Lighting Meter | Electronic Project Circuits

Posts Tagged ‘lighting meter’

Bar graph light meter by ic 741

If you want simple meter the intensity of the light in a simple way. This circuit is very interesting, because with a LED display with 5 levels.The main equipment is uA741 the most popular op-amp circuit, to used the photo transistor is a device for receiver a lighting to change is electricity very low. We use IC1 acts boost up current, or to compare the voltage levels.The VR1 adjusts the offset voltage to the LED display complete , the intensity of light to measure.The power supply size use +9 V and -9V.

Be the first to comment - What do you think? Posted by admin - September 20, 2011 at 9:59 pm

Categories: Lighting, Meter Tags: bar graph led display, Led lighting circuit, lighting meter

Ultra-simple Voltage Probe

Detects 1.8 to 230 Volts DC or AC. This circuit is not a novelty, but it proved so useful, simple and cheap that it is worth building. When the positive (Red) probe is connected to a DC positive voltage and the Black probe to the negative, the Red LED will illuminate. Reversing polarities the Green LED will illuminate. Connecting the probes to an AC source both LEDs will go on. The bulb limits the LEDs current to 40mA @ 220V AC and its filament starts illuminating from about 30V, shining more brightly as voltage increases. Therefore, due to the bulb filament behavior, any voltage in the 1.8 to 230V range can be detected without changing component values.

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