Here is an attempt of development of Contact-Less Sanitizer Dispenser without using microcontroller.
This development is done using an IR Led and IR Photo-transistor as pair of sensor whose output is fed to Op-Amp to compare it with the reference voltage and the output of Op-Amp is driving the transistor as a switch to turn on Load which is 3v - 6v submersible pump in this case.
So the device will simply push out the sanitizer as long as sensor is blocked by the hand within certain range.
[center]
[/center]
[center]
[/center]
Here is the Schematic.
[center]
For more clear view you may downlaod pdf.
WSD_WoMCU.pdf (25.0 KB)
Here is the PCB Layout.
[center]
[/center]
Here is 3D Board.
[center]
[center]
[/center]
This circuit can be improved further and other features can also be implemented, so looking forward for the participant to come up with other iterations/versions.
Lets discuss.
Happy Exploration!