Among the means of self-defense e-treskovye device (ASH) – not in last place, especially the strength of psychological impact on criminals. However, the costs are considerable, which encourages radio Amateurs to create homemade analogues (detailed material about it see, for example, in No. 5,’99 the magazine “modelist-Konstruktor”.
Without pretending to sverhordinarnogo and Superviso ideas, suggest their own development, to repeat which is able to anyone who at least once in their life has dealt with the winding of the transformer and installation of simple devices like crystal radio with an amplifier on one or two transistors.
In order to obtain a sound signal of high power (10 – 20W) from the simple Assembly of a sound generator, does not require complex amplifiers WOOFER.
On the recommendation of the manufacturer to eliminate the memory effect of Nickel-cadmium batteries (NiCd) should clear their element to 0.4 V. For the implementation of the above requirements and automate the process of disconnecting the battery reaches level 0.4 V the authors propose a simple device.
Of the readers who didn’t lose metal parts or tools? Sometimes it happens at the most inopportune time and threatens to permanently stop work. Lost somewhere in the grass screwdriver that fell behind the Cabinet chisel or a failure in a pier of pliers is able to ruffle anyone. In such cases a simple device – a magnetic probe with light and sound alarm. Using this simple device, you can easily find the loss in hard to reach places and the fact findings you will be notified outbreak warning led and buzzer. The principle of operation of the probe is quite simple – on a long rod fixed two magnet “sticking” to the metal object which closes the circuit and lights the warning led. Thus, you can know when the probe with discovery, you can extract the “light”.
Security systems are a rapidly developing area of modern electronics. Published a huge number of various schemes and designs that can make anyone a couple of times was holding the soldering iron. For example, “electronic security guards” can warn of an intruder enters the premises or to signal the presence of the recorder for unauthorized sound recordings.
The formation of ice on the surface of the blades of the rotor (screw) microgenerator-ROV, wind turbines, anemometers, propeller vanes, fans, degrades performance and may lead to dangerous modes of operation – imbalance, vibration, destruction of bearings, the possibility of destruction of the structural elements is relieved by ice. To prevent such operation it is necessary to detect and eliminate incipient icing.
In large apartments and private homes in the evening and at night it is difficult to follow the dark corridors or staircases to the touch to find the button and turn the lighting.
Simple circuits sound LEDs turn on electronic devices
Buzzer on digital circuits switching on/off of electronic devices with power supply of 12 V.
The use of automotive capacitive sensor for home security.