Logarithmic light-meter circuit


Posted on Mar 28, 2013

The meter reading is directlyjproportiona! to the logarithm of the input light power. The logarithmic circuit behavior arises from the nonlineardiode pnjunction current/voltage relationship


Logarithmic light-meter circuit
Click here to download the full size of the above Circuit.

The diode in the amplifier output prevents output voltage from becoming negative (thereby pegging the meter), which may happen at low lightlevels due to amplifier bias currents. Rl adjusts the meter full-scale deflection, enabling the meter to be calibrated.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Dc motor speed control 2
12V 50W Switching Regulator by UC3844N
power supply variable with lm338
Auto Shut Off Tone Generator
gps altimeter
Electronic Stethoscope
IC Multiplexers
The STA013 MP3 Decoder Chip
Free Energy Schematic
Light control delay circuit 4
Seven blinker circuits



Top