NEW POSSIBILITIES OF OLD TRANSFORMER

WHAT'S NEW OLD TRANSFORMER

Adjusting household autotransformer ARB-250 I bought in the beginning, as they say, the days when it cost only 16 rubles. Immediately, without looking at the manual and connecting to the device no load “kerf” their purchase to the grid…

The outcome of such hasty actions are burnt because of improper installation of the adjusting drive and the fuse went on the decline mood. The latter in no small measure contributed to clarified in the course of repeated (correct) fact: really a valid adjustment from ARB-250 is far from what was expected.
 
Autotransformer is irrelevant. The emergence of modern radio and television equipment (with integrated voltage regulators) and even threatened him with resignation. But then came “electric shortage”. In an effort to facilitate the operation of its 75-watt table lamp and prolong its service life, I did not succumb to the temptation to solder something more contemporary, tyrestore-triac. Remembering ARB-250, I began to think, how to adapt this autotransformer.
The resulting circuit diagram is shown in figure. And for comparison next given the same. Immediately catches the eye is the main difference between the new designs from the old: the inclusion of the autotransformer as if backwards, with two options for switching the “common” wire to the input of another element of the switch SA1.
 
Old ARB-250 with new features
Old ARB-250 with new features:
 
1 – autotransformer standard housing, improved; 2 — voltmeter on the led matrix, full-time; 3 disc extended within flexible parameters adjustment; 4 — cord network.

 
Schematics: a — initial; b — modified.
Schematics:
 
a — initial; b — modified.
 
All work for alteration ARB-250 takes (verified personally) not more than 10 minutes. This is mainly the cost of installation rocker switch TV2-1 and isolation of the former, marching on load removal. But what was the result! To connect to such a transformer-wagon now almost any household appliance — user alternating current power supply voltage almost from “scratch” and up to 250 V. Good, in particular, to apply a modified ARB-250 for receiving “soft”, “muted”, and then gradually changing (as in cinema) the light from a sconce, a table lamp or floor lamp. When the need arises, I use the auto-transformer as power source for my homemade 40-volt soldering iron and other “non-standard” loads.
 
Do yourself a similar device based on ARB-250 — you will not regret!
S. KONDUKOV, Krasnodar

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