Appeared in stores digital multimeters seriously pressed the usual “switches-instrument Toolkit”. However, expensive components (the battery), and sudden circuit failures limit the possibility of using these multitesters. And in the field-conditions, they are generally unsuitable, as ranked by now outdated “respectable” turnout isometry: danger drop, break, drop solder, the difficulty in retaining “the weight” during the measurements all lead to the loss of an expensive device. Therefore it is better to make a special microtester that meets the stringent requirements of the work in “field” conditions and convenient as a wrist watch. Well base and a “measurement head” of a homemade can, in particular, become familiar to all and accessible indicator of the recording level, is widely used at the time in designs of transistor tape recorders domestic production.
WRIST TESTER
Why “multichronic”? Because this welding transformer (CT) has many important additional functions. If in traditional “svarochnik”, which has a magnetic core assembled from P – and sh-shaped plates, sometimes nowhere to squeeze at least one or two auxiliary coil, the proposed torus, a doughnut shaped design of the free space was enough. In the end, he is capable of AC/DC to cook “five”, and batteries to charge and metal melting, feeding safe voltage elektrovyzhigatel in circles “Skilful hands”, and perform a host of other things. Fit even to put the question differently: and what a winding and for what purpose wants to additionally have the user of this ST?!
As in the previously published the console, the installation of its new version is “Welt” printed circuit Board foil fiberglass 83x35x1,5 mm. Used resistors — MLT, the capacitors C1 — C3 — MBM, C4 — C50-12; switch БВ1 — toggle П1Т-1 (or any other, preferably from among small-sized counterparts). Coil 1.1 — call from the telephone or homemade (10,000 turns of PEV-0,08 on a cardboard frame cross-section 12×8 mm with cheeks 21×21 mm, at the distance of 26 mm from each other); its DC resistance is 1.7 kω.
As you know, galvanic elements, batteries, accumulators and many generators do not have high-efficient, fast trigger protection against short circuits (a short circuit). No its in most sources of the secondary power supply Fuse the fuse, there is not in the bill. First, because the response time, is often absolutely not suitable for modern equipment, instantly reacting to abnormal situations. Second, fuses are one-time protection devices, requiring replacement by a new after his burnout, not everywhere and not always acceptable.
In many electrical devices the old issues (for example, ampervoltmetry Ts20, Ц4315, etc.) as an internal power source used battery KBS (L,X), sedss,7-4,1 In, unfortunately, which are currently very difficult as the industry is almost not released. This situation makes the owners of such devices to switch to other batteries, even of different denomination — to have the necessary EMF through a variety of their compounds, as they say, a trick.
The device allows you to monitor the status of the galvanic cells and batteries: it measures the voltage under a nominal load. Diagram of the device is a voltage divider made from resistors. Using the B1 resistors are switched in pairs: one acts as the load, and the second determines the sensitivity of the device.
To call to his subordinate, the modern Manager doesn’t need to pick up the phone, and even more — to get out of his office. Just press the speakerphone button intercom “Director — Secretary”, say a brief “invite to me…”, and no, that is, problems.
You enter the room, and suddenly light flashes, “alive” is a radio or a tape recorder. To make such a “miracle” the strength of the capacitive relay (the diagram in the figure).
allows you to quickly verify the health of the quartz resonators. Diagram of the device consists of a generator (T1), detector (D1, D2) and DC amplifier (T2). By connecting the quartz to the two terminals of the generator, the power on. If the resonator is OK, resistor R2 appears to the high-frequency voltage which is then fed to diodes D1, D2 for detection. Highlighted in this case a constant component opens the transistor amplifier stage. Load UPT serve milliammeter ИП1 and lamp L1. The glow lamp indicates the functionality of the quartz. But his activity is judged by the readings of the milliammeter. For the active resonator current is 70-90 mA, and for inactive — 30-40 mA.
There are electric circuits of high voltage sources for aeroionizatora, which are collected on the basis of the automotive ignition coil. They are all quite simple and easily repeatable. However, the cost of the ignition coil is very high.