Do it yourself - diagram of a multi-voice sound simulator.

 ╔═══════════════════ ═══════════════════╗
  ║Section: Do it yourself;                    ║
  ║Article:Multi-voice sound simulator;║
  ║Text: Vorozhkin Alexander.            ║
  ╚═══════════════════ ═══════════════════╝

 There are many known electronic devices,
  imitating, for example, the voices of birds and animals
  votives, the sounds of jumping steel
  ball and the whistle of an ancient steam locomotive. In one
  These devices use multi-groups
  vibrators interconnected, in other
  gikh - generators with self-excitation.
   In the proposed simulator, collected all
  go on one chip and transistor
  (Fig. 1), both options were used. In addition
  Moreover, the microcircuit in the simulator works...
  without power - pin 14 of the microcircuit to use
  GB1 is not connected to the source. True, power
  still does, but only when
  the sensor connected
  to sockets XS1 and XS2.
   How does this happen? Chip K176LA7
  made like other microcircuits of this
  series (K176), using CMOS technology. Replacement
  The most important property of these microcircuits is that they
  ma low consumption (microamp units)
  per) both in rest mode and in
  switching (operating mode). This property is
  can be used to create hollow
  Residential nutrition feedback
  by including a resistance resistor in this circuit
  resistance up to 300 kOhm.
   But we'll come backto the simulator. It consists of
  two standby multivibrators (single-vibrator)
  tori), each of which is assembled on two
  elements 2I-NOT (DD1.1,DD1.2 and DD1.3,
  DD1.4), transistor power amplifier
  VT1, dynamic head BA1 and sensor,
  connected to the input jacks.
   In general, the sensor represents a
  fight variable resistor, for example, photoresistor
  resistor, thermistor or two conductors
  ka, by water (if the simulator is used-
  used to indicate filling
  baths).
   And now about the operation of the microcircuit in our
  imitator. It is known that to protect it from
  static electricity or from improper
  proper connection to the device circuits
  each of the eight inputs is connected to an internal
  early power buses through diodes.
  If you close the input sockets of the simulator,
  plus the supply voltage goes to
  internal bus of the microcircuit through one of
  diodes, bypassing pin 14. First multivib-
  rator (on elements DD1.1, DD1.2) immediately
  will begin to produce rectangular im-
  pulses following with a frequency of 1...3 Hz, and
  the second (on elements DD1.3, DD1.4) is turned on
  ready for work: it will begin to produce
  nal pulses with a frequency of 200..2000 Hz
  and even when there are 8 elements on the output
  DD1.3 will come from the first multivibrator
  logic level 1.
   From the output of the second multivibrator
  the pulses are fed to the power amplifier, and
  fromsound is heard from the dynamic head.
   If you connect a converter to the input jacks
  exchangeable resistor with resistance up to 100
  kOhm, then the resulting feedback on the power supply
  niya will transform the monotonous intermittent
  sound. Now when you move the slider,
  resistor, i.e. when its resistance changes
  leniya, the sound will resemble the trills of co-
  catch, then the chirping of a sparrow, quack
  ducks, frog croaking, etc.
   The simulator is powered from the source GB1-ba-
  container 3336 or three in series
  single batteries 316, 332,
  343.There is no power switch, because
  In idle mode, the device consumes current
  not less than 1 µA, i.e. much less
  battery self-discharge.

  In addition to the K176LA7 microcircuit, the simulator
  you can use K561LA7 or K564LA7.
  It should be borne in mind that the microcircuits are
  ria K176 of the first releases do not have protection
  diodes and for working in the simulator are not
  are suitable. Make sure the presence or absence
  Wiring diodes is easy using an avometer
  or an ohmmeter, measuring the resistance between
  output 14 of the microcircuit and input pins -
  mi (or even one input pin) it
  elements. As when checking a diode, in one
  The polarity of the avometer probes must be
  there may be a slight reluctance, in another -
  big.
   Instead of the KT3107K transistor, you can use
  thread KT3107L or KT361G (in this case
  resistor R4 should be resistance
  3.3kOhm, otherwise the sound volume will decrease
  ka).Dynamic head - power
  0.1 - 0.5 W with resistor voice coil
  with a resistance of more than 8 ohms. A low-voltage
  compact capsule types DEMSH, DEM-4.Konden-
  Sator S1 - KM-6 or other small-sized
  ny, C2 - any small-sized. Resistors -
  MLT-0.125.
   Some of the simulator parts are mounted on
  printed circuit board (Fig. 2) from one-sided
  of foil fiberglass laminate.
  Board, speaker and source
  power supply is placed in a small housing, on
  the back or side wall of which is
  Repair entrance nests.
   A correctly assembled simulator in setup
  does not need to be changed. To change the tone -
  For better sound quality, you can select a capacitor
  C2 from 300 to 3000 pF, as well as resistors
  R2 and R3 from 50 to 470 kOhm.