How to build a one-time anti-theft alarm system
How to build a one-time anti-theft alarm system The purpose of this alarm is to sound the alarm only once. That is-when the alarm is activated-the sound siren will be in the preset length of time. Then it will close and stay closed. The alarm will not restart. The basic alarm has an independently adjustable single entry and exit delay zone. This area will accommodate the usual types of normally open and normally closed input devices-such as pressure pads, reed contacts, micro switches, aluminum foil tape, and PIRs. The extension module of the range allows you to add any instant alarm area, area and personal attack tamper zone to the system. There is also a non-timed output module. It will make an internal sounder, strobe light, light or siren after it goes to stop. schematic diagram The alarm can be hidden by a simple operation of the two-way switch-such as a light switch. If you want to know more about security-you can use a key switch-or a numeric code to operate the keyboard switch. After setting the alarm-to ensure that the building is safe-that is, the green LED lighting are all-this yellow LED is off. If the yellow LED lighting-there is one in the wrong area-and the alarm will not be set. When you move to the "Settings" position of SW1--Different settings regarding R9, you can leave the building for up to about a minute. When you return and open the door-the buzzer will sound. The settings for the Audi R8 are different-you still have about a minute and the alarm switch is turned off. If you do not do this-Siren will sound. Depending on the settings of the R14-the audible alarm will take up to about 20 minutes. Then it will close-and stay closed. Of course-you can stop the noise of moving SW1 to the "off" position at any time. When you return-if the buzzer is not sound, yellow LED lighting-then there is activated while you are away. schematic diagram Parts List This article comes from the electronic enthusiast website (http: //), please indicate the source
The retractable earphone is a type of earphone cable that can be freely retractable and free to control the earphone cable as needed. The principle of this earphone design is to inject liquid gallium indium alloy into the elastic polymer tube, which can be normally conductive and free to stretch. When you need to use it, take out the earphone cable and start using it. When you use it, you can retract it. After retracting, the overall volume is small, it is particularly convenient to carry, and there is no trouble with the winding of the earphone cable.
Retractable Earphones,Retractable Headphones,Retractable Wireless Headphones,Retractable Bluetooth Earphones Shenzhen Linx Technology Co., Ltd. , https://www.linxheadphone.com
