on the control grid of lamps L2 and LZ. Filament of incandescent lamps connected in series and fed directly from the mains AC voltage of 220 V through a capacitor C2. The rest of the homonymous electrodes of the two lamps are connected in parallel.
If the voltage on the grids of electron-optical indicators for zero, dark sector on their screens maximized. Negative voltage — dark sector is shrinking.
Resistor R4 provides a constant negative bias of 9 volts on the grids 6ESC. When the relaxer receives positive pulses with an amplitude of 9 V, the total potential of the grids becomes different to zero. Lamps open, dark sector expands to the limit. Periodically repeating this process provides the effect of “flashing” eyes.
AC voltage is rectified by diode D1 and is smoothed by the filter R6C3. The resistor R7 is restrictive.
Circuit diagram of “e-cat”:
R2 is a variable resistor SPO; C1, C3 — C50-6, C2 — MBGP 250, D1 — tens of Hz-24, Д7Ж, Д226Б.
When creating a schema should break the circuit at point “a”. Especially carefully it is necessary to choose the damping capacity of the capacitor C2 to the voltage of the incandescent lamps L2, LZ not go beyond 5,7 — 6,9 V. With resistors R6, R7 of the voltage on the anode bus set to 200 V, and resistor R4 — 9 In the grids L2, LZ. The selection of capacitor C1 to receive the desired frequency. Its amplitude controlled by a valve voltmeter or oscilloscope.
Then restore the circuit at point “a”.
The scheme is collected in a wooden case. On its front panel bonded to faux fur and strengthen the mask of a cat, made of papier-mache. You can buy in the store.