Photo sequence programmer

#This invention relates to the photo sequence programmer, particularly for use in automatic control of machines.

#The present invention provides the structure that multiple light-emitting elements are disposed inside a rotary transparent cylinder and multiple light-receiving elements are disposed outside the said cylinder so that a couple of light-emitting element and light-receiving element accurately may face each other with the said transparent cylinder wall between them.

#The adhesive opaque tape is attached in parallel on the surface of the transparent cylinder in accordance with a predetermined time chart so that the revolution of the transparent cylinder causes multiple photo-electric conversion switching circuits which consist of the said light-emitting elements and light-receiving elements, to turn ON and OFF. Each switching circuit includes a load control element in the form of a triac or a relay which is connected in series with the load which it controls or energization from the AC power supply.

#These and other objects, features, and advantages of the present invention will be readily apparent from the following description and appended claims taken in conjunction with the accompanying drawings wherein;

#FIG. 1 is a photo-electric conversion switching circuit using silicon photo diode;

#FIG. 2 shows a transverse cross-sectional view of the assemble of the photo sequence programmer;

#Referring now to FIG. 1, there is shown a typical photo-electric conversion switching circuit for the photo sequence programmer of the present invention.

#Light-emitting diode LED and silicon photo diode SPD are secured to face with each other so that light emitted from LED is projected to SPD. Anode of SPD is connected to base of NPN transistor Tr.sub.1 while cathode thereof is grounded, a point intermediate base and anode is connected positive DC source through resistor R.sub.1 and also is grounded through capacitor C.sub.1. Collector of transistor Tr.sub.1 is connected to positive DC source through resistor R.sub.2 and also to base of PNP transistor Tr.sub.2 through resistor R.sub.3 and emitter of transistor Tr.sub.2 is connected to gate G of triac T through resistor R.sub.4, while collector of transistor Tr.sub.2 is grounded together with emitter of transistor Tr.sub.1. Triac T is connected in series with load L across AC terminals.

#The operation of the circuit is such that when light from LED is projected to SPD a voltage is created between anode and cathode of SPD. Then, transistor Tr.sub.1 is reverse biased and therefore Tr.sub.1 turns OFF and its collector voltage increases up to the positive source. Therefore no base current flows through transistor Tr.sub.2 which then turns OFF, and triac is put to its OFF state.