| 摘要 |
Tube elements, i.e. pipes, shaped pieces and armatures of weldable synthetic material, are interconnected by electric welding. The welding operation is made possible by means of a welding sleeve (3) which is connected to the output (4) of the apparatus. A monitoring device (11) allows the engagement of a stage (7) of the welding circuit. The heating power is determined by a quadratic mean of the welding voltage of the network voltage respectively, in a pulse generator (9) which generates a pulse frequency depending upon this value. The generator pulses are added in a counter (10) and when the counted value corresponds to the heating energy, the stage (7) of the circuit is disengaged. If this value is not reached, a monitoring device (5) produces a failure signal. |
