Position: Index > Electrical Circuit >

EXPOSURE_INDICATOR_FOR_ENLARGER

2014-11-16 11:54  
Declaration:We aim to transmit more information by carrying articles . We will delete it soon, if we are involved in the problems of article content ,copyright or other problems.


EXPOSURE_INDICATOR_FOR_ENLARGER
One leg of Wheatstone bridge is unbalanced by light shining on phototube. Sensitivity of circuit is adjusted to match speed of enlarging paper with potentiometer that changes d-c voltage applied to phototube. Meter can be calibrated directly in seconds of exposure -J. Markus and V. Zeluff, Handbook of Industrial Electronic Control Circuits, McGraw-Hill, N.Y., 1956, p 291.