A simple two-tone call with your own hands. Essay: Electronic circuits for home and everyday life. Electronic doorbell with triple tone alarm

Below are schematic diagrams and articles on the topic of “call” on the radio electronics site and radio hobby site.

What is a “bell” and where is it used, schematic diagrams of homemade devices that relate to the term “bell”.

This device will be useful for those who have several rooms in their apartment, but only one telephone set (TA) and its call may not be heard from the next room or kitchen. The simplest way out of the situation may be to connect another bell in parallel to the TL in another room... The device, the diagram of which is shown below, allows you to get quite pleasant, non-repetitive trills. This is achieved through the use of a pseudo-random sequence generator (PSG), assembled on logic chips DD1...DD3. Its construction is well known... A simple melodic bell for an apartment, the diagram of which is shown in Fig. 16.3.0, contains a minimum number of parts and can be assembled by any radio amateur with a little knowledge of a soldering iron. The sound (frequency of generated oscillations) of the bell is selected by rotating the axis... You can breathe new life into an ordinary rotary telephone if you replace the electromagnetic bell with an electronic one, assembled according to the diagram below. After such a replacement, the sound of the phone will become more pleasant and melodic. The bell circuit is assembled on one K176LA7 microcircuit and two... A melodious bell is installed instead of a regular residential electric bell. The bell sounds with trills, which can be changed by simply altering it. The melodic bell uses two logic chips and three transistors. The oscillation frequency of the generator... The two-tone bell circuit on microcircuits is assembled on two microcircuits and one transistor. Logic elements D1.1—D1.3, resistor R1 and capacitor C1 form a switching generator. When the power is turned on, capacitor C1 begins to charge through resistor R1. As the capacitor charges... An electric apartment bell can sound like a canary if you install a simple device according to the following diagram. The bell consists of a canary oscillator (transistors V1, V2) and a time delay machine (transistors V3 and V4). The latter is necessary so that time... The described circuit serves to create a simple melody with a pleasant sound. Can be used as a doorbell, sound alarm, electronic clock alarm. The entire device is built using a single integrated circuit. Element A of the 4093 chip with elements R1, P1, C4... The presented music box can replace a traditional doorbell. Built on the UM3482A integrated circuit. Plays 12 popular melodies. The integrated circuit is built using CMOS technology. In its structure, it has a permanent ROM memory in which melodies are recorded. ... The offered doorbell is characterized by a very pleasant sound. The specialized integrated circuit from HOLTEK HT2828D used in its design has a complex internal structure, due to which the number of external elements required for this device is reduced to a minimum. The elements of the kit allow you to assemble a sound signaling device that simulates the sound of a three-tone gong. A special feature of the circuit is the presence of three buttons. Pressing each of them plays a different sound. Rice. 1. Internal structure of the NT2823 circuit. Rice. 2. Schematic diagram. ... When power is applied to the circuit, a sound signal is heard, very similar to a bird alarm. Power is supplied through the bell button. Power source - 9V battery. The DC operating mode of the transistor is set by resistor R1. Generation depends on C1 and C2, as well as inductance... To signal that someone has arrived, you can hang a bell above the door, at such a height that the opening door will hit it. Of course, you can very carefully open the door and hold the bell with your hand... But that’s not the point, I just wanted to make an electronic equivalent of this... This device is designed for wired remote calls to up to seven subscribers. It can be used as an apartment bell in a communal apartment, as a bell to call employees from different offices or departments, and for other purposes, for example, for seven-command remote control... Schematic diagram of a doorbell with harmonious sound, made on the MC14093CP chip. Residential calls, now, are usually electric or electronic. Electric ones produce the sound of either a ringing rattle or a bell. And electronic ones reproduce fragments of musical... Schematic diagram of a homemade electronic bell on the CD4060 chip, we assemble a useful device with our own hands. There are many schemes for electronic doorbells. Usually they are made on specialized microcircuits - music or sound synthesizers, or... If you want to replace a regular mechanical bicycle bell with an electronic one, you can make such a simple device, the circuit of which is described here. The main advantage of this device is the scanty current consumption with sufficient sound volume. This was achieved by the fact that in quality... Schemes of devices built using an apartment radio call are interesting homemade products for the home. Nowadays you can buy an apartment radio bell in every electrical goods store. This is a device consisting of two blocks - a transmitter and a receiver. The radio button transmitter represents...

Diagram of a call with the sound of Big Ben

This sound effect can be created in circuitry using two timer chips.

The first oscillator is tuned to a frequency of 1 Hz, and the second is modulated by a changing signal from the output of the first. The frequency of each generator can be changed by resistances R1 and R2. Resistor R1 can be used to regulate the speed of switching from one tone to another, and resistor R2 can regulate the tone of the sound signal. The speaker is designed for an impedance of eight ohms.

Nowadays there are a wide variety of low-power communication devices on sale that are available without registration, such as VHF pocket radios, radio-controlled toys, and recently radio alarms have also appeared. In general, the amateur radio design is very interesting in terms of its breadth of application. It consists of two blocks - a remote control button and the signaling device itself.

A relay is connected to the anode of the thyratron, for example RES6), the rear contacts of which are connected in parallel to the contacts supplying a regular doorbell. To protect against false alarms of the sensor and ignition of the thyratron, a parametric stabilizer is used, built on a zener diode VD1 and ballast resistance R3.

The sensor is made of aluminum rivet, the resistance R1 and the thyratron are located in a small housing. To indicate the activation of the sensor, a hole is made in the housing opposite the thyratron. When you touch the “rivet” the thyratron will flash brightly. Adjusting the circuit of the sensor device consists of setting the variable resistance R5 to a voltage of 170 V on the oxide capacitor at a minimum mains voltage; such voltage can be applied using an autotransformer. The design is borrowed from No. 6 1990.

The design consists of a control generator, on elements D1.1-D1.3 digital IC K155LAZ, generating control pulses, the frequency of which is determined by the nominal value of capacitance C1 and resistance R1

At given ratings, the generator switching frequency is 0.7...0.8 Hz. Pulses from it are sent to tone generators and, in turn, connect them to a ULF assembled on a transistor. The first generator is built on elements D1.4, D2.2, D2.3 and generates pulses with a repetition rate of 600 Hz, the second generator consists of D2.1, D2.4, D2.3 and operates with a frequency of 1000 Hz, which is regulated by selecting the SZ , R3. The sound volume is adjusted by R5.

The design is easy to assemble and adjust. The basis is three master sawtooth voltage generators, each of them operating at its own frequency.

F=1/(2C1R2ln(1+2R3/R1))

where C1 is in farads, R1, R2, R3 is in ohms. The signals from the output of all three generators are mixed and sent to an amplifier, which is loaded into an eight-ohm load.

The first design replaces the door bell, and is triggered when the door is opened, reacting to even a slight change in its position, while the other eliminates the question of connecting it

Limiting the time the doorbell sounds

As you know, they are turned on by a button at the door and work as long as the button is pressed. If the button is accidentally shorted, which happens when it is made from low-quality plastic, or it is specially shorted, for example, with a match, then the bell will work continuously. The call is not designed for this mode of operation. At best, it will burn, and at worst, a fire is possible.

When the caller holds the button down for a long time, the long ringing gets on the nerves, so it is advisable to limit the sound time to 5-7 seconds. The time limit design described below allows this to be done.

This is how the circuit works. When you press the SB1 button (at the door), voltage is supplied through the normally closed contacts K1.1 to the bell. It starts to sound. At the same time, voltage is supplied to the chain R1, VD1, K1, C1. Initially, C1 represents a short circuit for current limited by resistor R1. Capacitor C1 begins to charge through R1, VD1. After a few seconds, C1 will charge to the operating voltage of relay K1. The relay is activated, contacts K1.1 are opened and the bell is disconnected from the network. When the SB1 button is released, capacitor C1 is discharged through the relay coil K1. When the voltage on C1 becomes less than the release voltage of relay K1, it will return to its original state, contacts K1.1 will close and you can call again. By selecting R1 and C1 you can adjust the sound time of the signal.

Scheme of one bell for two doors

If an apartment or house has two entrances, it is not always clear where the call is coming from. This design will save us from this drawback. When button S2 is pressed, the relay is self-locking. At the same time, the second indicator lamp lights up. The bell will ring until the capacitance C1 is charged to the supply voltage level. If the signal needs to be reapplied, S2 is released and C1 is discharged through the winding. Lamp H2 continues to light until S3 is open.

If guests press the S1 button, the bell sounds in parallel with the H1 indicator lamp turning on. The duration of the sound is one second, the pause is 2 seconds.

The two-tone bell circuit on microcircuits is assembled on two microcircuits and one transistor.

Device diagram

Logic elements D1.1—D1.3, resistor R1 and capacitor C1 form a switching generator. When the power is turned on, capacitor C1 begins to charge through resistor R1.

As the capacitor charges, the voltage on its plate connected to pins 1 and 2 of logic element DL2 increases. When it reaches 1.2... 1.5 V, a logical “1” signal (“4 V”) will appear at output 6 of element D1.3, and a logical “0” signal (“0” will appear at output 11 of element D1.1). ,4 V).

After this, capacitor C1 begins to discharge through resistor R1 and element DLL. As a result, rectangular voltage pulses will be formed at output 6 of element D1.3. The same pulses, but shifted in phase by 180°, will be at pin 11 of element D1.1, which acts as an inverter.

The duration of charge and discharge of capacitor C1, and therefore the frequency of the switching generator, depends on the capacitance of capacitor C1 and the resistance of resistor R1. With the ratings of these elements indicated in the diagram, the frequency of the switching generator is 0.7...0.8 Hz.

Rice. 1. Schematic diagram of a two-tone call on two K155LA3 microcircuits.

The switching generator pulses are fed to the tone generators. One of them is made on elements D1.4, D2.2, D2.3, the other - on elements D2.4, D2.3. The frequency of the first generator is 600 Hz (it can be changed by selecting elements C2, R2), the frequency of the second is 1000 Hz (this frequency can be changed by selecting elements SZ, R3).

When the switching generator is running, at the output of the tone generators (pin 6 of element D2.3), either the signal of one generator or the signal of another will periodically appear. These signals are then sent to a power amplifier (transistor VI) and converted by head B1 into sound. Resistor R4 is necessary to limit the base current of the transistor.

Setup and details

Using trimming resistor R5 you can select the desired sound volume.

Fixed resistors - MLT-0.125, trimmer - SPZ-1B, capacitors S1-SZ - K50-6. The K155LAZ logic chips can be replaced with KIZZLAZ, K158LAZ, the KT603V transistor can be replaced with KT608 with any letter index. The power source is four D-0.1 batteries connected in series, a 3336L battery or a stabilized 5 V rectifier.

Two tone call

The two-tone call contains a control generator assembled on elements D1.1-D1.3 of the K155LAZ microcircuit and generating control pulses, the frequency of which depends on the capacitance of capacitor C1 and the resistance of resistor R1.

With the ratings indicated in the diagram, the generator switching frequency is 0.7...0.8 Hz. The control generator pulses are fed to the tone generators and alternately connect them to an audio amplifier assembled on a transistor, VI. The first generator is made on microcircuit elements D1.4, D2.2, D2.3 and produces pulses with a frequency of 600 Hz (regulated by selecting elements C2, R2), the second generator is made on elements D2.1, D2.4, D2.3 and works with a frequency of 1000 Hz (regulated by the selection of elements SZ, R3). The sound volume is controlled by resistor R5.

Details. Resistors type MLT-0.125, trimming resistor type SPZ-16; capacitors S1-SZ type K50-6; microcircuit K155LAZ, K133LAZ, K131LAZ, K158LAZ; transistors KT603V, KT608, KT503 with any letter index.

Two-tone call on microcircuits

A two-tone call on microcircuits is assembled on two microcircuits and one transistor.

Logic elements D1.1-D1.3, resistor R1 and capacitor C1 form a switching generator.

When the power is turned on, capacitor C1 begins to charge through resistor R1. As the capacitor charges, the voltage on its plate connected to pins 1 and 2 of logic element D1.2 increases. When it reaches 1.2...1.5 V, a logical “1” signal (4 V) will appear at output 6 of element D1.3, and a logical “0” signal (0.4 V) will appear at output 11 of element D1.1. IN). After this, capacitor C1 begins to discharge through resistor R1 and element D1.1. As a result, rectangular voltage pulses will be formed at output 6 of element D1.3. The same pulses, but shifted in phase by 180°, will be at pin 11 of element D1.1, which acts as an inverter.

The duration of charge and discharge of capacitor C1, and therefore the frequency of the switching generator, depends on the capacitance of capacitor C1 and the resistance of resistor R1. With the ratings of these elements indicated in the diagram, the frequency of the switching generator is 0.7...0.8 Hz.

The switching generator pulses are fed to the tone generators. One of them is made on elements D1.4, D2.2, D2 3, the other - on elements D2.1, D2.4, D2.3. The frequency of the first generator is 600 Hz (it can be changed by selecting elements C2, R2), the frequency of the second is 1000 Hz (this frequency can be changed by selecting elements SZ, R3). When the switching generator is running, at the output of the tone generators (pin 6 of element D2.3), either the signal of one generator or the signal of another will periodically appear. These signals are then sent to a power amplifier (transistor V1) and converted by head B1 into sound. Resistor R4 is necessary to limit the base current of the transistor. By adjusting resistor R5 you can select the desired sound volume.

Fixed resistors - MLT-0.125, trimmer - SPZ-1B, capacitors S1-SZ - K50-6. Logic chips K155LAZ can be replaced with K133LAZ, K158LAZ, transistor KT603V - with KT608 with any letter index. The power source is four D-0.1 batteries connected in series, a 3336L battery or a stabilized 5 V rectifier.

Electronic call

When power is applied to the circuit, a sound signal is heard, very similar to a bird's trill. Power is supplied through the bell button. Power source - 9V battery. The DC operating mode of the transistor is set by resistor R1. Generation depends on C1 and C2, as well as the inductance of the primary winding of the transformer. The transformer was taken as a ready-made output from an old transistor receiver “Yunost”. In principle, a transformer from any transistor receiver with a push-pull transformer ULF is suitable. Any speaker.

Krivlov P. Journal Radioconstructor No. 12-2015

Musical call

This device is the simplest and most economical of all those published in the literature. Basically, such a bell is intended for use as an apartment bell, although it can also find other applications, for example in toys or as an alarm clock bell.

The circuit is based on the BT66T-2L music synthesizer microcircuit (Fig. 1). Inside it has an RC oscillator and a melody generator, which consists of 127 notes and repeats periodically. Elements C1, R2, VT1, VT2 set the sound operating time, and VT3 is the power amplifier. The last transistor is installed only if you need to increase the volume of the sound emitter (BA1 can be connected directly to the output of the synthesizer, as shown by the dotted line).

Rice. 1. Electrical circuit of a musical bell

After pressing the SB1 button, the time the signal sounds depends on the capacitance C1 and the resistance R2 (with the values ​​​​indicated in the diagram, it is approximately 2...3 s). If desired, you can increase the playing time by increasing C1.

Power is supplied from two 1.5 V galvanic elements. In standby mode, power consumption is almost zero, since all transistors are in the off state (will be equal to the leakage current of capacitor C2), so a switch is not required.

Rice. 2. PCB topology and arrangement of elements

To install the elements, you can use the printed circuit board shown in Fig. 2. Any details will do.

Malyshev S.Yu. Mariupol

Touch room bell

The diagram of the touch-sensitive apartment bell is shown in Fig. 1.

The B1 bell will turn on when you touch the E1 sensor contact, which can be any conductive object electrically isolated from the ground.

When you touch the sensor contact E1, the voltage induced at the base of the transistor VT1 opens it, causing the opening of transistors VT2 and VT3. In this case, bell B1 beeps.

The touch-sensitive apartment bell circuit uses high-voltage transistors, and resistor R1 must have a power of at least 1 W.

Attention! When setting up the device, you must remember that its elements are under dangerous mains voltage!

From the site http://radiolub.ru

Scheme of a touch doorbell on a microcircuit

Transformer T1 is the output transformer from a small transistor radio. Dynamic head BA1 with a power of 0.05-0.5 W with a voice coil with a resistance of 4-50 Ohms.

Power source - Krona, Corundum battery or two 3336 batteries connected in series. The sensor element can be made of foil PCB. The distance between the contact pads should be 1.5...2 mm, and the gap between them should be protected from dirt and moisture with varnish or paint. The shape of the contacts of the sensor element can be any.

Setting up a call comes down to selecting capacitor C1 to obtain the required tone of the sound signal for a specific design of the sensor element.

Rice. 1. Scheme of a touch-sensitive doorbell (a) and its circuit board (b)

I.A. Nechaev. Mass Radio Library, Issue No. 1172, 1992.

Simple doorbell

There are situations when there is a need for a simple doorbell that has sufficient volume and contains a minimum of details. Doorbell circuit shown in the figure, consists of a transformerless power supply with a damping capacitor C1 and a simple audio frequency generator assembled on transistors VT1 and VT2. Resistor R2 serves to limit the peak current through the bridge diodes VD1...VD4. To start a call, press the SB1 button. A device correctly assembled from serviceable parts does not require adjustment. Capacitor C1 is used type MBGCH, K42-19, K73-17, K78-4. Instead of transistors VT1 and VT2 indicated in the diagram, you can use transistors of the type MP40, MP41, MP42 And MP36, MP38 respectively. The dynamic head BA1 should have a power of 1-3 W, like 1GD36, 1GD40, 2GDSh9, ZGDSH1. From the site http://radiopill.net

Homemade call based on a subscriber loudspeaker

The proposed device is made on the basis of a conventional broadcast loudspeaker, contains a minimum of parts and is capable of delivering a fairly strong sound signal, since the emitter is a speaker. This bell is powered from an autonomous low-voltage source (battery). The device does not consume energy in standby mode and is absolutely safe.

Fig.1. Schematic diagram of a homemade call based on a subscriber loudspeaker.

Due to the small number of parts, there is no point in making a printed circuit board. Installation is carried out using a hinged method. The terminals of the speaker, transformer, and 68-kilo-ohm potentiometer are used as supports for soldering.

The volume control of the base loudspeaker - R1 on the electrical circuit diagram performs the function of adjusting the pitch of the generated signal, which is set at will. The switch (toggle switch, button or other contact connector) is placed in a convenient place at the entrance to the entrance, section on the floor or the entrance door of the apartment.

Any of the low-power germanium MP39 - MP42 can be used as transistor VT1. The choice of resistor R2 is equally uncritical; the most common VS, MLT, ULM with a rated power of 0.125 W or more are suitable. Capacitor - any type. Elements R1, T1 and BA1 are from the broadcast loudspeaker.

It happens that a correctly assembled bell does not work when the power is connected. Then you should swap the ends of one of the windings of transformer T1. However, the lack of generation at the audio frequency may also be a consequence of substandard transistor VT1. In this case, you will have to replace it with another one that has a higher gain.

If the pitch adjustment range of potentiometer R1 is not satisfactory, then it can be easily changed by selecting the capacitance of capacitor C1. But the sound of this call also depends on the supply voltage. By changing the pitch of the bell, you can also judge the degree of discharge of the power source and promptly change a worn-out galvanic cell or battery. Just remember to maintain polarity, because the transistor does not tolerate polarity reversals.

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