Ready availability of cost effective components can be deployed to fabricate tilt sensor alarm in ultra transistor based simple circuit. The domestic version of tilt sensor explained here is just a simple small glass or poly bottle comprising two metallic needles penetrated through its lid containing a negligible measure of water.
One can even try through one’s own innovations to develop a tilt sensor with just a 9V alkaline battery to power the entire circuit.
Referring to the simple tilt sensor circuit diagram below, transistor T1 is generally in dormant state and on tilting the water filled sensor assembly, the needles within the sensor container are subjected to a short-circuit caused by water with the availability of positive voltage at T1’s lower part triggering to get activated. T1’s activation triggers those of T2 and T3.
For adjusting the sensitivity of circuit, preset P1 is compulsorily integrated which may be necessary if a different readily available tilt sensor is used. In the same way, SCR(T4) besides piezo sounder (BZ1)can also be substituted with close comparable parts. Resistor R3 Resistor R3 (100-150 Ohm) is not compulsory.