A method for implementation of the integrated protection of bipolar transistors from the current overload in the control circuit based on a combination of the element with N-shaped volt-current characteristic (IVC) with a bipolar transistor has been considered. The features of the appliances implemented using this method are the presence of a static transfer N-shaped CVC, as well as one or more chains of positive feedback, which permits to restrain the operating input current and output voltage within the specified limits. Using this method will permit to create a semiconductor structure of bipolar transistors with the built-in protection against the current overload in the control circuit.
- Counter: 1339 | Comments : 0
A multifunction threshold positional-sensitive photoswitch with an S-shaped current-voltage characteristic has been suggested. It has been shown that the breakover voltage of such element depends on the spatial position of the light beam on its surface. The results of the mathematical modeling and experimental research of this instrument have been presented.
- Counter: 1154 | Comments : 0
In development of radio isotope electric feed sources of long-term service for various application in the space branch, medicine, nano-and microsystem equipment, cryptography and telecommunications one of the most important issue is the determination of their reliable operation temperature range. In the work the influence of the negative and positive temperatures in the range from -60 to +60 °C to the output parameters of radio isotope sources of electrical feed, based on the energy double conversion has been investigated. It has been shown that in the indicated temperature ranges the voltage of the radio isotope idle running is 4 times increased. In this case the maximum value of the returned power loading is realized at temperature near 0 °C.The influence of temperature on all stages of the energy conversion has been analyzed. The investigations demonstrate that a significant reduction of the idle running and the shape of the returned power curve are determined by two mechanisms: a decrease in the luminous intensity of radioluminescent light sources (temperature quenching of lumninescence emission) and a decrease in the efficiency of the photoconverters. In this case, the decrease in the efficiency of photoconverters is weakly expressed in the negative temperature range (from -60 to 0 °C), and the main contribution, to the change of the output parametrers of the power sources is made by the thermal quenching of luminescence in the light source. In the positive temperature range both processes have a significant effect on the reduction of the output voltage and power.
- Counter: 1823 | Comments : 0
The radioisotope power sources based on the principle of the tritium beta-radiation power conversion sequentially into light and electric energy have been investigated. The spectral characteristics of used radio luminescent light sources, the spectral and electric characteristics of semiconductor photo converters have been analyzed. The experimental nuclear battery cells have been developed, based on which the battery with the short circuit current values U = 2.5V and I=1.2 µA at no-load voltage, respectively, has been assembled. The battery can be used as a power source for used household electronic devices with low power consumption.
- Counter: 1387 | Comments : 0