| 摘要 |
#CMT# #/CMT# The circuit has a regulated power supply whose output is connected to an input of a limiting device (2). The limiting device includes shunt voltage limiters i.e. Zener diodes (D1-D3), and a current limiter i.e. fuse (F1), to the direction of intrinsic safety. The power supply has a current regulator (3) delivering a constant current (Ir) on the input of the limiting device, so that the voltage limiters form a voltage regulator. The limiting device has a resistor (R1) limiting transient current. #CMT#USE : #/CMT# Power supply circuit for an intrinsic safety apparatus that is installed in an explosible environment i.e. near natural gas conduit. #CMT#ADVANTAGE : #/CMT# The power supply circuit ensures optimized output power equivalent to explosive atmosphere (ATEX) protection, ensures protection against short-circuits by the selection of the current value and utilizes standard components with reduced cost. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a simplified block diagram pf a power supply circuit for an intrinsic safety apparatus. D1-D3 : Zener diodes F1 : Fuse Ir : Constant current R1 : Resistor 2 : Limiting device 3 : Current regulator. |
