Abstract: A surveillance device, e.g. a fire alarm or an intrusion detector, includes a mount having a connector block, and an insert having a sensor assembly, a printed circuit board with evaluation electronics, and an electrical contact to the connector block. The printed circuit board is a plug-in card with a contact strip. For insertion, with the mount disposed at a horizontal surface, for example, the insert is first moved vertically and then displaced horizontally. In the horizontal displacement, an electrical connection is established between the contact strip and the connector block.

Abstract: A discoil cold cartridge filled with a latent heat storage medium of which a discoid main wall (1) serves to act together with a scraper and stirrer of an ice-cream maker, is formed by at least two parts joined together, of which one part consists of the discoid main wall (1) facing the scraper and stirrer tool and the other part of a trough-shaped base (2). The discoid main wall (1) serves to act together with the scraper and stirrer tool and is designed as an inherently stable die-cast part least one wall of the base (2) is itself reversibly adaptable to the change in volume of the latent heat storage medium in phase transition.

Abstract: An ionization chamber with two electrodes having a variable spacing and with a radioactive source for the ionization of the electrode gap therebetween includes an adjusting mechanism for the positional adjustment of one of the electrodes relative to the other. The mechanism is such that a spring element presses the adjustable electrode against at least one point of the adjusting mechanism.Several arrangements are disclosed for adjustably mounting a cup-shaped electrode in the housing of the chamber in such a manner that it is readily adjustable and will not undergo spurious readjustment as a result of vibration of shock.

Abstract: A method of grinding a toothed cutter for hair-cutting apparatus, the cutter having at least one strip-shaped row of cutting teeth, comprises pressing the entire row into engagement with the circumferential surface of a rotating grinding shaft while longitudinally orienting such row of cutting teeth parallel to the axis of the grinding shaft.

Abstract: To render an ionization-type sensing element essentially immune to changes in ambient conditions, principally temperature or operating voltage, while still using low-current draining circuits to sense response of the ionization chamber of the sensor, the threshold response level of a field effect transistor (FET) is arranged to have approximately the same temperature response characteristic, within the range of ambient temperature considered, as the ionization cell so that the overall circuit or system combination of the cell and FET amplifier will have a response which is essentially independent of ambient temperature or similar conditions. The source path of the FET is connected to a voltage divider which is so dimensioned that the voltage division ratio (R.sub.2 /R.sub.1) is related to the temperature coefficient (.alpha.) of the base-emitter voltage of the FET and the temperature coefficient (.beta.) of the measuring ionization cell chamber:R.sub.2 /R.sub.1 = (.beta./.alpha.) - 1.

Abstract: To render an ionization-type sensing element essentially immune to changes in ambient conditions, principally temperature or operating voltage, while still using low-current draining circuits to sense response of the ionization chamber of the sensor, the threshold response level of a field effect transistor (FET) is arranged to have approximately the same temperature response characteristic, within the range of ambient temperature considered, as the ionization cell so that the overall circuit or system combination of the cell and FET amplifier will have a response which is essentially independent of ambient temperature or similar conditions. The source path of the FET is connected to a voltage divider which is so dimensioned that the voltage division ratio (R.sub.2 /R.sub.1) is related to the temperature coefficient (.alpha.) of the base-emitter voltage of the FET and the temperature coefficient (.beta.) of the measuring ionization cell chamber:R.sub.2 /R.sub.1 =(.beta./.alpha.)-1.