| 摘要 |
FIELD: tool-making industry, possible use for protecting enclosed spaces. ^ SUBSTANCE: in accordance to the invention, registration of changes of aerial flow is performed in enclosed space constantly on basis of change of speed and/or temperature of air flow, and indication of signal is performed on basis of amplified signal of temperature sensor at frequencies below 50 Hz. Intruder alarm contains temperature indicator with first and second sensitive elements, amplifier, comparator and indication block. Both sensitive elements of sensor are included in bridge circuit, outputs of which are connected to input by bridge unbalance amplifier, output of which is connected to comparator, which produces signal for ensuring operation of indication block. Temperature indicator contains a sensitive element in form of two heat-variable resistors, positioned in the body and means for connecting sensitive element to measuring block. Body is divided on two sections by a wall, where one of sections is made with walls which allow passage of air flow, and other section - with walls, which do not allow passage of air flow. One heat-variable resistor is positioned in each section. ^ EFFECT: expanded functional capabilities, increased speed of operation, simplification and reduction of costs of manufacture and operation. ^ 3 cl, 3 dwg |
