Compact Frequency Inverters




Delivers stronger bimetal welds and longer electrode life with less part deformation.

Frequency Inverter Features

  • Reliable nugget formation and improved weld quality with no splash closed loop feedback control.
  • Built in monitoring capability
  • High Speed, suitable for automated systems (more than 5 welds per second).
  • 4 channel transformer selector keeps costs down (IP-215A, IP-217A)


How Frequency Inverter Power Supplies Work

Three Phase, fully rectified DC current is repeatedly switched on and OFF by the semiconductor switches S1 S2, producing AC current (greater than 1 kHz). This current flows the welding transformer Tw, and the current I is rectified on the transformer secondary side and flows to the head H. The weld current is easily controlled and response is rapid because both the efficiency and power factors are excellent. Furthermore, because of the transformer’s small size, these power supplies are prefect for inclusion in automated systems.


Quality Assurance with Secondary Constant Current Control

Variations in resistance during welding are detected and fed back to the control unit. A frequency inverter circuit is used to maintain fixed power during welding (Power = Voltage x Current). The advantage of this type of control is that reliable welds can be achieved regardless of fluctuations in power source voltage or non-uniform workpiece resistance. Even with shunting or worn electrodes, quality welds with no splash and constant strength can be obtained even at lower pressures.


Lower Costs with Sequential Welding

MA-600A weld transformer selector — (for use only with the IP-215A and IP-217A).

  • Simultaneous squeeze and sequential welding
  • One frequency inverter power supply can be used with up to 4 weld transformers.
  • Weld schedules can be set individually for each weld
  • Random initiation is possible with the optional MIS-0104 PLC

Select the Power Supply and Transformer Suited for your Welding Needs

Power Supply — Transformer Pairings

Transformers (below)Frequency Inverter Power SuppliesSuggested Applications
IT-500AXXXXelectron guns, miniature relays
IT-501XXXXlamps (tungsten filament), battery tabs
IT-510AXXXXprecious metal accessories, tape heads
IT-511AXXXXbimetal contacts (nickel, brass, copper, etc.)
IT-512AXXXX*coil fusing, TV tube masks
IT-530AXX*electrolytic capacitor terminals, eyeglass frames

* Seam Welding available with options

For more general information about the transformers and power supplies, in addition ot the tables below, there is another table comparing all the power supplies and transformers available.

Power Supply Specifications

Power Source:220 VAC +/-10% 3-Phase 50/60 Hz
Control Frequency:2 kHz1 kHz
Maximum Output Current:50 A200A
Control Method:Constant Current,
Constant Power,
Constant Voltage
Constant Current,
Constant Power
Weld Schedules:7 Schedules15 Schedules
Timer Settings:Squeeze Delay0-->9999 ms / 0-->999 
Rise 1, 20-->49 ms0-->400 ms / 0-->20
Weld 1, 20-->99 ms0-->600 ms / 0-->36
Cool0-->99 ms0-->999 ms / 0-->99
Fall0-->49 ms / 0-->9
Hold, Off0-->999 ms / 0-->999
Heat Settings:Heat 10.20--2.00 KA 0.40--4.00 KA 
0.20--2.00 V 0.40--4.00 V 0.40--5.00 KA 
Heat 20.04--4.00 KW0.16--9.99 KW0.20--5.00 KW
Current Monitor:0--9.99 KA+/-0-->99%
Voltage Monitor:0--99.9 V(Display Only)
Power Monitor:0--9.99 KW+/-0-->99%
Weight:22 lbs. (10 kg)28.6 lbs (13  kg)28.6 lbs (13 kg)
External Dimensions (W x H x D): 5.6 x 10.6 x 17.2 inches 
(142 x 269 x 436 mm)
6.8 x 10.6 x 18.3 inches 
(172 x 269 x 466 mm)
6.8 x 10.6 x 18.3 inches 
(172 x 269 x 466 mm)

Transformer Specifications

5 kVA4.5 kVA9 kVA7.9 kVA15.0 kVA17.2 kVA
Input Voltage:
2 kHz1 kHz
Secondary Voltage 
without load:
6.25 V8.1 V6.5 V8.57 V12/10 V9.37 V
Maximum Current:*2000 A1500 A4000 A3000 A4000 A5000 A**
Duty Rate:8%7%6%5%5%7%
Cooling:-- Air Cooled --Water Cooled
1.5 gal./min
(6 L/min)
Weight:14.3 lbs. 
(6.5 kg)
15.4 lbs. 
(7 kg)
28.6 lbs. 
(13 kg)
30.9 lbs.
(14 kg)
41.9 lbs. 
(19 kg)
33.1 lbs. 
(15 kg)
External Dimensions
(W x H x D): 
5.4 x 6.9 x 11 in. 
(138 x 176 x 280 mm)
5.4 x 6.9 x 11.6 in 
(138 x 176 x 295 mm)
7.2 x 7.2 x 13.4 in 
(183 x 184 x 340 mm)
7.2 x 7.2 x 14.2 in 
(183 x 184 x 360 mm)
7.2 x 7.2 x 16.1 in 
(183 x 184 x 410 mm)
6.1 x 4.1 x 11.8 in 
(155 x 105 x 300 mm)

* The Maximum current depends on the Rectifying diode specifications
** With a 15 cycle weld time

For more information, or help selecting or pricing a Microwelder system, feel free to contact T. J. Snow.