Enlarger Exposure Meter Circuit


Posted on Jan 17, 2013

Two gates of a 4011 arc used as a comparator. When the resistance of R4 decreases the voltage at pin 1 and 2 increases, producing a logic zero at pin 3, causing pin 4 to go high and activating the LED. R3 is calibrated in light units, or seconds exposure time. To calibrate, set pot R3 so as to just be on the LED ON/OFF threshold. With a light level that is suitable to correctly expose a photographic print,


Enlarger Exposure Meter Circuit
Click here to download the full size of the above Circuit.

use a known enlarger and a known negative.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

RS-232/485 converter has automatic flow control
Dc-voltmeter
fADC Amplifier Circuit Simulations
digital room thermometer using lm35 sensor 8051 microcontroller
Simple One-Wire Touch Detector
Over-temperature alarm circuit
Universal electronic timer circuit diagram



Top