The device is useful for a model fire truck and a guard system. The intervals between the signals and their duration is controlled by changing values of electrolytic capacitors C1, C3, fixed resistors R2, R4 (see diagram). Sound effects you can Supplement the indicator light, replacing the resistor R3 with a bulb from a pocket lantern 2,5ВХ0,1A. Output transformer and speaker from any small-sized transistor radio.
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When pouring the boiling water from the kettle didn't fall cover, fabricated sheet metal a simple device that secures the lid in an inclined position of the kettle. C. DACKOW, Novovyatsk
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Mercury thermometer, as we know the fragile and the contained mercury is also very dangerous. So if there is no standard paper sheath for it that will help out a makeshift rubber tip....
