Contact us now: sales@woodruffeng.com

Building custom magnetic field coils, pulsed power systems, and scientific instrumentation since 2005


We can design, build, and wind custom coil assemblies for your application in the lab or in the factory. If you have a design in mind or need assistance shaping your magnetic field, let our engineers know:

Email us or call (505) 407-3259


NEW: Try the Woodruff Engineering Inc. Coil Generator for an instant design.

Magnets & Coils

We have designed for a wide range of operating conditions and specifications. From low energy systems (1W) to systems requiring cooling towers (225kW), from systems requiring to cancel out the earth’s magnetic fields (less than 1 Gauss) to high field applications (up to 3T). We have engineered for continuous operations and pulsed (s pulses). We have designed power supplies for all systems, or paired best options available. We have designed for coils to be operated in a wide variety of conditions - from in air, in water, and in vacuum. We encase magnets in protective shrouds where needed, and have encased in epoxy. We build many magnets per month currently. All coils are custom - we use contemporary CAD and FEM tools to design from the ground up. Custom Magnetic Coils:

  • Helmholtz coils,
  • Maxwell coils,
  • Solenoids,
  • Saddle Coils;
  • Water-cooled coils for continuous operation at low voltages;
  • Coils for operation in Ultra High Vacuum environments;
  • Low inductance coils for use in High Voltage pulsed power systems;
  • Microscope coils;
  • Full design of magnetic field and coil assembly;
  • Heavy-Build Polyimide insulated magnet wire for high temperature applications;
  • Reverse engineering of old coil systems;
  • Power supplies and diagnostics

Two-axis Helmholtz coils

Helmholtz field calculation using COMSOL, CAD model render (Fusion360) and as-built coil. Coil was 18cm ID, taking a maximum current of 6A in 14AWG wire to produce 30mT (300 Gauss) magnetic field. Total weight of the coil is 7.4 Kg.

Single axis Helmoltz coil water cooled

Two axis Helholz coils.

Single axis Helmholtz coils designed to reach 1 kGauss, with a welded water-cooling shroud.

3 axis axis Helmholtz coils designed for instrumentation calibration at 100 Gauss.

Modified Helmholtz coils for use in a calibration jig.

Maxwell coils give a larger volume of uniformity than Helmholtz coils.

Mirror coil set with 7T magnets at each end, 1T magnets in the middle.

Water-cooled 3 axis coils designed to fit around a cryostat.

2kW air-cooled coils, designed for use in a system that could not use water.

14 coil array for use in an industrial process. Each coil is 36 ¼ in x 2 ½ in x 24 in or The coils will weigh about 60 kg.

This electromagnet was designed for use in a bio lab for subjecting samples to a magnetic field using a pulsed power supply (shown below). Cooling was achieved with water-cooling on the OD.

3D field configurations for microscope stages and sensor calibration.

Water-cooled high field magnets, with 1m ID, 225kW of heat to be extracted.

1T water-cooled copper magnet with iron to give peak field for 30s.

Precision magnet.

8ft-on-a-side 3 axis Helmholtz coil set to provide ~1Gauss field at the center to zero-out the earth’s magnetic field.

10cm ID 0.25T continuous operation with water-cooling HH coil set with separately cooled winding packs in each coil.

30cm ID 30mT water-cooled copper magnets.

Read Testimonials from our Customers

Helmholtz Coil Calculator

Try our Helmholtz Coil Calculator to find the maximum field strength of a coil set. What is a Helmholtz Coil?







What are Electromagnetic Coils Used for?

Electromagnetic coils produce a magnetic field when a current runs through them. This is due to Ampere's Law. The strength of the field varies with the amount of electric current. These fields have many applications both for scientific research and for industrial uses.

Here are some common uses of electromagnets:

  • Motors for electric cars
  • Generators
  • Transformers
  • Magnetization or demagnetization of ferrous objects
  • Magnetic levitation
  • Magnetic field gradients for research
  • High field strength electromagnets for research
  • Particle Accelerators
  • Plasma Physics Research