Bright Stars Electronics

Karve Road, Pune, Maharashtra

Impulse Welding is an ultra modern way of metal joining, which replaces many other techniques such as riveting, soldering or conventional a welding.

The actual welding takes only a few Milliseconds (Tentatively 5 to 8 mSec) so only the very welding zone is heated up while neighboring zones remain practically cold. There is no distortion, tarnishing, discoloring or annealing of metal around the welding zone. Welding time is so short that sufficient melting heat is produced in the welding zone before heat dissipation starts, unavoidable with longer welding times. This also means that the total amount of heat applied is small as possible as hardly higher than necessary for the weld itself. The welded parts stay practically at room temperature.

The high currents from Impulse Welders make this method applicable even for metals of high electrical and thermal conductivity such as copper, silver, gold and even platinum.

With Impulse Welding machines, electrode cooling is not required even at very high production rates. Electronically stabilized charging with proper feedback keeps the voltage across the capacitor absolutely constant and gives constant welding energy even at power line variations giving highly reproducible welding results.

In the Impulse Welding the required welding energy is stored in a CAPACITOR BANK, being charged during the intervals between welds. As the charging of the capacitors takes place at quite slow rate, there is a great saving on power supply requirements as compared to conventional ac welding machines. There is no sudden heavy burden on the mains supply creating problems to other machines and environment.

Production speeds are limited only by the time required for job feeding mechanism, which is sufficient time for recharging the required capacitor banks, because of negligible short welding times.

Welding performance is dependent on Welding Energy and Applied Pressure. With Capacitor Discharge welding machine, the Energy is maintained constant and the pneumatic Weld Head maintains the required pressure. A special pneumatic Weld Head is provided for welding very fine wires. This special unit applies very low pressure for fine wire welding, which is adjusted for different type of jobs, depending upon the size, type conductivity and type of the material to be welded.

A Simple Manual Weld Held can also be provided for non critical applications.
Potential Free contact is provided for inert gas purging (both post & past time) operation.

Separate Manual operation is possible for trials and testing.

ADVANTAGES :

Hot Junction Welding Machine is most suitable to weld the Hot Junction of a SIMPLEX / DUPLEX / TRIPLEX ungrounded and grounded Mineral Insulated (MI) thermocouples of various types, and sizes ranging from 1 mm to 6 mm. Oxidization is totally avoided as the welding process takes just few milliseconds, and with inert Gas Atmosphere. The use of ARGON inert gas for pre weld and post weld times does not allow the junction to oxidize at all. The welding is done stored energy, rater than the current, forming a weld as a beautiful bright bulb, and is immune to power supply variations and changes.

A Capacitor bank is charged to the required voltage, monitored digitally, depending on the Energy requirements, according to the size and type of thermocouple. Two more additional capacitor banks can be added for thick wires. Actuation of the START switch purges Argon for predefined time, (pre-welding), the ARC strikes, discharging Heavy current through the joint fusing the same, forming a bulb, thus completing the welding. The Argon continues to flow for predefined time (post weld time) cooling the thermocouple, avoiding oxidization. Same method is adopted for Duplex / Triplex Thermocouples, with fine adjustment of torch.
The thermocouple is prepared and adjusted properly, in a special fixture. Welding torch and can be moved in both X and Y direction with very fine Lead screw type of precise arrangement, for accurate positioning, for welding Simplex, Duplex, Triplex thermocouples. The UP / DOWN movement with locking facility allows the torch movement vertically. All these functions make the welding of DUPLEX / TRIPLEX Thermocouples without removal of the same. A Clip, is used to connect the other end of the thermocouple, forms the second electrode. A gap of about 0.5-to1.0 mm is adjusted between the junction and torch to avoid any contamination of the welding electrode, during welding. Welding can not take place, with indication, if the torch touches the junction.
The provision is made to adopt Microscope for inspection. The unit works on 230 / 110 V AC mains.

The actual welding takes only a few Milliseconds (Tentatively 5 to 8 mSec) so only the very welding zone is heated up while neighboring zones remain practically cold. There is no distortion, tarnishing, discoloring or annealing of metal around the welding zone. Welding time is so short that sufficient melting heat is produced in the welding zone before heat dissipation starts, unavoidable with longer welding times. This also means that the total amount of heat applied is small as possible as hardly higher than necessary for the weld itself. The welded parts stay practically at room temperature.