darkroom computer tips

with a contribution from H. Fietta The many reactions to the darkroom computer described in the September and October 1982 issues are evidence of the great interest shown in this circuit. This article now describes the manner in which the darkroom computer can be connected to the well-known Philips enlargers PCS 2000 and PCS 130/150. Also shown is a method of obtaining better linearity of the thermometer, as well as an improvement to the operation of the darkroom computer by means of a small program modification. darkroom computer tips elektor january 1983 1 Darkroom-Computer 7 5V _J TIL 111 PCS150 Stand By L _ _ _ _ _J 83016-1 When connecting the darkroom computer to Philips enlargers PCS 130/150 and PCS 2000, the problem is that these units are equipped with built-in timers. There is therefore a risk that the built-in timer will affect functioning of the timer in the darkroom computer. Furthermore, these enlargers have a "power- on reset". This means that the enlarger lamp will ...