This circuit is a digital sound level meter with a LCD screen, capable of displaying 80 characters (4 rows with 20 characters on each). You can build this LCD display. It also provides more debugging information, such as the minimum and maximum analog-to-digital samples that were measured during each period. [via]
Digital Sound Level Meter - [Link]
This invention is not so new but so I took the liberty of posting my symple version, based on IC 4093. With that, I hope no one more is surprised by the lack of water in the water tank, just as I was.
Water tank’s level visualization – [Link]
This liquid level sensor measures the capacitance of the liquid between two electrodes and gives an indication of liquid level inside a bottle. Capacitance is measured by charging the capacitor and measuring the time needed to discharge via a known resistor. The brain of the sensor is an Arduino board.
A capacitive liquid sponsor relies on the fact the the capacitance or charge between 2 metal plates will change (in this case increase) depending on what material is between them. This allows us to create a level sensor that is save for use with any liquid, this one will be used in a buggy with gasoline
Building a Capacitive Liquid Sensor - [Link]
The heart of this project is using PIC16F88 to determine the water level by calculate the relation of water level and the water capacitance.A simple probe can be made using insulated wire. The insulation is then the dielectric of an cylindrical capacitor with the inner conductor as one plate and the water as the other. The probe is not suitable for distilled or very pure water because it is not conductive enough. It works well even in relatively clean water such as roof runoff water in a plastic tank. [via]
Digital water level meter project - [Link]
Water Level Buzzer is a simple kit which will buzz when water reaches the sensor level.
- Input – 9 VDC @ 40 mA
- Output ??? Buzzer
- Terminal pins for supply voltage
- Power-On LED indicator
- Four mounting holes of 3.2 mm each
- PCB dimensions 32 mm x 35 mm
Water level buzzer - [Link]