Two LEDs with different color (e.g., red and green), you can build a simple indicator for voltages from 4.5 to 220 V. It is also able to determine the polarity of the source in the range 8-220 V. When measuring AC voltage, both diode glow, but if it is constant — lights one of them depending on the wiring polarity indicator. The scheme proposed by the Czechoslovak journal “Amaterske Radio”.
Measure the mains voltage from 110 to 220 In a short-term need. a current-limiting resistor R1 (see Fig.). In addition to the household, the indicator is used and motorists.
Czech 1NZ70 Zener can be replaced with a tense domestic stabilization 5-6 In, for example Д815А, the diodes V1 and V5 — any low-power silicon, for example D226. LEDs can be АЛ102Б (red) and AL 102V (green).
Recommend to read
MOTOR ASSISTANT: AND WILL PLOW, AND FILM, AND GIVE YOU A DRIVE
This walk-behind tractor was not created for an exhibition - for work. In the garden, on a personal yard. In order to plow the plot, and spray the trees, and cut firewood, and transport...
AS A GIFT TO GRANDMA
Now a grandmother again took up the craft: something to mend grandchildren, and even sew new parents... Yes, that's a shame — it affects the years, eyesight not what it used to, not...
