[图文]Zone Alarm System
this is a complete alarm system with 5 independent zones suitable for a small office or home environment. it uses just 3 cmos ic's and features a timed entry / exit zone, 4 immediate zones and a panic button. there are indicators for each zone a system armed indicator. the schematic is as follows:
each zone uses a normally closed contact. these can be micro switches or standard alarm contacts (usually reed switches). zone 1 is a timed zone which must be used as the entry and exit point of the building. zones 2 - 5 are immediate zones, which will trigger the alarm with no delay. some rf immunity is provided for long wiring runs by the input capacitors, c1-c5. c7 and r14 also form a transient suppresser. the key switch acts as the set/unset and reset switch. for good security this should be the metal type with a key. at switch on, c6 will charge via r11, this acts as the exit delay and is set to around 30 seconds. this can be altered by varying either c6 or r11. once the timing period has elapsed, led6 will light, meaning the system is armed. led6 may be mounted externally (at the bell box for example) and provides visual indication that the system has set. once set any contact that opens will trigger the alarm, including zone 1. to prevent triggering the alarm on entry to the building, the concealed re-entry switch must be operated. this will discharge c6 and start the entry timer. the re-entry switch could be a concealed reed switch, located anywhere in a door frame, but invisible to the eye. the panic switch, when pressed, will trigger the alarm when set. relay contacts rla1 provide the latch, rla2 operate the siren or buzzer.
解决选择合适安全控制器的复杂性
国产耳机品牌Nank南卡重拳出击，发布骨传导耳机新标杆
苏州电感厂家科普0603贴片电感噪音产生的原因
手机处理器之外这3种配置也很重要
政策利好情况下 网络安全技术的划分会更加精细
[图文]Zone Alarm System
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记一次段码屏调试总结
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小米6难产，华为Mate9 Pro缺货，这个锅不能让三星背
each zone uses a normally closed contact. these can be micro switches or standard alarm contacts (usually reed switches). zone 1 is a timed zone which must be used as the entry and exit point of the building. zones 2 - 5 are immediate zones, which will trigger the alarm with no delay. some rf immunity is provided for long wiring runs by the input capacitors, c1-c5. c7 and r14 also form a transient suppresser. the key switch acts as the set/unset and reset switch. for good security this should be the metal type with a key. at switch on, c6 will charge via r11, this acts as the exit delay and is set to around 30 seconds. this can be altered by varying either c6 or r11. once the timing period has elapsed, led6 will light, meaning the system is armed. led6 may be mounted externally (at the bell box for example) and provides visual indication that the system has set. once set any contact that opens will trigger the alarm, including zone 1. to prevent triggering the alarm on entry to the building, the concealed re-entry switch must be operated. this will discharge c6 and start the entry timer. the re-entry switch could be a concealed reed switch, located anywhere in a door frame, but invisible to the eye. the panic switch, when pressed, will trigger the alarm when set. relay contacts rla1 provide the latch, rla2 operate the siren or buzzer.
解决选择合适安全控制器的复杂性
国产耳机品牌Nank南卡重拳出击，发布骨传导耳机新标杆
苏州电感厂家科普0603贴片电感噪音产生的原因
手机处理器之外这3种配置也很重要
政策利好情况下 网络安全技术的划分会更加精细
[图文]Zone Alarm System
瑞萨电子推出为无人驾驶汽车运算SoC而打造的摄像头视频处理电路模块
基于RFID技术和MLX90121芯片实现电子巡更系统的设计
快递太多找不到？眼神不好有遗漏？看RFID电子标签如何渗透生活日常
自动驾驶传感器中如何现在激光雷达和毫米波雷达？
7.4最新更新IC电子通信职位
LED汽车照明领域将保持快速增长的态势
荣耀8青春版并不孤独，还有这五款能“照镜子”的高颜值手机！
基于MEMS微硅传感器制程的SENSA工艺
电子元件的保质期如何影响电子设备的性能
互动式LED地砖屏的工作原理、特点及应用
晶体管共发射极电路设计
记一次段码屏调试总结
用于火灾报警的烟雾探测器示意图
小米6难产，华为Mate9 Pro缺货，这个锅不能让三星背