This circuit makes use of a pickup system that in modern times can be an optical fiber. The transistor is a general-purpose type and the sensor is an LDR. The power can be from 6 to 12 V depending on the relay. R is 1M ohm.
This circuit makes use of a pickup system that in modern times can be an optical fiber. The transistor is a general-purpose type and the sensor is an LDR. The power can be from 6 to 12 V depending on the relay. R is 1M ohm.