IMITATOR OF SOUNDS“Development, published in the journal “modelist-Konstruktor”, make ourselves photoelectron shooting. Works flawlessly. It is a pity that the sounds in the scheme is not provided. Help!”. The fraction of machine-gun fire, screeching min, heavy bass bombs… Simulates a similar sound picture of the fight is pretty simple device, made only three transistors.

As can be seen from the circuit diagram, simulator sounds of battle consists of a self-excited pulse generator — multivibrator on VT1 and VT2 transistors, an amplifier (semiconductor triode VT3) and the dynamic head of BA1. And choose sound effects the user, by pressing certain control buttons.
To simplify the design uses a single shared generator mode of operation which changes the corresponding switching. In the “machine gun” this multivibrator receives power directly from the battery GB1 via the switches S4 (it includes the simulator) and the S1, which (through the contacts of S1.2, S1.3) in parallel with the capacitors C5, C7, connects the relatively large capacitance of C3 and C6, which provides a “place” with some frequency “shots”. If desired, adjusting the value of capacitors C3 and C6, to change the frequency with which “scribbling machine gun.” The amount of current of the transistor VТЗ indicated in the diagram, set the selection of resistor R5.
When simulating the passage of the mine power is supplied from the pre-charged capacitor C1 when the movable contact of the group S2.1 switch is thrown to the right position according to the diagram. At the same time in the shoulder of the multivibrator group S2.2 includes the capacitor C4. As the discharge of capacitor C1 the voltage at the multivibrator gradually decreases, with increasing generated frequency and there is a sound like the screeching of the flying mines.
Schematic and circuit Board device simulate sounds.
Schematic and circuit Board device simulate sounds.
Circuit diagram and circuit Board of the device simulate sounds.
Organization of power supply of the multivibrator in the “rocket” is similar — from the capacitor C2 through the switch s3. In this case, in the shoulders of the multivibrator employs only capacitors C5 and C7. Sound starting with low notes, gradually increased to very high and sort of goes away.
The signals simulated are amplified by the cascade on the VT3 transistor included in the circuit with common emitter. His load is the dynamic head of BA1 in the collector circuit of the transformer T1.
The power supply simulator is a battery, “Emery”, or two elements 3336, connected in series. It is possible to use a network block (adapter). As switches S1-S3 is better to use buttons or toggle switches with self-return to its original position. As S1 fit range switch stab type from the portable radio. Automatic return to open position here will be provided if the switch knob to provide a spiral spring.
The mounting plate of the simulator is performed from foil fiberglass. To its “printed” pads soldered the appropriate electrolytic capacitors K50-6 or MBM (C4), KLS (C1-ene, C5—C8), resistors (all of them — like MINTS, of a power not exceeding 0.5 W) and other elements of an electrical circuit.
It is possible to replace used parts in their counterparts. In particular, it is indicated on the circuit diagram transistors will fit other series МП39-МП42А as well (only all at once) MP35-МП38А structure p-R-p. But in the latter case it would have to be reversed the polarity of the power supply and electrolytic capacitors.
The transformer T1 output, from the radio of type “Selga-404”. Dynamic head — 0,1 GD-8 or another with the impedance of the voice coil 8-10 Ohm.
Controls can be placed in the body of the simulator or the remote panel connected to the charge harness from flexible stranded wire in vinyl insulation. Dynamic head is mounted on the front panel, where it drilled holes with a diameter of 2-3 mm (wizard and “sound”, located in front of the diffuser).
Correctly assembled device starts working immediately upon power up.

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