Circuit detectors and sensors based electronics projects
Circuit detectors and sensors based electronics projects like: metal detectors circuits, smoke detectors circuit, water detector circuit, light detector and other based sensors projects.
A very simple Lie detector circuit can be build using few common components .The function of this lie detector circuit is based on the variation of the skin resistance that is used to vary the frequency of a tone oscillator . The contact rings can be two bars rings , about ¾ “ .This lie detector circuit can be powered using a 9 volts DC power supply or a battery .
This fluid level detector circuit sensor is based on a simple common 741 op amp IC used as an comparator . When that two fluid level sensor( can be used two pieces of small PCB or some conductors ) are not placed in liquid the output voltage from the 741 op amp is negative and the T1 is blocked resulting a 0 volts voltage on the R5 resistor .
