40VA–2500VA
Rated Capacity
Range

CNC & Automation
Machine Tool &
Control Panels

100% Isolation
Stable Control &
Auxiliary Power

OEM & ODM
Custom Voltage &
Mounting Design

 

 

JBK SERIES

JBK Series Machine Tool Control Transformer

Reliable Control Power for Machine Tools, CNC Equipment and Industrial Automation

The JBK Series Machine Tool Control Transformer is designed to provide reliable control power for machine tools, CNC machines, industrial automation equipment, electrical control panels and general machinery. It is commonly used to supply control circuits, local lighting, indicator lamps, relays, contactors and other auxiliary electrical loads.

VoltNex Power manufactures and supplies JBK Series industrial control transformers with customized primary and secondary voltages, rated capacity, frequency, terminal configuration and mounting dimensions. Standard and custom solutions are available for OEM machine builders, automation integrators, electrical panel manufacturers, distributors and industrial equipment suppliers.

Built with high-grade silicon steel laminations and premium copper windings, our JBK transformers ensure low core loss, high operating efficiency, superior overload resistance, and long service life under continuous heavy-duty industrial operating conditions.

Key Features

Wide Power Range
40VA – 2500VA
Custom Voltage Options
Primary & secondary voltage customized
Single & Three Phase
50Hz / 60Hz frequency
Multiple Applications
Machine tools, CNC, automation, panels
High Insulation Class
Class B / F / H (optional)
Flexible Mounting
Foot/bracket mounting, custom terminals

Technical Specifications

Product Type Machine Tool Control Transformer
Series JBK1 / JBK2 / JBK3 / JBK4 / JBK5
Rated Capacity 40VA – 2500VA
Frequency 50Hz / 60Hz
Input Voltage Custom (100V – 690V)
Output Voltage Custom (100V – 690V)
Phase Single Phase / Three Phase
Winding Material Copper / Aluminum (optional)
Efficiency ≥ 95%
Insulation Class Class B / F / H (optional)
Application Machine tools, CNC, automation
Control Power Control circuits / Auxiliary power
Lighting Supply Available
Signal Supply Available
Mounting Foot / Bracket mounting
Terminals Custom configuration
Design Open-type / Enclosed (optional)
Service OEM / ODM / Custom Manufacturing

Applications of JBK Machine Tool Control Transformers

CNC Machines
01

CNC Machines

Control power for CNC machining centers, CNC lathes and precision machine tools.

Machine Tools
03

Machine Tools

For conventional and automated machine tools requiring reliable control voltage.

Industrial Automation
02

Industrial Automation

Control power for automated production equipment, PLC systems and industrial machinery.

Control Panels
04

Control Panels

Integrated into electrical control cabinets and machine control panels.

Motor Control
05

Motor Control

Used in contactor, relay, starter and auxiliary motor control circuits.

Lighting & Signal Circuits
06

Lighting & Signal Circuits

For machine lighting, indicator lamps and auxiliary signal circuits.

 

 

JBK Series Specification & Dimensions

The JBK series section provides exact dimensional parameters and schematic drawings to streamline cabinet space planning and mounting for OEMs and panel builders. In addition to standard catalog models, VoltNex Power offers full engineering customization—including tailored power capacities, primary and secondary voltage configurations, custom frame sizes and mounting dimensions, special terminal types, and enhanced insulation classes to meet your precise application requirements.

Model Bmax (mm) Dmax (mm) Emax (mm) Mounting Pitch Installation Hole (K or KxJ) Fmax (mm)
A C
JBK3-40, 63 78 75 89 56±0.4 4.8×9 51±2 12
JBK3-100 85 90 91 64±0.4 4.8×9 68±2 12
JBK3-160 96 97 105 84±0.4 5.8×11 73±2 14
JBK3-250 96 105 105 84±0.4 5.8×11 85±2 14
JBK3-400 120 105 123 103±0.4 7×12 82±2 18
JBK3-630 150 105 145 128±0.5 7×12 86±2 22
JBK3-1000 160 195 145 140±2 7×12 158±2 18
JBK3-1600 180 225 155 155±2 7×12 180±2 18
JBK3-2500 200 250 171 165±2 7×12 210±2 18
JBK Series Machine Tool Control Transformer Outline Drawing and Installation Dimension Diagram for JBK1–JBK5

JBK Series Models & Capacity Specifications

Detailed rated power capacity range across the JBK control transformer series. Full customization available for tailored VA ratings, special voltage configurations, and structural dimensions.

Model Series Rated Capacity (VA)
JBK1 40 – 2500
JBK2 40 – 2500
JBK3 63 – 2500
JBK4 63 – 2500
JBK5 100 – 2500

VoltNex Power JBK Series Control Transformers

OEM & Custom Engineering Capabilities

We supply standard catalog models as well as bespoke transformer designs engineered specifically for your enclosure layouts and technical parameters.


  • Custom VA & Voltages: Primary/secondary multi-taps for global machinery

  • Physical Dimensions: Tailored stack heights, core sizes & mounting hole pitches

  • Industrial Protection: High-temperature insulation (Class B/F/H) & VPI treatment

  • Compliance Standards: Built to meet international CE, IEC, and RoHS requirements

 

 

Custom JBK Series machine tool control transformer for CNC machines, industrial automation and control systems

Custom JBK Machine Tool Control Transformer

Need a Different Voltage, VA Rating or Mounting Size?

VoltNex Power provides customized JBK Series machine tool control transformers according to your equipment requirements. We can customize primary voltage, secondary voltage, rated capacity, frequency, winding material, insulation class, terminal configuration, mounting dimensions and enclosure design for OEM machine builders and industrial automation projects.

Custom Voltage

Custom VA

Custom Dimensions

Custom Terminals

Custom Winding

OEM / ODM

Bulk Production

 

 

JBK Series Manufacturer & Factory

VoltNex Power is a premier China manufacturer and direct factory specializing in industrial control transformers, machine tool control transformers, and customized industrial power equipment. With advanced VPI insulation processes and rigorous automated testing, we deliver highly reliable single-phase control transformers tailored to global industrial standards.

We provide high-volume OEM/ODM manufacturing for CNC machine builders, industrial automation integrators, switchgear assembly plants, and electrical panel manufacturers worldwide, ensuring long-term operational stability and maximum cost efficiency.

Factory Direct
Competitive Price

Quality Assurance
ISO / CE / RoHS

Global Supply
Fast Delivery

Global Wholesale & Export Supply

We provide B2B wholesale export solutions for JBK Series machine tool control transformers across North America, Europe, Asia-Pacific, Latin America, and the Middle East. Our specialized logistics network guarantees fast dispatch, safe packaging, and complete compliance documentation for seamless international customs clearance.

Whether you require standard catalog models, multi-tap primary/secondary voltage configurations, or custom mounting specifications, we partner with overseas distributors, wholesalers, and equipment manufacturers to deliver factory-direct value.

USA Canada UK Germany
France Italy Spain Poland
Australia Brazil UAE and more…

FREQUENTLY ASKED QUESTIONS

A JBK Series machine tool control transformer is a dry-type control transformer designed to provide suitable control and auxiliary power for machine tools, CNC machines, industrial automation equipment, electrical control panels and other industrial systems. It converts the available input voltage to the required control voltage while providing electrical isolation between the primary and secondary circuits when an isolated winding configuration is specified.

JBK control transformers are commonly used to supply power to contactors, relays, solenoid valves, electromagnetic components, PLC-related circuits, indicators, control devices and other auxiliary loads. The transformer can be configured according to the machine’s voltage, VA capacity, frequency, installation space and wiring requirements.

Voltnex Power supplies customized JBK Series machine tool control transformers for OEM equipment manufacturers, automation integrators, control-panel builders and industrial distributors.

JBK control transformers are primarily used for industrial control and auxiliary power applications where a stable and suitable control voltage is required.

Typical applications include:

  • CNC machine tools
  • Conventional machine tools
  • Industrial automation equipment
  • Electrical control cabinets
  • Machine control panels
  • Factory production machinery
  • Motor control systems
  • Relay and contactor circuits
  • Solenoid and electromagnetic devices
  • PLC control systems
  • Industrial lighting and auxiliary circuits
  • Packaging machinery
  • Textile machinery
  • Metalworking equipment
  • Automated production lines

The transformer can step down or otherwise convert the available supply voltage to a lower control voltage suitable for the machine’s control circuit.

The main difference is the intended application and electrical design.

A standard power transformer is generally designed to transfer larger amounts of electrical power for distribution or equipment power supply. A JBK control transformer is optimized for control circuits and auxiliary loads, where voltage stability, electrical isolation, compact installation and the ability to handle control-circuit inrush loads are important.

JBK control transformers are typically installed inside or alongside machine control cabinets, CNC equipment, electrical panels and industrial automation systems. Their VA ratings are generally selected according to the control load rather than the main motor power of the machine.

For example, a large CNC machine may use a relatively small control transformer to supply its contactors, relays, solenoids, control electronics and other auxiliary circuits.

JBK Series machine tool control transformers can be manufactured with different primary and secondary voltages according to the application.

Common industrial primary voltages include:

220V, 380V, 400V, 415V, 440V, 480V and 660V

Common control voltages may include:

12V, 24V, 36V, 110V, 115V, 120V, 220V and other customized voltages.

The actual voltage combination should be selected according to the machine’s electrical schematic and control-circuit requirements. Voltnex Power can customize the primary voltage, secondary voltage, frequency, VA rating, terminal configuration and mounting dimensions for different industrial equipment.

For international OEM projects, the transformer can also be configured according to the electrical requirements of the destination market.

The correct VA rating should be selected based on the total continuous control load plus the inrush VA requirements of components such as contactors, relays, solenoids and electromagnetic devices.

A basic selection process is:

Transformer VA Rating ≥ Continuous VA Load + Allowance for Inrush VA

Simply adding the wattage of every control component may not provide an accurate transformer size because some inductive control devices can draw considerably higher current during energization.

For a machine tool control transformer, it is important to consider:

  • Continuous control load
  • Contactor pickup VA
  • Solenoid inrush current
  • Relay coil requirements
  • Motor starter requirements
  • Simultaneous energization
  • Control voltage
  • Duty cycle
  • Future load expansion

Voltnex Power can help select the appropriate JBK transformer capacity based on the customer’s electrical schematic, load list or equipment specifications.

Yes. Custom JBK control transformers for CNC machines are one of the important applications of this product family.

For OEM CNC equipment, the transformer can be customized according to the available installation space and electrical design. Customization may include:

  • Primary voltage
  • Secondary voltage
  • VA capacity
  • 50Hz or 60Hz frequency
  • Copper or other specified winding materials
  • Insulation class
  • Terminal configuration
  • Terminal quantity
  • Mounting holes
  • Mounting dimensions
  • Transformer height and width
  • Lead-wire configuration
  • Enclosure requirements
  • Nameplate information

This makes the JBK Series suitable for CNC machine builders that require a control transformer to fit a specific control cabinet or machine electrical system.

A properly designed isolating control transformer provides galvanic isolation between the primary and secondary windings.

This means there is no direct conductive connection between the primary and secondary circuits when they are electrically separated windings. Isolation can help separate the control circuit from the incoming power circuit and is commonly used for machine control and auxiliary power applications.

The actual insulation system and dielectric performance depend on the transformer design and specified requirements. For applications where electrical isolation is critical, the required insulation level, dielectric withstand voltage and applicable standard should be confirmed before production.

For industrial automation and machine-tool applications, an isolated control transformer can be an important part of the overall electrical protection and control architecture.

Yes. JBK Series control transformers are suitable for many industrial automation and electrical control applications.

They can provide control power for:

  • PLC control systems
  • Contactors
  • Relays
  • Solenoid valves
  • Electromagnetic brakes
  • Control switches
  • Sensors and auxiliary devices
  • Machine interface circuits
  • Industrial indicators
  • Automation control panels

The transformer is typically integrated into a control cabinet or machine electrical system. The required output voltage and VA capacity should be selected based on the actual automation circuit.

For automated production lines, the control transformer can be designed together with the control cabinet’s voltage, terminal arrangement and available mounting space.

JBK, BK and JMB are commonly used Chinese industrial control-transformer designations, but their exact specifications and naming conventions can vary by manufacturer and market.

In a typical product classification:

  • BK Series – general low-voltage control transformers for industrial machinery and electrical control circuits.
  • JBK Series – machine tool control transformers commonly associated with machine tools, CNC equipment and control cabinets.
  • JMB Series – commonly used for lighting and control applications, including auxiliary lighting circuits.

For international customers, it is more useful to specify the actual input voltage, output voltage, VA rating, frequency, insulation requirements and application rather than relying only on the model designation.

Voltnex Power can manufacture the appropriate control transformer according to the customer’s electrical requirements and application.

Yes. JBK control transformers are commonly used to supply control power to contactors, relays, solenoid valves and other electromagnetic control components.

However, the transformer must be correctly sized for both the normal operating load and the temporary inrush current generated when inductive devices are energized.

For example, if several contactors or solenoids can be energized simultaneously, their pickup VA should be included when selecting the transformer capacity. A transformer that is sized only according to the steady-state VA may experience excessive voltage drop during simultaneous starting.

Providing the contactor model, coil voltage, quantity and simultaneous operating conditions allows the transformer VA rating to be selected more accurately.

JBK Series control transformers can be designed for 50Hz or 60Hz industrial power systems.

The frequency should be specified when ordering because transformer magnetic design, losses and operating characteristics are related to the operating frequency.

For export applications, customers should provide the electrical system requirements of the destination country or machine. Voltnex Power can configure JBK control transformers for different international voltage and frequency requirements.

For example, a transformer for a 60Hz North American industrial machine may require a different specification from a transformer intended for a 50Hz European or Asian machine.

Yes. Voltnex Power provides OEM and ODM manufacturing of JBK Series machine tool control transformers for industrial equipment manufacturers, automation companies, electrical panel builders and distributors.

Custom engineering can cover:

  • Voltage conversion
  • VA rating
  • Winding configuration
  • Copper winding
  • Frequency
  • Insulation class
  • Terminal arrangement
  • Lead-wire length
  • Mounting dimensions
  • Mounting holes
  • Nameplate
  • Protective enclosure
  • Mechanical structure
  • Packaging requirements

For OEM projects, customers can provide an existing transformer sample, electrical drawing, technical specification, nameplate information or installation dimensions. The transformer can then be developed according to the required electrical and mechanical parameters.

The applicable standard depends on the destination market, transformer design and customer’s technical requirements.

For machine-tool and industrial control transformer applications, standards such as IEC 61558-2-2 may be relevant to the safety requirements for control transformers, while other IEC, UL or customer-specific requirements may apply depending on the project.

For export orders, the required certification and compliance should be confirmed before production. Voltnex Power can discuss applicable standards, insulation requirements, dielectric withstand testing, temperature-rise requirements and other technical specifications with customers.

If a customer requires a transformer for a specific market such as the USA, Canada, Europe, Australia or other regions, the required compliance requirements should be specified during the quotation stage.

Each JBK control transformer should undergo appropriate quality-control and electrical testing according to its design and applicable requirements before shipment.

Typical transformer inspection and testing may include:

  • Winding resistance testing
  • Insulation resistance testing
  • Dielectric withstand testing
  • Voltage ratio verification
  • No-load current testing
  • Output-voltage verification
  • Terminal and wiring inspection
  • Visual and dimensional inspection
  • Nameplate verification
  • Mechanical mounting inspection

For OEM and bulk orders, additional inspection and testing requirements can be discussed according to the customer’s quality specification.

The goal is to ensure that the finished machine tool control transformer meets the specified electrical, mechanical and application requirements before delivery.

Voltnex Power supplies custom JBK Series machine tool control transformers directly from the manufacturer and factory for industrial customers, OEM equipment manufacturers, control-panel builders, automation companies, distributors and wholesale buyers.

Customers can request customized specifications for CNC machines, machine tools, industrial automation systems, control cabinets and auxiliary power applications.

For a quotation, provide as much of the following information as possible:

  • Primary voltage
  • Secondary voltage
  • VA rating or estimated load
  • 50Hz or 60Hz
  • Single-phase or required configuration
  • Insulation requirements
  • Terminal configuration
  • Mounting dimensions
  • Quantity
  • Application
  • Destination country
  • OEM or standard requirement

Based on these details, the manufacturer can recommend a suitable JBK control transformer configuration and provide a quotation for custom, OEM, ODM, wholesale and bulk orders.