ULF bass reflex on one first transistor. Numerous calculations and experiments to create powerful high-quality low-frequency amplifier has led me to believe that the most promising way to the design is to use a phase inverter on one first transistor. It is curious that such amplifiers could be forty years ago, but this has not happened due to a number of reasons.
Ham radio
TWO BIRDS WITH ONE STONE
For several years Samsung cell phones are available with the new universal (multi-function) mini-connector. Compact and flat (see photo), it provides charging from the adapter, connecting headphones, connecting to USB port of personal computer (“data cable”) to operate the phone as a modem and many other features.
THE TILES RESCUED… IRON
Happened that my electric “Rossiyanka-2” went out on one of the switches controls the degree of heating burners. So much so that no restoration is not subject. A suitable replacement for him even in a repair shop not found. Rescued… the thermostat of the burnt iron. However, had a bit to accommodate this, tuscawilla in storage, site.
BRIGHTER AND SMOOTHER
Industries is not only “pedal” means of transportation and sports equipment to strengthen leg muscles. In the right hands it is easily converted into a variety of small-scale mechanization, as “modelist-Konstruktor” has repeatedly been told on its pages (№ 11’81, 3’85, 2’87, 7’96). And therefore development, are addressed to cyclists — and fans of night riding with brightly burning (alternator) spotlight, may be useful to other readers.
THE OUTLET IN THE CARTRIDGE
In order not to keep the additional wiring to connect the auxiliary electrical appliances at work using portable lamps, enough cartridge “carrying” to install a homemade adaptor as shown in the figure. For the manufacture of the adapter is used the lighting cartridge, in which are drilled three holes: one in the bottom under peeled from the glass and glue the cap the blown bulbs and the two side under the plug. Before you glue the base with epoxy resin in the bottom, it is soldered from the inside of a flexible insulated conductor with a length of 45 — 50 mm.
ANTENNA GOOD RECEPTION
It often happens that the collective TV antenna is not working properly. In our high-rise building, for example, to take a high-quality image with such antenna only one TV channel. At other rescues antiquated room, which involves, unfortunately, a number of disadvantages.
A SOLDERING IRON WITH A SYRINGE.
Anyone, even a well-equipped modern machine shop to do probably without soldering. And no matter how they fought for the engineering is still in front of us (according to the definition of “Explanatory dictionary of the live great Russian language” V. Dahl) — “iron of different types, in a wooden clasp which is kindled, and, holding it across the metal and tin solder first.”
BACKLIGHT HOUSE NUMBERS
Lighting house number and street name in rural areas – is not an empty whim, but a basic necessity. In dark time of day the postman will be able to deliver a telegram, and RAM service come to the rescue. This is especially useful when the backlight lights up automatically at dusk and does not require human intervention. To make such a device might, perhaps, everyone is familiar with the basics of electrical engineering.
WELD DC
Advantages of welding machines DC before they “perimentally brothers” is well known. It’s mild arc, and the ability to connect thin-walled parts, and less spatter, and the lack of nepreverjenih sites. Even the annoying (and, as it turned out, bad acting people) cod is not. And all because there is no major inherent to the welding apparatus of the alternating current feature — intermittent arcing at the overflow of the sinusoid of the supply voltage through zero (Fig.1).
THE SOLDERING OF THE RESISTOR
I recommend readers of the magazine is easy to count, easy to manufacture and very reliable electric soldering iron. At my house, for example, these range from “krohotulki” for work with microelectronics to powerful “ax” with which to patch a leaky metal tanks, repairing wells, filters and other large items. Moreover, the heating element of each electrical device is… the appropriate power resistor (type PE or PEV), powered by household outlet voltage is 220 V. the resistance, if they cannot be avoided, reactive, precise, capacitive, allowing to solve very complex electrical problem with the minimum dimensions of the devices.
