Abstract: The invention is directed to a control circuit for controlling the current of a welding transformer integrated in an industrial robot. For the purpose of achieving a simpler, more accurate and more reliable detection of contact between the welding tongs (4, 5) and the parts (11, 12) to be joined by welding, there are provided a high-frequency generator (1) for supplying measuring current to the secondary circuit (2) of the welding transformer, an impedance measuring circuit (3), an additional impedance (7) for increasing the impedance of the secondary current (2) to high frequency, an interrupter circuit (8) for interrupting the welding current, and a comparator for enabling the welding current merely in the presence of a differential voltage signal which corresponds to complete contacting of the two parts to be joined by welding.

Abstract: A signal processing device composed of: a signal input for receiving an electrocardiographic signal containing a succession of QRS complexes; a signal output; a digitally operating unit having a transmission factor which is variable in discrete steps and connected between the signal input and output for supplying to the signal output a signal containing representations of the QRS complexes contained in the signal received by the signal input, with the relation between the amplitude of the signal at the signal output and the amplitude of the corresponding portions of the signal received by the signal input being proportional to the existing transmission factor of the digitally operating unit; and a transmission factor control unit connected to monitor the signal at the signal output for increasing the transmission factor of the digitally operating unit by one step in response to each appearance at the signal output of a QRS complex representation having a peak value between selected first and second threshold

Abstract: In a monitoring circuit for monitoring the state of the battery of a card pacemaker, which pacemaker includes an energy storage element normally connected to be charged by the battery and to constitute an energy source for the pacemaker components, the circuit including a voltage detector connected to emit a signal when a parameter representative of the battery state passes a threshold value, the circuit further includes: first switching member for disconnecting the battery from the energy storage element during periodically recurring time periods of given duration; a fixed load having an impedance which is large compared to the internal resistance of the battery and connected to apply to the voltage detector a voltage representative of the current flowing through the fixed load; an element for connecting the load across the battery during each time period for causing the load to be supplied with a current having a value at least indirectly defining the parameter representative of the battery state; and a sto

Abstract: An artificial cardiac pacemaker circuit producing heart stimulation pulses and arranged to operate in any selected one of a plurality of operating modes, the paths traversed by signals in the circuit being different in each operating mode, the circuit including a stage emitting pulses having a predetermined duration and amplitude and/or repetition rate, a stage arranged to actuate further signals during at least a first operating mode in response to such pulses, and a stage operative only during a second operating mode to actuate or suppress such signals at the end, or for the duration, of each pulse in order to at least indirectly fix the time position of each stimulation pulse.