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.
To reduce the disconnection threshold of the discharge transistor /T2 is selected with a high rate of current transfer. The load (in addition to the resistor R2) and at the same time an indicator is incandescent НL with a voltage of 1 V at a current of 75 mA. In the absence of a low-voltage light bulbs a consumer may be led АЛ307Б.
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.
I have designed the metal detector works on the principle of beating is generated due to the difference of the oscillation model and tunable oscillators (5-10-th harmonic, selects the nearest frequency). This allows to increase the sensitivity of the instrument to the point that it becomes possible to detect, say, a five-kopeck coin in the soil at 10 cm, and a steel manhole or pipe — to 65-cm depth. Performed on the available element base, a metal detector does not require careful tuning and maintenance. Power supply — galvanic battery “Crown”.
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.
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.