What is TLA

Theunissen Lastechniek is a leading Dutch manufacturer of high quality welding equipment. TLA was founded in 1982. With about 10 employees a large scale of products are manufactured, such as:

  • Stick welding powersources according to all safety regulations with remote control without additional control cable
  • MIG/MAG welding equipment fitting extremely well to shipyards, general construction, sheet metal production and automotive repair
  • TIG welding equipment such as:
    .Monofase portable inverters, AC and DC current
    .3-Fase powersources for watercooled TIG AC and DC welding with all features

Products are mostly delivered via stock-holding distributors. A great part of our production is sold under private labels.


The last 10 years there has been a complete revolution in the world of MIG/MAG welding machines. The primary chopped TIG and Elektrode machines (inverters) were in use for many years and so the MIG equipment should also be an inverter. The reliable cupper winded transformer did not fit in the vieuw most constructors of welding machines had. The machines had to have a small size and low weight. After a few working years there seems to be some disadvantages on this technic. The used electronics were not suitable for the heavy industrie and shipbuilding and the machines were not easy to repair. High reparation costs had to be made to keep the machines working.

In 1999 TLA introduced the first generation Chopper MIG’s, a secundairy chopped weldingmachine with a conventional heavy cupperwinded transformer, choke and a conventional rectifier. At this moment we have the third generation and the welding performances are great.

What is a Chopper MIG ?

The Chopper power source contains the following parts:

  • cupper winded main transformer
  • cupper winded choke
  • rectifier(diode bridge)
  • Mosfet Chopper with capacitors

How does it work?

The primairy voltage (3 x 400 Volt)is being transformed to 3 x 35 Volt AC before it rectified to 60 Volt DC. This DC voltage will be stabilised through the capacitors and send to the Mosfetchopper. The chopper will set the output voltage to pulses. The width of the pulses will make the value of the welding voltage. The regulation of the voltage comes from an advanced and reliable digital regulation system.
The big advantage of this system is that all the active components are on the low voltage side what makes the machine more reliable.


Theunissen Lastechniek B.V.
Nobelweg 5
6669 MV Dodewaard
The Netherlands
tel: 0031488412328
fax: 0031488412723
email: info@theunissenlastechniek.com

Contact Form