PCSS - The Phase Controller with a Soft Start, Digital Synchronization, and Overcurrent Protection for Resistance Welding Machines

The controller is one of the most challenging parts of today's welding machines. It provides a major contribution to the quality and repeatability of the weld. A well designed controller must possess specific functions that provide smooth and reliable operation.

Certainly the most crucial function of the controller is the ability to switch current with a full range of load parameters such as resistance, inductance, and power factor which is closely related to the former two parameters. The next important functions are phase resolution (time accuracy), ability to operate within given environmental specifications, internal temperature rise, and maximum overload capability. The controller must be a low cost and a highly reliable device with a small size and weight. Although this list is not comprehensive enough, it still shows the principal specifications that can severely affect the controller's performance and aptitude. It is a very challenging task for a designer to compromise all of these requirements into one design. This is why it is often a hard task for a welding machine designer to find a suitable controller on the market. At DIGIWELD we kept this in mind when we designed our PCSS.

Utilizing the most advanced modern design technology such as auto compensation and mixed signal design allowed DIGIWELD to develop a low cost, small, yet powerful controller. With a volume of about 10 cubic inches PCSS can control a single phase welding machines up to 30 kVA! The line voltage range is up to 240 V AC and current range is up to 125 A. Moreover, depending on application it is possible to extend the current range up to 200 - 250 A. The phase resolution is 1% for the middle of the regulation curve. Progressive modern electronic technologies like solid state devices and surface mount components allowed DIGIWELD to create a controller with an extremely low internal power dissipation, high reliability, and maintenance free operation.

Measuring 2.28 x 2.28 x 1.95 inches (58 x 58 x 50 mm) without knobs and the start button, the PCSS phase controller weighs only 8 ounces (225 grams) which makes it especially suitable for portable and hand-held welding machines.

PCSS has linear measurements of approximately 3 - 4 times less than the closest competitor's device (2" instead of 7 - 8"). Based on the preliminary estimate we can expect that the DIGIWELD controller will cost the same 3-4 times less. Definitely the PCSS is the smallest and cheapest digital controller on the today's market.

Read an article. Click here.


Copyright © 1999 EUROSCIENCE