How to make a simple 12 volt voltage regulator with your own hands⚡

A 12 volt voltage stabilizer is often used in the electrical circuit of a car. Automotive power supplies (battery and generator) of various 12-volt electrical appliances provide direct current with a voltage of 12.5 to 14 V. Such large fluctuations can lead to damage and failure of sensitive and expensive LED strips, fog lights, radio tape recorders. In addition to the electrical systems of cars, such devices are used in 12-volt power supplies capable of lowering and converting the alternating current of the electrical household network into a direct current that is more suitable for a number of devices.

Varieties of 12 volt stabilizers

Depending on the design and method of maintaining 12-volt voltageI distinguish two types of stabilizers:

• Pulse - stabilizers consisting of an integrator (battery, high-capacity electrolytic capacitor) and a switch (transistor). Maintaining the voltage within a given range of values ​​occurs due to the cyclic process of accumulation and fast charge return by the integrator when the key is open. According to their design features and control method, such stabilizers are divided into key devices with a Schmitt trigger, equalizers with pulse-width and pulse-frequency modulation.
• Linear - voltage stabilizing devices in which zener diodes or special microcircuits connected in series are used as a regulating device.

The most common and popular among car enthusiasts linear devices, characterized by ease of self-assembly, reliability and durability. The impulse type is used much less often due to the high cost of parts and the difficulties of self-production and repair.

Classic model

Classic stabilizers are a large class of devices assembled on the basis of such semiconductor parts as bipolar transistors and zener diodes... Among them, the main function of maintaining the voltage at the level of 12 V is performed by Zener diodes - a kind of diodes, connected in reverse polarity (the plus of the power supply is connected to the cathode of such a semiconductor device, and minus to the anode), operating in the breakdown mode. The essence of the work of these semiconductor parts is as follows:

• When the voltage of the power supply connected to the Zener diode less than 12V he is in in the closed position and does not participate in the adjustment this characteristic of the electric current.
• When exceeding the threshold of 12 volts Zener diode "Opens" and maintains the given value in the range specified by its characteristics.

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If the voltage supplied to the zener diode is exceeded relative to that declared as the maximum by the manufacturer, the device very quickly fails due to the effect of thermal breakdown. In order for any model of a zener diode to serve as long as possible, it is recommended, according to its specification, to clarify the voltage range, current strength in which it should be operated.

Depending on the connection, a distinction is made between two versions of the classic stabilizer: linear - adjusting elements are connected in series with the load; parallel - voltage stabilizing devices are located parallel to the powered devices.

Integral stabilizer

Devices are assembled using small by size microcircuitscapable of working with input voltage up to 26-30 V, giving a constant 12-volt current with a strength of up to 1 Ampere. A feature of these radio components is the presence 3 legs - "in", "out" and "adjustment"... The latter is used to connect regulating resistor, which is used to tune the microcircuit and prevent its overload.

More comfortable and reliable, assembled equalizers based on stabilizing microcircuits gradually displace collected on discrete elements analogs.

Device selection

When choosing a stabilizer, take into account the following characteristics:

• Dimensions. The selected stabilizer should be compactly located in its planned installation location with the possibility of normal access.
• View. Of the commercially available devices, the most reliable, compact and inexpensive are stabilizers based on small microcircuits.
• The possibility of self-repair. Since even the most reliable devices fail, it is necessary to give preference to repairable stabilizers, radio parts for which are commercially available in sufficient quantities and at an affordable price.
• Reliability. The selected stabilizer must provide a constant voltage value without significant deviations from their manufacturer's stated range.
• Cost. For the electrical system of a car, it is enough to purchase a device worth up to 200 rubles.

Also, when choosing a stabilizer, it is necessary to take into account the reviews of their customers, which can be found on specialized forums and sites.

How to make a 12V stabilizer

Simple, but at the same time quite effective, reliable and durable stabilizing devices can be made independently, using simple zener diodes and special small microcircuits such as LM317, LD1084, L7812, KREN (KR142EN8B).

Stabilizer on LM317

The assembly process for such a voltage stabilizing device consists of the following steps:

1. A 130 Ohm resistance is soldered to the middle output pin of the microcircuit.
2. A conductor is soldered to the input right contact, supplying an unregulated voltage from a power source.
3. The left control contact is soldered to the second leg of the resistor installed at the output of the microcircuit.

The soldering process of such a stabilizer takes no more than 10 minutes and taking into account the inexpensive microcircuit does not require large capital investments. With the help of such a device, they power led lights, strips.

Chip LD1084

Assembling a device for stabilizing the voltage of an automobile on-board network using chip LD1084 is done as follows:

1. A conductor with a positive voltage from the diode bridge is soldered to the input contact of the microcircuit.
2. The emitter of a bipolar transistor is soldered to the control contact, the base of which, through two resistors with a nominal value of 1 kOhm, supplies the current of the low and high beam headlights.
3. Two resistors are soldered to the output contact (one is a regular 120 Ohm, and the second is a trimmer, 4.7 kOhm) and an electrolytic capacitor of 10 μF.

To smooth out ripple current after the diode bridge, another one is installed electrolytic capacitor with a capacity of 10 microfarads.

Stabilizer on diodes and board L7812

Simple integral leveler Schottky diode and two capacitors are assembled as follows:

1. Soldered to the input contact of the microcircuit: a diode of the 1N4007 type, the anode of which is connected with a wire to the plus of the power source, the plus plate of a powerful 16-volt electrolytic capacitor with a capacity of 330 μF.
2. The load and the leg of the positive plate of a 16-volt electrolytic capacitor of 100 μF are soldered to the right output contact.
3. A minus coming from the battery and a wire from the minus plates of the capacitors are soldered to the middle control contact.

Such a simple device can power powerful strips of LEDs and a radio tape recorder.

The simplest stabilizer is the KREN board

12 volt voltage regulator circuit based on the roll board (KR142EN8B) includes the following Components:

• Rectifying diode type 1N4007 soldered to the input contact.
• Chip KR142EN8B or KIA7812A.
• Two wires soldered to the output and control pin of the microcircuit and connected to the load and minus of the power supply.

On-board design BANK is an the easiest and fastest to assemble. At the same time, the effectiveness and scope of her is the same as that of other home-made counterparts.