Dual Pulse Capacitive Discharge Welders – 125DP, 250DP

Spot welder for batteries and more!

  • Dual Pulse function eliminates surface inconsistencies
  • Microprocessor controlled
  • Optional built-in weld monitor
  • Up to 128 programmable weld schedules


Designed specifically for precision resistance spot welding applications like battery pack welding, the Dual Pulse Spot Welder Series capacitive discharge power supplies (CD welder) are microprocessor controlled, store multiple weld schedules, and provide consistent weld energy to the parts being joined.  AMADA MIYACHI’S dual pulse spot welders deliver high peak energy with fast rise times. This is especially important when welding highly conductive materials such as copper and brass. The control system provides a highly stable output, independent of line voltage fluctuations, resulting in repeatable energy delivery from weld to weld.  The Dual Pulse Series’ short weld times result in minimal part deformation and marking.

The stored energy welding power supply  – commonly called a Capacitive Discharge Welder or CD Welder – extracts energy from the power line over a period of time and stores it in welding capacitors. Thus, the effective weld energy is independent of line voltage fluctuations. This stored energy is rapidly discharged through a pulse transformer producing a flow of electrical current through the welding head and workpieces.

Capacitive discharge power supplies are rated in accordance with the amount of energy they store and the welding speed. The energy stored, expressed in watt-seconds (joules), is the product of one-half the capacitance of the capacitor bank and the square of the applied voltage. The energy delivered to the electrodes is considerably less than this value because of losses in the primary and secondary circuits.

AMADA MIYACHI’S capacitor discharge power supplies provide a ‘Dual Pulse‘ feature which allows the use of two pulses to make a weld. The first pulse is generally used to displace surface oxides and plating, and the second pulse welds the base materials. This feature also reduces spitting.

Advantages of CD welder technology include:

  • Repeatable energy independent of line voltage fluctuations
  • Fast energy release, suitable for welding highly conductive metals such as copper
  • Small heat affected zones

For more information regarding how to choose the right power supply for your application, read our blog: ‘AC, DC, CD or HF: Which Spot Welding Power Supply Should I Use?.

Dual Pulse welders may be used in conjunction with one of our many weld heads as a single operator benchtop unit and is well-suited for integration into semi or fully automated resistance welding systems.  AMADA MIYACHI specializes in designing and building fully integrated, semi-automated and fully automated resistance spot welding machines.  See our Integrated Systems brochure for more information.

And for more information about the resistance welding process read our Fundamentals of Resistance Welding and Fine Spot Resistance Welding Applications.