Those who use an alarm clock powered by a finger-type battery are probably familiar with such a nuisance when the battery suddenly “dead” and the alarm did not go off on time...
It would seem that it could be simpler: just use a battery, but again the problem is that it needs to be recharged sometimes....

This scheme will save you from such trouble: it will provide power to the watch from the network and at the same time recharge the battery in case of a power outage

Capacitors C1 and C2 perform the function of ballast, dampening excess network voltage. With a negative half-wave mains voltage On the upper (according to the diagram) wire, diode VD1 will open and capacitors C1 and C2 will be charged through it. With positive half-waves, the capacitors will begin to recharge, the current will flow, first of all, through the open diode VD2 and the battery G1 and capacitor C3 will begin to recharge. The voltage of a fully charged battery will be at least 1.35 V, and on the HL1 LED - about 2V. Therefore, the LED will begin to open and thereby limit the charging current of the battery. Therefore, the battery will always be in a charged state. Resistor R1 serves to discharge capacitors C1 and C2 when the device is disconnected from the network.

Capacitors C1 and C2 are film capacitors with a rated voltage of at least 300 V, C3 is an electrolyte (preferably tantalum). Diodes VD1 and VD2 - any small-sized rectifier. The HL1 LED must be selected for one whose forward voltage at a current of 10 mA will be 1.9...2.1 V. The battery is nickel-cadmium D-0.1, preferably D-0.125.

CLOCK FROM THE NETWORK

Everyone has a Chinese electromechanical clock in their home, powered by a 1.5-volt AA battery. They consume very little energy and the battery has to be changed quite often, about once every 2-3 months.

Personally, I’m already tired of constantly changing it, so by assembling this circuit and putting a 1.2 V nickel-cadmium battery there, the clock has been working from the mains without replacing the power element for 4 years!

Capacitor C1 for a voltage of at least 400 V, and preferably 600 V for reinsurance, but in no case at 250 V - it will fly out with a 50/50 probability, and it will also burn the clock! Resistor R1 prevents an inrush of current when the rectifier is connected to the network. Its rating is in the range of 100 - 300 Ohms and the power is 0.5 Watt. The diode bridge can be supplied from Soviet KTs407B for a voltage of at least 300 V or assembled from imported IN4007, capacitor C2 for a voltage of at least 16 V. The zener diode here performs a protective function and can be replaced with any one with an operating voltage of 3 - 10 V. The fuse for these hours from the network is drawn just in case and to save space you don’t have to install it. Any battery, even one that barely works, finger-type from 700 mAh. When the lights are turned off, the watch works for almost a week on the battery.

Gift Wall Clock In addition to the stylish design, they carried another small surprise: a galvanic salt cell of AA size was usually enough for no more than 1…2 months of operation. It turned out what is the reason for the rapid discharge of the “battery”.

The stepper electric motor of the clock, instead of one or two activations per second, worked about 10 times, which, on the one hand, ensured smooth movement of the second hand, and on the other, increased the energy consumption of the galvanic cell. To save ourselves from the need for frequent, regular battery replacement, it was decided to make a simple, safe mains power supply, the diagram of which is shown on the website.

The mains voltage is supplied to the bridge rectifier VD1 through current-limiting resistors R1, R2 and quenching capacitors C1, C2. The presence of two resistors R1, R2 of relatively high resistance not only reduces the pulse current through the diodes of the rectifier bridge, but also reduces the likelihood of a strong electric shock if someone decides to replace the battery without disconnecting the watch from the network alternating current. Two capacitors C1, C2, instead of one damping capacitor installed in similar power supplies, increases the reliability of this unit, and with it the safety of operation, which is important for a device operating around the clock.

The rectified voltage is smoothed out by the capacitor SZ and stabilized by the LED HL1. In addition to the Zener diode function, this LED also serves as a backlight, illuminating the watch dial in the dark. The rectified stabilized voltage is supplied through VD1, R4 to the clock mechanism and the galvanic cell, recharging it with a current of about 100 μA. Capacitor C4 ensures the clock runs in the absence of a battery, but operating the clock in this mode, although possible, is undesirable.

In place of HL1, the author used an unknown brand of blue super-bright LED with a diameter of 5 mm and an operating voltage of 3V with a forward current of 20 mA. If you only have ultra-bright 1.5...2V LEDs at your disposal, then you can turn on 2 in series. such LEDs, if necessary, selecting the resistance of resistor R4. If the dial backlight is not needed, then instead of an LED you can connect a zener diode, for example, KS133A, 1N4728A.

The VD1 diode bridge can be replaced by any low-power one, for example, RB154, W04M, KTs407A, KTs422G, or four diodes connected in a bridge circuit, for example, KD521A, 1N4148, 1 N4003. Capacitors C1, C2 are polyethylene terephthalate or polypropylene, for example, the K73-17, K73-24, K73-39 series for an operating voltage of at least 630 V. Oxide capacitors of types K50-35, K50-68 or their imported analogues. Resistors of any type for general use corresponding to schematic diagram power, for example, MLT, OMLT, S1-4.

To simplify installation, all parts can be directly glued to the watch case, for example, with Quintol glue, as shown in Fig. 2. It is advisable to cover the soldering areas and conductive parts of the elements with several layers of tsaponlak, after which it is advisable to cover the area where the elements are placed with a plastic plate of suitable sizes.

If you need the brightness of the “blue” LED to be sufficient not only to illuminate the watch dial, but also to perform the function of a “night light,” then the brightness can be increased by increasing the capacitance of capacitors C1, C2 to 0.22 μF, while simultaneously increasing the resistance of the resistor R4 up to 2…3 kOhm. When setting up and installing the finished device, you should observe safety precautions for working with 220 V AC voltage.

With modern battery prices, it is most profitable to power electromechanical watches of the “Slava” type from the mains. Especially if they are built into furniture, for example, in the kitchen. Previously published circuits of this type are mostly transformerless; such circuits are dangerous, since the mechanism is under mains voltage, so it is better to use a transformer for power supply (see figure). Scheme no originality. It includes a parametric current stabilizer CI, R1, I winding T1 and a 1.5 V voltage stabilizer on VD5, VD6. The author has had such a unit working in tandem with a small AA battery in the kitchen for more than 10 years. Turning relay on a thyristor circuit. It is needed to ensure movement in the event of a loss of mains voltage. The entire block fits completely into the element compartment together with the “finger”. Transformer T1 is a transition from the Speedol radio receiver (VEF). O.G. Rashitov, Kiev....

For the scheme "MELODIC CALL FROM... A WATCH"

Consumer electronics MELODIC CALL FROM... K.KULIKOV'S WRISTS, 443072, Samara-72, 18 km of Moskovskoe highway, 13-61l I had imported electronic wrist watch in a metal case with a faulty indicator. Titles hours there are many of this type (for example, "Montana"), but they are all the same. With the current time on the indicator, the melody is turned on by constantly pressing the “AL.TM” button and briefly pressing the “DATE” button. This principle is implemented in the call. Battery hours replaced with ingredient A343, it lasts for several years. It is best to solder the element, because... salt often appears on the “-” and it oxidizes. Instead of a piezo emitter, a load must be turned on - capacitor C1 type KM (between the housing hours and “spring”). An amplifier is added on a transistor type KT829 (KT827) with a large VST, the load of which is a speaker of 0.5 W, 4 Ohms. A very powerful charger circuit, and for some hours The volume turned out to be insufficient, so I had to buy an additional amplifier on the KT3102D. Block nutrition- a simple 15 V rectifier with a permanent connection of the primary winding to the network. Because Some melodies have a long sound time, which is undesirable for a call; it is supplemented with a time relay that limits the sound time to a few seconds. Scheme borrowed from . Setting up a time relay - there. Literature 1. Radio.-1990.-N 2. p.32.Amateur Radio 7/96...

For the circuit "Electronic watch power supply circuit from the network"

The technical literature describes units for powering electronic-mechanical alarm clocks from the mains. The blocks that replace the 1.5 V galvanic ingredient contain a rectifier with a voltage stabilizer and a step-down transformer. The stabilizer eliminates voltage drops during rare load increases when the signal electroacoustic transducer (bell, electric buzzer) is turned on. An isolation-step-down transformer is required according to electrical safety standards. I believe that for electronic-mechanical ones without a signal electroacoustic converter, an electric bell or a buzzer, the power supply unit can be significantly simplified. Relay connection diagram 527 Due to the negligible current consumption of the clock, it is possible to use a symmetrical transformerless circuit (see figure) with step-down capacitors C1 and C2 of very small capacity (0.033 µF each, 200 V type BGM-2), which make the electrical wires going to the clock safe . What is not in . There may be no stabilization in the unit, since the clock does not have an electric bell or buzzer, and voltage fluctuations in the electrical network are insignificant and do not have a significant effect on the accuracy of the clock. In addition, the periods of decreasing and increasing voltage in the electrical network are approximately equal in length, which causes mutual compensation of slowing down by accelerating it and vice versa. Capacitors C1, SZ and resistor R1 (1 kOhm type BC-0.125 W) can be placed in a special electrical plug plugged into a power outlet, and diodes and capacitor C2 (4...

For the diagram "Indication of connecting electrical appliances to a 220 V network"

For the circuit "Power supply unit for electronic-mechanical watches with digital backlight"

Power supply Network block electronic-mechanical with illuminated dial Source nutrition household wall or tabletop electronic-mechanical alarm clocks with the usual pointer dial usually serve as a galvanic element 343. However, in the house of such hours there may be several, therefore, naturally, the problem of replacing expired batteries periodically arises. In such cases, the galvanic component can be replaced with a mains power supply, which has been discussed many times, for example in. But here another problem arises - stopping the “running” hours when the mains voltage fails. More reliable and convenient to use are network units with power storage devices in the form of small-sized nickel-cadmium batteries D-0.1, D-0.125. Radommicrophone circuits They will ensure normal operation during both short-term and long-term power outages in the network. Proposed block nutrition electronic-mechanical watches, scheme which is shown in Fig. 1, is an improved version of the blocks described in. Its main difference is the likelihood of the dial being illuminated at night. The design of the block corresponds to the dimensions of the 343(R14) galvanic cell, which allows it to be quickly integrated into a watch without any modifications. Capacitors C1 and C2 perform the function of ballast reactive elements...

For the circuit "Home network surge protector"

Due to electrical instability (especially in rural areas) and overvoltage, they can break down. Appliances: electric light bulbs, various heating devices, electric motors of refrigerators and other appliances, radio equipment, etc. I offer an automatic device that controls the condition of the electrical networks and automatically disconnects and switches off the load. The load will be switched on only when the electrical network is in normal condition. Threshold scheme powered by networks through quenching resistors R3, R4 and diodes VD1...VD4. Zener diode VD8 is used to stabilize voltage nutrition scheme. Variable Voltage networks goes through the diode bridge VD1...VD4 to the divider R1, R2. From the resistor R2 slider, which sets the device’s response voltage, the control voltage is supplied through diode VD5 to the base of transistor VT1. Temperature regulator circuit based on a triac Zener diode VD6 is used to protect the transistor from high voltages. At a voltage of networks more than normal, the voltage at the base of the transistor increases, it opens and turns on relay K1. Contacts K1.1 close, relay K2 is activated and switches off the load with contacts K2.1. After the voltage in the electrical relay is restored, K1 is de-energized and turns off relay K2, which turns on the load with contacts K2.1. LEDs VD10, VD12 are used to indicate the status of the device. Relay K2 - any with a winding operating voltage of 220 V, K1 - also any of the RES-9 series. Setting up the device comes down to setting the machine’s response voltage with resistor R2.N. Basenkov, Dobrush...

For the diagram "Power supply for the player"

Nowadays, many people have players from various companies. All of them are powered by finger-type batteries. These batteries have a small capacity and quickly run out when using the player. Therefore, in stationary conditions, it is better to power players via a power supply, since the price of batteries these days is “biting”. In the radio engineering literature there are descriptions of various blocks nutrition for radio devices, including players with 3-volt power supply. The block described below provides output voltage 3 V at a load current of up to 400 mA, which is completely sufficient for nutrition any player or radio. For this block nutrition use a transformer and a housing from the block nutrition microcalculator type MK-62 ("Electronics D2-10m") The primary (network) winding is left at the transformer, and the secondary winding is rewound. Now it contains 270 turns of PEL or PEV 0.23 wire. ...

For the "Telephone call time counter" scheme

Today, in many cities and towns across the country, time-based payment for telephone calls is in effect. Unfortunately, the subscriber learns about the time spent on calls only from the sent invoice. To be able to control accounts. I suggest making a duration counter telephone conversation from the most common switch electromechanical ones powered by one galvanic element of standard size AA (316, “finger”). counter is shown in Fig. 1. The break in the telephone line includes the base-emitter section of transistor VT1, shunted by resistor Rt. The current flowing in the line when the phone is off-hook opens a transistor that completes the circuit nutrition electromechanical watches. They walk, counting down the time to talk. As soon as the telephone is hung up, the closed transistor opens the circuit nutrition hours and stops counting time. The galvanic ingredient G1, which powers the watch, is conventionally shown in the diagram outside its case. K174KN2 microcircuit However, it is by no means necessary to remove it. Enough as shown in Fig. 2, insert more than 190 V between the positive terminal of the element and the contact spring of the network. And by selecting resistor R4, the HL2 lamp is turned on only at a voltage exceeding 240 V. Thus, at a voltage less than 190 V, the lamps are turned off, in the range of 190...240 V One of them shines, and at an even higher voltage, both shine. The device can use neon lamps not only of the type indicated in the diagram, but also any others with an operating current of no more than 1...2 mA.Ya. MANDRIK, Chernivtsi, Ukraine...

For the "TALKING CLOCK" scheme

Consumer electronics TALKING CLOCK V. DENISOV 247400, Gomel region, Svetlogorsk, Parichskaya st. 14-10.I have long dreamed of a “talking” watch, but I could not flash the ROM. Therefore, I used a "TALKING WATCH" wrist watch (made in China). "speaking" is shown in Fig. 1. The time signal sounds independently in each room and in the corridor. For this purpose, dynamic heads BA1...BA4 are used. The amplifier is assembled on four transistors VT1...VT4. Scheme switching (Fig. 2) is assembled on a relay type RES 22. It works scheme So. When you press the SB1 button, relay K 1 is activated and is blocked by its contacts through the normally closed contacts of other relays (K4.2, KZ.2, K2.2). Contacts K 1.1 turn on the loudspeaker BA1 "Hall", and at the same time relay K5 is activated (but is not blocked). Power regulator on ts122-20 Contacts K5.1 turn on the clock speech synthesizer. The time signal sounds in the selected room. The rest of the rooms are silent. As soon as you press the SB2 (SB3, SB4) button, the closed relay K1 turns off, and the other one (K2...K4) turns on. In the bedroom you can put a VAZ in series variable resistor to reduce the volume (not shown in the diagram). Instead of internal batteries, it is better to put two external AA batteries or others with a total voltage of 3 V. The unit is any with output voltages of 5 V and 20 V. The disadvantage of the circuit is that at a certain point in the room you need lay 4 wires (2 p...