Build Your Own Touch Switch Circuit – 3.3M, 1N4007

Description

Contemporary selector switches represent advancements over previous technologies. However, periodic replacements of older switches or assessments of currents exceeding specific limits, or the need for a more contemporary aesthetic, necessitate circuit modifications. For these and diverse reasons, circuit adjustments are essential. The construction of such circuits is straightforward, and the materials utilized are readily obtainable.

Circuit diagram:

Parts:

Integrated Circuits - NE555

The NE555 is a versatile integrated circuit commonly employed as a timer or oscillator. It operates based on a positive-feedback configuration, providing stable timing characteristics. This IC generates a pulsed waveform when configured as a comparator or astable multivibrator. Its wide operating voltage range (typically 4.5V to 16V) and relatively low power consumption make it suitable for numerous applications, including digital circuits and timing control. The IC contains three pins: Pin 8 (Trigger), Pin 5 (Threshold), and Pin 6 (Output). It's control and output are dependent on the applied voltage levels, and its stability relies on careful component selection and proper circuit layout.

Circuit Operation:

This circuit utilizes the well-established timer IC 555 (IC1), which drives a relay where the contacts function as a switch. The metallic components can be formed in any desired shape, yet they must remain clean and positioned appropriately within the circuit. Altering the state of the switch simply requires making contact with either metal plate – either plate MP1 to activate the contacts of RL1 [ON], or plate MP2 to deactivate the contacts of RL1 [OFF]. The current that RL1 monitors is determined by its contacts. The LED D2 illuminates when the switch is in the [ON] position and the contacts of RL1 are closed. Metallic plates MP1 and MP2 can be substituted for the metal plates. Because MP = Metal Plate.