Simple circuits sound LEDs turn on electronic devices
In Amateur practice, it is frequently necessary to announce the inclusion of any homemade or industrially produced household electronic appliance, equipment or device — which is unusual, pleasant to the ear (if picked up a soft tone audible signal). This is especially true when the appliances operated with a remote control — an acknowledgement signal confirms that the received command. For example, when the operation control of air conditioning — when it is turned on or the mode is changed as a response to user, sound short and melodious sound signal duration of 1 — 2 seconds.
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.
This device is designed to automatically turn on exterior lighting after dark, and, accordingly, the automatic switch-off at dawn, which is always important, especially in terms of country of residence in order to save energy resources.
“Ah, summer red, I would love you, if not for the heat, and dust, Yes mosquitoes, Yes flies”. And although the high poetry of the great poet little combined with the dry prosaic lines, technical articles, these words can be safely put as the epigraph to this material. To stop the change of seasons in nature is impossible, and every year we have a “happening” summer, and with it come the usual worries of relief and localization of negative emotions, invariably manifested in humans with the appearance of annoying flying insects — mosquitoes, flies and other midges. To protect yourself from them, in nature and even at home someone buys a mosquito net, others treat themselves and family members with special insect repelling creams and formulations. However, possessing the skills, you can build a simple circuit protection device against mosquitoes, operating by using of ultrasonic radiation. What is ultrasound?
A power transformer is to convert alternating current of one voltage to alternating current of another voltage at a constant frequency. The device in the normal “classic” transformer all know from school physics lessons. The principle of operation is based on electromagnetic induction. In the primary winding under the action of tension in the core induces a magnetic flux proportional to this voltage, which, in turn, an electromotive force of self-induction (EMF) in the secondary windings is directly proportional to the number of turns of these windings.
For connecting various electronic and household devices designed for a constant voltage of 9, 12 or 15 V, requires adapter (the adapter from the network 220V). Usually every device it sells.
This is a safety alarm device (SLD) is designed to automatically alarm (electrozone) in the case of penetration of unauthorized persons in the protected object — an apartment, dacha, garage. It is more immunity and no false positives. The unit is powered by 12-volt battery GB1 of the eight cells that consume standby current less than 5 mA.