The name of the regulator derives from the regulation as it is understood. Regulators are electrical devices used to balance electrical voltage in areas with fluctuating electrical voltage. It is called REGULATOR that can keep the physical values ​​such as frequency, speed, power, pressure, current and voltage constant at a certain level, and can keep these variables constant by changing them. The city is an electrically operated device that is manufactured with electromechanical or electronic structure that is unaffected by the grid voltage being high, low or variable and which keeps the output voltage constant at the desired level. They allow the electrical energy to go up or down with the hardware components they have, so that the desired steady voltage goes to the receiver.

Fluctuations in the electrical voltage (sudden drop or rise) resulting from the lack or inadequacy of the energy infrastructure in your country or in various parts of the world caused by or caused by the electric distribution companies can cause damage to electrical equipment. The regulator is developed to be used in such places and it is an advanced electronic coil transformer system which is used to increase the low electrical voltage by means of advanced servo motor trafic and to reduce the high incoming electrical voltage to the desired voltage value. In addition, the regulators electromechanically cut the output voltage in the event of a drop in voltage outside the set-up due to the electronic protection system.


How The Regulator Works?

When the load is short-circuited, the regulators cause large currents to flow out. The only shortcoming of simple serial regulators is that they can not respond to these changes immediately. But this is not a problem in complex structures. These regulators, known as shunt-based series regulators, respond instantly to small changes.

In short, regulators compensate for fluctuations in voltage due to changes in the mains voltage or changes in load impedance and make them acceptable.


Why do we need Voltage Regulator?


Today, because all the electrical/electronic devices have sensitive structures, they are affected badly from the voltage change in the mains. In addition to causing the operations which are done in these devices/machines to be left half finished and damaging the quality of the products obtained from these devices/machines, this situation also causes high cost malfunctions in the mentioned devices/machines. Work and production loss causes high costs as well besides the costs for repairment.


Therefore, it has become compulsory to use at least Voltage Regulator or UPS in order to make all the electrical devices operate safely and uninterrupted. Some device/machine manufacturers even exclude the possible malfunctions from warranty coverage when their products are used without Voltage Regulator or UPS.


LEGA Voltage Regulator is a high technology product which you can safely use wherever the usage of Voltage Regulator is compulsory.


Recommended Connection Type





LEGA Servo Regulator has Variable transformer, Servomotor that controls the auxiliary transformer and Electronic Chart that controls this motor according to output voltage.

If the normal mains input voltage drops or rises, the electronic control circuit senses it precisely and the servo motor speeds up. The voltage is applied to the primary winding of the Booster transformer by moving the transformer (Varyak) to the right or left (T1), which is connected to the signal received by this signal (T2). In this way, the voltage fluctuations that can occur in the input are tried to keep the output voltage constant with the tolerance of + 1% at the desired sensitivity at the output and with this added auxiliary equipment, safe operation of the device is ensured.

With a control system that includes a fast response time and a DC motor with high starting torque, it quickly corrects even small changes in voltage.

When the input voltage of the servo motor goes out of the operating limits, the output voltage is automatically set by the limit switches to the desired value and deactivated by the control circuit.


Device Features and Basic Information


Wide power range: Single-phase production from 1 kVA up to 25 kVA,

Three-phase production from 200 kVA up to 3000 KVA


Voltage field:

Standard; 160/250/220 V single-phase

275/450/380 V three-phase


Special regulators: 140/240/220 V single-phase

242/415/380 V three-phase

120/240/220 V single-phase

208/415/380 V three-phase


Regulation speed rate: 90 V/sec.

Output deviation: Unless regulator is used over its own power, no deviations occur on output.

Efficiency: Efficiency is better than 98% since LEGA regulators and transformers consist of high-quality silicon sheet and B-ef class conductive materials. 


Working temperature: Unless regulators are used in acidic and humid environments, working temperature may be up to 50°C.  Additional cooling system is applied for temperatures over such degree. 


Over voltage and phase protection unit (optional): Cut off the output at sudden low and high input voltage(when the regulator is out of setting field). Continuously, monitors the mains voltage and automatically opens the output when it enters the regulator setting field. It prevents low or high voltage in case of any fault that may occur in the regulator. It completely closes the output so that the used devices are not damaged. It prevents the regulator from operating for a long time (cut off the output voltage) in a faulty manner and allows the user to be warned. It will prevent other malfunctions in the regulator. It keeps the regulator constantly checking the output voltages so that it provides to be in compliance with the standards.


By-Pass system: Regulators provide by-pass through high-quality switches. In case of any failure, regulator may be transferred to the mains through switch without any operation on installation with 2x and 6x pole reversion switches. 


Superior Performance:

High quality and long lasting materials. 

Safe and tried system

Silent operation. High efficiency. 

Undistorted output. 

Stable and uninterrupted supply. 

Wide regulation range. High precision. 




Static Voltage Regulator (SVR) connected between mains and load, protect load from irregularities in the mains voltage.

The SVR, operating on the principle of winding change, feeds the load from the windings of its own special transformer. Irregularities that may occur in the mains voltage also change the winding to ensure that the load (motor, rectifier, air conditioner, etc.) operates safely.

In case of overload (130% load and over), consumer devices are fed directly from the network via bypass in case of network tolerance; When the status returns to normal, consumer devices are re-fed via SVR.

The operating system is different from conventional automatic servo voltage regulators. Changes in the number of turns made by the servo motor in the automatic voltage regulators (OVR) are made entirely electronically with the thyristors in SVR. This is the most important reason for the increase in the speed of the answer given to the changes. Instead of a change in a mechanical arrangement, fast triggered fast thyristors ensure the fastest response. In addition, wear and tear on mechanical equipment, need for calibration and maintenance are also avoided.


Why should we use LEGA Static Voltage Regulator..?


LEGA Static Voltage Regulator is completely electronic voltage regulator which does not have any moving part inside of it. It has no eroding, perishing, and maintenance requiring parts. Volt- age regulation is made with microprocessor controlled digital technology in milliseconds. Regula- tion process is made with the help of Thyristor-thyristor module and transformer. It brings the voltage to 220 VAC or three-phase 380 VAC level after one period by measuring the change in the voltage in the first period of the mains. Regulation is made at maximum of 20 milliseconds. This means that regulation speed is 5000 V / sec.

LEGA Static Voltage Regulators are manufactured to operate in the voltage range between 165-250 VAC as standard, and optionally, they are manufactured in wider and narrower ranges.

LEGA Static Voltage Regulators can be manufactured in 1% to 10% output voltage precision. Our standard manufacture is in 3% precision which would be accepted by many electronic de- vices/machines.

LEGA Static Voltage Regulators prevent the load to be damaged by cutting the output voltage with the help of contactor contained in the regulator when the output voltage exceeds 200 – 240 VAC limits. These values can be configured with the help of LCD Panel. 

It is possible to follow up the operation data of the device with the help of LCD screen available on the front panel of the regulator.

LEGA Static Voltage Regulators provide extra protection for sensitive loads thanks to its RFI / EMI filters. It does not produce harmonics because of its operating topology.

LEGA Static Voltage Regulators respond very quickly to the loads that require high starting cur- rent thanks to the semiconductors (Thyristor – Thyristor Module) which are resistant to sudden and high currents and which have been carefully selected during their manufacture. Over-current, over-voltage, low voltage, peak voltage, over temperature and short circuit protections are avail- able and special protections can be added on request.

In the event of possible malfunction in Voltage Regulator, Manual By-Pass switch is included in our product as standard to continue operating via mains.

LEGA Static Voltage Regulators are manufactured from DKP sheet and can be manufactured as special products in different colors with different IP protection classes and electrostatic powder paint which can be designated on request. LEGA Static Voltage Regulators are manufactured sensitively to produce vibration and sound as low as possible.


Areas of Usage:

- Automation Equipment

- Woodworking Machines

- Laboratory Instruments

- Dental Equipment

- Laser equipment

- Phone Shops

- Packing Machines

- Television Transmitters

- Used in CNC Machine Tools

- On Uninterruptible Power Supplies

- In Medical Devices

- In telecommunication

- Jewelry Equipment

- In the Kombiler

- Injection Machines

- Printing machines

- Radio broadcasters

- Textile Machines

- Design Machines

- Technical Equipment

- Motorized Shutters

- Computer Systems

- Fire Safety Systems

- Personnel Attendance Control Systems

- Lighting Units

- Leather Processing Equipments

- Air conditioning

- Market Equipment

- Heating and cooling systems

- Motorized Machines

- Electrical Home Appliances

- Burglar alarm systems


Servo Voltage Regulator

Static Voltage Regulator


Because of the transformer and variac system, the efficiency is around 90%.



Because of the use of semiconductor technology and thyristors in the power units, the efficiency is about 95%.



There are indicator lamps on the front panel for output voltmeter and for input - output.



There are input voltage, output voltage, output% load, temperature, fault information etc. İnfo. with LCD front panel.



It takes up a lot of space for being big.



It's small and ergonomic.


It is not used in extremely humid and dusty environments.



Can be used safely in any environment.



Overcurrent protection is only done by fuse.



It has fuse protection and electronic overcurrent protection.



It is regulated by the variac-engine system. Correction speed max. 90 V / sec.



It is regulated by thyristor technology. Correction speed 5000 V / sec.


The mechanically linked variac-motor system consumes away in time, so the failure rate is higher where the electrical power is too variable.



Because of no moving parts inside, it is not possible to break down with time or operation.


Coals which are moved for regulation on the variac need to be checked and cleaned every 1-2 years.



There are no parts which need maintenance and cleaning.


It is large and heavy.



Small in size and light weight.


It's an old technology.



It's an new technology.


The input voltage range that can be corrected is limited because of mechanical and electrical structure.



The input voltage range that can be corrected is too wide.




LEGA RELAY AUTOMATIC VOLTAGE  Regulators  have all a variable transformer which ensures the voltage stabilization WITH RELAYS and an MCU Card which controls the output voltage.When Input voltage is  235 volts over-temperature protection closes output and the buzzer sound alarm is available.



1.Wide Power Range: 0,5 kVA  - 20 kVA  monophase, monophase production.

2.Voltage field:

Standart; 130/260 V mono phase


Specıal Stabılızer; 80/235 V monophase

3.Regulation speed rate : 120 V/sn.

4.Output deviation : Regulator does not have any deviation when it is not exceeded the original power limts. 

5.Efficiency : LEGA regulators and transformers have more than 98% of efficiency,because they are produced of high quality silica sheets and B class conductor matieral. 

6.Operation Temperature: Regulators can go up to 60°C  when the environment is not too acid or wet. Temperatures which are above that,require additional cooling system.


Additional documents