Free simple 555 timer circuits electronics projects with explanation and diagrams. Huge collection of electronics projects based on the 555 timer circuit or equivalent integrated circuits.
This negative ion generator is a high voltage generator circuit that use a 555 timer circuit to generate square-wave pulses . The square wave pulses are applied to the Q1 transistor ( Tip120 ) that provide enough current to the Q2 ( 2N3055 ) transistor to turn it on .
This 555 timer Photo alarm circuit is based on a 555 timer IC and a LDR (light dependent resistor ) .The resistance of the LDR ( photoresistive cell) varies inversely as the light intensity , the resistance is high when the intensity of light is low ( illumination level is low ) .