It is known that in the process of operation of car batteries is required from time to time to do preventive charge-discharge cycles to prevent sulfation of the plates and thereby increase their service life. There are lots of devices, including homemade (see the journal “modelist-Konstruktor” No. 9— 11 ’01), through which the battery is initially discharged to 10.5 V with a current of 1/20 of its capacity and then the voltage on the terminals is communicated during the charge-discharge cycle to 14.2 to 14.5 V. And the ratio of the charge-discharge current components are in the majority supported almost perfect — 10:1, and the pulse durations of the charge-discharge — as 3:1, but…
AUTOMATIC BIT-CHARGER
Busy with household chores or interesting conversation, we forget, for example, on a boiling kettle. Time to remind him maybe a simple buzzer. However, the oscillators sound frequency (e.g. multivibrators) based on transistor logic or integrated circuits do not always meet their creators. The simplest devices give a smooth tone, barely visible against the background of everyday noise, and sudden and loud “beep-beep” of a more complex designs can scare.
We offer homemade household heat stabilizer can be used in incubators, dryers, fruit, mini-greenhouses etc. From existing analogues it is original schematic construction, maintaining the temperature with an accuracy of ±0.1 °C, tolerance with fluctuations in the AC 160 to 240 V, and can operate from a DC source with voltage up to 310 V. the Power regulated heater element can reach 750 watts.
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needed for anyone who is keen on constructing of measuring equipment and equipment for radio control models. Simple circuit universal wavemeter, shown in figure, is a conventional crystal radio set, whose output is headphones included the arrow measuring device ИП1 with the DC amplifier transistor T1.
Hams know how sometimes when soldering they do not have a third hand to fix a small detail. At the time it was proposed many devices that can help in such a situation (see, for example, the magazine “modelist-Konstruktor” No. 10’1996). In particular, I use a fixture, which is made in just a few seconds.
Informing about the occurrence of an event, people often use sound signals. Usually they have the character of a continuous sound “one note” annoying “beep-beep” or howling siren with a periodically varying frequency. Generators of electric vibrations, producing these signals is also straightforward. They are based on one-two multivibrators, which makes the structure very simple, accessible to even beginners repetition hams.
Summer — time for vacation and travel. During this period, there is a special need for a universal power supply for various mobile (and not only) household appliances.
Seed stations and seed agro-laboratories often calculate “manual. Manual labor is unproductive and tedious, especially if you need to count a large number of seeds. Counting on 10 thousand grains of wheat takes about three hours. And to make a mistake during manual account easily. However, this operation can be replaced by a method of weighing, but due to the difference in sizes of the seeds of error in this case reaches 30%.
A lot of interesting instruments created in radio school of the Gomel Palace of pioneers and schoolchildren named after V. I. Lenin. Here are some of them: pulse the flash and the instrument for testing high-power transistors developed by members of the group Valery Denisenko and Sergey Skruzny.