Abstract: A servomotor control system for multi-axes in which a single servo-amplifier can operate m rotational speed control loops and m current control loops as well for m servomotors simultaneously, where m is a predetermined integer greater than unity, while a single positioning controller with a signal teaching box can handle n servo-amplifiers in parallel, where n is a predetermined integer greater than unity, thereby mn servomotors in total can be controlled by a single system. In the system of the invention, the multiple servomotors can be divided into groups each including up to six servomotors to be controlled as a group and independently from servomotors belonging to other groups. The system of the invention can easily be expanded by a minimum addition of servo-amplifiers and/or positioning controllers to include servomotors more than mn, in which addition of one or more teaching boxes is possible whenever they become necessary.

Abstract: A DC resistance welding apparatus includes a pair of welding electrodes for sandwiching workpieces to be welded therebetween and a circuit connected to the welding electrodes for supplying a welding current to said welding electrodes. The circuit includes a plurality of parallel-connected rectifying circuits each having a welding transformer and rectifying circuit. The circuit allows a large welding current to be supplied to workpieces, and makes the DC resistance welding apparatus small in size and light in weight.

Abstract: A DC resistance welding apparatus includes a pair of welding electrodes for sandwiching workpieces to be welded therebetween and a circuit connected to the welding electrodes for supplying a welding current to said welding electrodes. The circuit includes a plurality of parallel-connected rectifying circuits each having a welding transformer and rectifying circuit. The circuit monitors the power signal produced by inverters in the power supply to determine the proper energization time by producing a pulse signal corresponding to the waveform of the power signal. The rise and fall of the pulse signal is then detected and differentiated. The differential signal is used as a basis to control the energization time of the welding gun.

Abstract: A DC resistance welding apparatus includes a pair of welding electrodes for sandwiching workpieces to be welded therebetween and a circuit connected to the welding electrodes for supplying a welding current to said welding electrodes. The circuit comprises includes a plurality of parallel-connected rectifying circuits each comprising having a welding transformer and rectifying circuit. The circuit allows a large welding current to be supplied to workpieces, and makes the DC resistance welding apparatus small in size and light in weight.