DETECTOR VIBRATIONS FOR CAMERA OBSCURE
SCHEMA ELECTRONIC SENSOR VIBRATIONS:
It is an instrument of great precision and sensitivity, realized with very modern concepts. I / element
sensitive is is a photo resistance that is able to reveal smaller changes in light thanks to two transistors Tl and T2 connected in Darlington. Vindication of dimming is performed by a series of 1 6 LEDs.
The connection between resistance and picture circuitry is printed with a cable effeclue blind. For the adjustment, you must proceed as follows:
1) Install the photo resistance in terms of the enlarger (sensitive part to haul)
2) Adjust the lens to a diaphragm of 5.6 or 8.
3) Adjust the enlarger for the maximum amplitude (maximum height). At present, adjust the trimmer Tl to the ignition point of the LED number 16. By lowering the enlarger, note the extinction of the aforementioned LED and I Ignition other depending on the distance of the light from the plane. Each LED corresponds to a number, just done the user, by precedent trials will build a table oil make it correspond to the numbers data, exposure times; and, whenever it will make prints it will have the exact indication of exposure time for any expansion.
It is to be noted that for the operations of adjustment, and for normal use of the exposure meter, insert the film in the enlarger. Laboratory tests were performed realized by using an enlarger DURST B30 model with an objective NEOTAR 1: 3.5 / 50 and a lamp of 75 watts. Remember also that you should not perform tests with different values diaphragm, because, like any amateur photographer knows, for each additional diaphragm must double the time of exposure while for each diaphragm and less time is halved. Ie device must be powered with a stabilized 12 volts ; For mounting of components, follow the scheme practical implementation carefully.
LIST OF ELECTRONIC COMPONENTS:
All resistors are
of 1/4 watt unless stated
otherwise.
R = 1 Kohm
R2 = 1 Kohm
R3 = 8,2Kohms
R4 = 560Kohms
R5 = 5,6Kohms
R6 = 39Kohms
TR1 = 4.7 ohm trimmer
Cl = 0,22uF100Vpol.
DL1 = red Led
DL2 = yellow LED