Police quack (siren) on a PIC microcontroller. Police quack (siren) on a PIC microcontroller Circuit of a police quack

DIY police quack on PIC

I offer you a diagram to repeat sound device simulating the signal of a "Police Siren". The device is done on microcontroller PIC16F628. The circuit has two different sirens and a “Quack”.

Basically, a police quack is installed in a car, so look at other diagrams for cars

You will also need a programmer for PIC, here is the diagram

When you press the "Quack" button, a one-time imitation of the "Police Quack" is activated. When you press the "Start" button, "Siren No. 1" turns on, when you press it again, "Siren No. 2" turns on. There is also an effect that simulates the end of the sound of the first siren; to enable this effect, press the "End" button. To stop playback sound effect Click the "Stop" button. This circuit is easy to assemble and does not require configuration.

“PA” – Power amplifier, it is not shown in the diagram. This scheme assembled on a printed circuit board, there is also a simple stabilizer on the printed circuit board to power the microcontroller.

Buttons for of this device were taken from the panel of an old car radio, but simple tact buttons can also be used. The housing for the device is made of plastic, size (55X35X15).

I offer you to repeat the circuit of a sound device that simulates the signal of a “Police Siren”. The device is made on a PIC16F628 microcontroller. The circuit has two different sirens and a “Quack”.

When you press the "Quack" button, a one-time imitation of the "Police Quack" is activated. When you press the "Start" button, "Siren No. 1" turns on, when you press it again, "Siren No. 2" turns on. There is also an effect that simulates the end of the sound of the first siren; to enable this effect, press the "End" button. To stop playing the sound effect, press the "Stop" button. This circuit is easy to assemble and does not require configuration.

“PA” – Power amplifier, it is not shown in the diagram. This circuit is assembled on a printed circuit board; there is also a simple stabilizer on the printed circuit board to power the microcontroller.

The buttons for this device were taken from the panel of an old car radio, but simple tact buttons can also be used. The housing for the device is made of plastic, size (55X35X15).

Download printed circuit boards, project in , firmware you can see below

List of radioelements

Before starting the article, I want to warn you that the use of such signaling devices is illegal, at best you will face a hefty fine. VIP signals have always been considered a luxury item and there are many car enthusiasts who would like to have such a device in their car. This is a device that generates powerful sound signals low frequency.

The signal consists of three main parts.
1) Control panel - in new models, very often the entire generator circuit is located in the control panel. Models such as the right have only one MK, which is programmed and has several operating modes.

2) Power amplifier - Amplifies the signal and supplies it to the emitter
3) Emitter - a loudspeaker that is designed to reproduce a signal.
The generator generates sawtooth pulses and supplies it to the preamplifier, then a signal from preamp goes to the main power amplifier; in our case, this amplifier is made using a cheap TDA2003 monophonic chip.

The circuit has a matching transformer; the signal from the UMZCH goes to the primary winding of this transformer. The secondary windings of the transformer are connected to the bases of powerful key transistors. The signal forces the transistors to open, the latter supply voltage to the primary winding of a more powerful (power) transformer.

At the output of this transformer we already receive an amplified rectangular signal, which is fed to the loudspeaker.

The generator (imitation of a quack) is built on a two-channel pulse generator and counter-dividers. To simulate the sound of a siren, the circuit has a separate microcircuit.

The design diagram is available in the full archive, the download link for which you can find at the end of the article (download is free).

The VIP signal is a special-purpose signaling device that is used by intelligence agencies and is inaccessible to civilians, but this is only at first glance. Recently, the very same cop quack was brought in for repairs.

The signal is quite old, although it was used until recently - of course, by civilians. Modern special signals are made on specialized microcontrollers, this can dramatically reduce the size of the generator board and the circuit itself as a whole, but this signal was used back in the dashing nineties, so to achieve the quack effect, a huge number of components are used here - counters, square-wave generators, low-frequency amplifier , matching transformer, amplifier stage on powerful bipolar switches and power transformer.

The circuit has three main operating modes - loudspeaker, quack signal and howl of police sirens. The effect is obtained using a square pulse generator and a counter, then the signal is pre-amplified and fed to the input of a low-frequency amplifier.

Today we will look at the latest module for a VIP signal (quack) - this is a power amplifier. Recently they brought me a quack with a failed UMZCH. If you own such a device, then you don’t need to turn it on for more than 10 seconds - the amplifier will burn out! Well, if you have a quack like the cops, then you can safely turn it on as much as you want! In police quacks, the signal is amplified using an audio converter with powerful transistors that can work for hours without burning out. Chinese cheap signals use an amplifier based on TDA2003 microcircuits; thanks to the bridge connection of two microcircuits, it was possible to obtain a power of up to 30 watts. The power is, of course, insignificant compared to police 300-watt flashlights, but the sound is quite loud. You can also find it on our website. So, after turning it on, it became clear that the world circuits had burned out; they are very easy to get or buy on the radio market for an insignificant amount. Microcircuits can also be replaced with TDA2002, although the latter are rarely found, domestic analogue TDA2003 microcircuits - the famous 174un14.

The microcircuits were replaced, and the reason why they burned out was also found out - if you turn on the device for a few seconds, the microcircuits will boil, the fact is that they are placed on a common heat sink with a small area.

The heatsink was also replaced with a larger one. A typical bridge circuit for connecting amplifiers on the TDA2003 chip is shown below.

2 ohm resistors can be replaced with homemade ones. To do this, take the paste from a helium pen and wind 20 turns of wire with a diameter of 0.5 millimeters on it, turn to turn. You can wind it in two rows to make the resistor compact. All polar capacitors used in the circuit are selected with a voltage of 16 or 25 volts.

The power for the amplifier is supplied through a relay, but it can be excluded from the circuit, since here you can use a direct connection with wires, the currents are not so large that the wires cannot withstand.

The capacitance of the input capacitor can be deflected in one direction or another; this will not affect the operation of the amplifier and sound parameters in any way, since the amplifier works as a signal repeater. The load of the head, which is connected to an 8 ohm amplifier. It is known that the microcircuit can operate at a load of 2 ohms, with a bridge connection of 4 ohms; to increase the volume, you can use a small transformer (iron) with two windings. The primary must be connected to the amplifier output. The primary winding should have a resistance of 3.2-4 ohms, wound with a wire of 0.7-1 mm. We wind the secondary winding with the same wire and it should have the same resistance as the first. This way you can increase the power by 1.5-2 times. Author - Arthur Kasyan (AKA).