The role of cold welding machine energy storage capacitor

How does CD welding work?

With CD welding, the main energy is stored in a capacitor arrangement. In application, that energy is discharged through a transformer creating again low voltage – high current power for welding. CD welding does differ from conventional resistance welding in a number of ways(1).

What is capacitor discharge welding?

Capacitive discharge welding, particularly for large-scale systems, is typically done using film-type capacitors. These capacitors store energy along alternating plates separated by a dielectric film. Charge is stored statically along the lengths of the plates. The basic configuration of the film capacitor is provided in Figure 1.

Can electrolytic capacitors be used in large-scale CD welding applications?

In this study, the suitability of electrolytic capacitor arrangements for use in large-scale CD welding applications was investigated. Baseline for the study was a set-up using a 1280-μF main capacitor. The application was a mild steel weld nut with three projections attached to a similar material substrate.

Do electrolytic capacitors yield identical weld performance results?

The results presented here indicate that electrolytic capacitors, configured to provide similar charge voltage and energy storage, can yield identical weld performance results. Process, mechanical strength, and metallographic results are all identical for the two capacitor arrangements.

Does a film capacitor provide a similar voltage tolerance for CD welding?

Performance was evaluated based on current range behavior and metallographic response. Conclusions from this work include: to film capacitors – An array was developed to provide similar voltage tolerance and system capacitance to a standard film variant conventionally used for CD welding.

What is capacitive discharge or CD welding?

Capacitive discharge or CD welding is a variant of resistance welding(1,2). The process differs from the conventional variants largely in the type of power supply used. Conventional systems provide some variant of alternating current to a transformer arrangement.