Series switching power supply for station and industrial applications


We at ALEXANDER ELECTRIC often design custom power supplies for the unique needs of our favorite customers. We would like to tell you about one such VIOLET series.

VIOLET series modular power supplies combine the functions of an intelligent device and a powerful power supply. The modules are designed for industrial and stationary applications, including unattended facilities. A complete package includes up to three power modules, a common control unit and a protection and switching unit.

VIOLET power modules with the possibility of parallel operation are designed for long-term powering of equipment with or without a connected battery. The fast analogue control system of the modules provides a high degree of smoothing of the output voltage, allowing the module to work with gel batteries. The smart charger function allows maintaining optimum charge degree of the batteries, accelerated charging of the battery after the mains drop out, significantly prolonging its service life.

Module input voltage ~3x400V. Standard output voltages: 24V, 60V, 110V, 220V, 350V or others as may be ordered; maximum output current up to 200A. The module is a double converter, conversion frequency 20 kHz. The module includes service equipment that monitors the status of each phase of the input network, several temperature sensors, monitors the switching of the fan. In addition, the module has overload and short-circuit protection. When a fault occurs, it is indicated by an LED on the front of the module. The modular layout allows a relatively simple analysis of occurring faults and their elimination. The basic parameters of the modules are given in tables 1 and 2.


Unit nameInput voltage rangeOutput powerOutput voltageNominal output current
VL5000A-400S24-CL~3 x 4004 800 W 24 VDC200 A
VL10000A-400S60-CL11 000 W60 VDC185 A
VL10000A-400S110-CL110 VDC100 A
VL10000A-400S220-CL220 VDC50 A
VL10000A-400S350-CL350 VDC30 A

Table 1 – Units characteristics with one output


Modules can operate independently or be installed in a rack of up to 3 units. Output modules in a rack can be switched to individual load or to parallel operation in any combinations. Individual modules can be switched to stand-alone operation, allowing a faulty power module or control unit to be replaced without interruption to the power supply. In stand-alone operation an additional digital control device can be installed in the module to implement all the “intelligent” functions of the source. When working as part of a rack, these tasks are solved by a separate control unit.


Rack with VIOLET power supply units

Fig. 1 – Rack with VIOLET power supply units


The digital control unit is placed at the top of the rack. It is designed for operational and remote control of the output modules, equipment status control and communication with a remote computer.

The control unit includes:

  • digital control device on the SAB167 processor with original software,
  • Interface (two-row 16-character display and five-button keypad),
  • integrated power supply (-220V or battery in case of mains failure).

In addition, the unit is equipped with operating memory where the information about the rack operation is recorded for remote control and analysis of the modes of its operation for a certain period of time.

When a fault occurs in the control unit, the output modules are switched to the stand-alone operating mode. This mode allows replacing the control unit without interrupting the power supply to the end equipment.

The protection and switching unit is placed in the lower part of the rack. The input and output terminals are accessible after removing the protection panel. Power to the output modules is supplied through a group of fuses. The outputs of the modules are wired to individual circuit breakers and isolation diodes for parallel connection of the modules.


Remote monitoring and control of VIOLET units.

By means of a communication module, VIOLET sources are connected to the service network. This function allows remote monitoring and full rack control.

The main element of the service network is the communication module. It is equipped with a Weintek MT606 industrial computer running the Microsoft Windows CE 4.02 Net operating system. The communication module is connected by fibre optic lines to the control units of the racks (maximum four). The communication module includes a modem, by means of which, in case of emergency situations, the source sends warnings to the service center and receives control commands. The core of the service network is the service centers.

The software modules of the service centers – Servis Center and BS1/CMS – 3 Extended HMI – PC – support the database of objects and sources (including telephone numbers of objects), access passwords for remote control, receive and store warnings of abnormal modes and faults in the database.


Input voltage~ 3 x 400 V
Output voltage

 = 24 V…350 V

Output currentup to 200 A


Ripple level2%
Charging current characteristicIU / IUoU
ProtectionShort circuit, overheating
Operating temperature range0…40 °C
Ambient humidity0…90%
Noise level< 55 dBA
MTBF> 70 000 hours

Unit: 445 x 240 x 600 mm

Rack: 750 x 1800 x 620 mmm


Unit: 40 kg

Rack: 150…300 kg

Table 2 – Tech specs of VIOLET series units


The whole VIOLET system is characterized by high reliability, flexibility, low operating costs. The advantages of the power supplies are their small size and low weight, high operating currents, easy maintenance. The scope of application of Violet power supplies is significantly expanded due to the possibility of their installation on unattended objects.

You can order any custom power supplies through the contact form on the website, by e-mail or by phone.