Abstract: Method of metallizing a ceramic substrate so as to obtain on this substrate weldable metallized zones or areas usable at a high temperature, characterized by depositing on a ceramic substrate, an ink including cobalt oxide and forming a hooking layer by forming a compound between the ceramic and cobalt oxide, under an oxidizing atmosphere, and, reducing at about 1,100.degree. C., the oxide superficially so as to obtain a cobalt metal layer and metallized zones or areas weldable by a method known per se.

Abstract: A new triac structure is provided comprising as a classical triac layers N1 to N4 and P1 and P2, and metallizations A1, G and A2 arranged as indicated in the hereinbelow drawings. The layers N1 and N3 have substantially the same boundary in projection and a groove 10 is formed at the boundary of the layer N3 in order to cross the layer P2. Accordingly, the N1 and N3 regions have no common surface in projection. The triac has substantially the same sensitivity in the four triggering modes.

Abstract: The invention relates to a method for diffusing aluminium into a substrate by painting. According to this method, aluminium isopropylate is dissolved in ethoxyethanol at the maximum solubility. This solution is uniformly coated onto a substrate and a diffusion is carried out by placing this coated substrate into an open furnace. This invention is for manufacturing high voltage semiconductor devices.

Abstract: A unidirectional alternating current interrupter operable over full half cycles controls the passage of positive half cycles of a supply voltage V.sub.A into a load 2 disposed in series with a gate junction thyristor 10, a capacitor 13, an N-resistor 12 and a diode 11 are arranged at the terminals of the supply voltage. In this way, during negative half cycles, the capacitor 13 is charged and the gate junction thyristor 10 is rendered conducting from the beginning of the subsequent positive half cycle. To prevent energization of the gate junction thyristor 10 at the end of a negative half cycle, a controlled interrupter is arranged in parallel with the capacitor 13. When this interrupter 15 is closed, the gate junction thyristor 10 cannot be rendered conducting.

Abstract: A synchronous switch for alternating circuits or rectified alternating circuits, the operation of which is automatically synchronized on the passage to zero of the load voltage at its terminals. This synchronous switch contains essentially a semi-conductor element selected from thyristors of a particular type and possibly a diode. The semiconductor element comprises two main electrodes and a control electrode. This element can only be triggered at times when the polarity of the control voltage at the gate is the reverse of that of the first main electrode, and once triggered it then remains closed until the load current crossing it is reduced to zero. The main electrodes may be connected to a rectifier bridge to provide an alternating current switch. The main electrodes may also be connected across a diode, and the devices thus formed can be used to interrupt each phase of a polyphase load current.

Abstract: A power regulating device operating by suppressing full half cycles of power applied to a load from an alternating voltage source. The device includes a controllable semiconductor element of the type which is triggered by removal of current from its control electrode. The anode and the cathode of the controllable semiconductor element are connected across the terminals of a rectified alternating voltage source, and the control electrode receives a fraction of the rectified voltage through an RC circuit and a two terminal threshold device.

Abstract: The present invention relates to photosensitive device comprising a plurality of superposed semiconductive layers, wherein grooves are hollowed on the face exposed to the irradiance in order to reach and to pass through the junctions upon which the operation of the device is dependent and filled with a passivating agent transparent to the incoming light, the improvement being that the sizes of the grooves are selected in order to obtain a maximum efficient volume exposed to the irradiance close to the junctions upon which the operation of the device is dependent and to minimize the the cross-section of the junction.The present invention permits to obtained more efficient photothyristors and phototriacs.

Abstract: A static switch controller synchronized with a passage to zero of the supply voltage, and which is insensitive to spurious firing currents is disclosed. A static switch is controlled by a control circuit having output terminals and input terminals. An alternating rectified voltage is applied across the output terminals and a closing signal is applied across the input terminals. The control circuit comprises a thyristor and a blocking circuit which blocks the cathode of the thyristor when the rectified voltage exceeds a threshold value.

Abstract: This invention relates to a synchronous device for a static relay by a high frequency signal.According to this invention, a high frequency alternating signal source is serially connected with a diode between the anode a and the gate g of a thyristor, the main terminals a and b of which are connected to the terminals of a charge and supply circuit. The thyristor can be triggered only when the voltage between these terminals is lower than a threshold value and control signal is provided for high frequency source. The invention also provides for high frequency synchronous control methods for bidirectional devices.The invention is applicable to a very simple and cheap control system of static relays.