Do@Ho
PROJECTS
Water Leak Detector (Project 1)
Summary
In this video we show you how to build a simple water leak detector at home. We used simple components and materials such as: buzzer, aluminum foil, sponge, and tape to make the sensor structure. Let us know what do you think about this project.
How to Make it?
Cut a piece of sponge and soak it in the brine. Completely dry the sponge until it gets relatively hard. Cut two strips of aluminum foils and tape them on the sides of the sponge. Make a simple circuit using a 9V battery and buzzer and this sensor as a switch. The sensor is ready to use. After detecting the water, the buzzer starts sounding. To reset the sensor just dry the sponge!
Important Notes
In this video we show you how to build a simple water leak detector at home. We used simple components and materials such as: buzzer, aluminum foil, sponge, and tape to make the sensor structure. Let us know what do you think about this project.
How to Make it?
Cut a piece of sponge and soak it in the brine. Completely dry the sponge until it gets relatively hard. Cut two strips of aluminum foils and tape them on the sides of the sponge. Make a simple circuit using a 9V battery and buzzer and this sensor as a switch. The sensor is ready to use. After detecting the water, the buzzer starts sounding. To reset the sensor just dry the sponge!
Important Notes
- The best buzzer is the one that can turn on by 3V and will not get damaged by 9V
- The buzzer has + and - leads, Connect it correctly
- A better tape that does not degrade by water is recommended to be used
- You may use a glue, epoxy, or an enclosure box to shield the entire sensor
How Does it Work?
Detecting the water, normally needs analog electronic circuits including operational amplifiers or at least a transistor because the conductivity of the tap water is not high enough to conduct the current needed to turn on a buzzer. Brine increases the conductivity of the water; so, there is no need for additional circuits. When the sponge is soaked in the brine and dried, it has dried salt in it. When in operation, a small amount of water can solve the salt and conduct the current.
DIY VLF Metal Detector (Project 2)
Summary
In this project we show you how to make a simple Induction Balance (IB) Very Low Frequency (VLF) metal detector. We used simple components and materials such as: Buzzer, Copper PC Board, Battery, Wire Coil, Hot Glue, and Super Glue. Let us know what do you think about this project.
How to Make it?
Shape the cardboard using a scissor or sharp knife. Shape the PC board for battery bottom connector. Apply a thick layer of super glue on the surface of cardboard to make a hard structure for battery holder. Place the bottom plate and battery holder, let the super glue to dry. Open the buzzer and remove its diaphragm. Solder two wires to the buzzer and solder the other end of the wires to the battery holder leads. Solder the receiver coil to the headphone jack and solder the capacitor in parallel with that. Position the receiver coil and headphone jack; then, hot glue it. Finally, hot glue the buzzer. Connect the Headphone and Insert the battery to turn on your Metal Detector.
In this project we show you how to make a simple Induction Balance (IB) Very Low Frequency (VLF) metal detector. We used simple components and materials such as: Buzzer, Copper PC Board, Battery, Wire Coil, Hot Glue, and Super Glue. Let us know what do you think about this project.
How to Make it?
Shape the cardboard using a scissor or sharp knife. Shape the PC board for battery bottom connector. Apply a thick layer of super glue on the surface of cardboard to make a hard structure for battery holder. Place the bottom plate and battery holder, let the super glue to dry. Open the buzzer and remove its diaphragm. Solder two wires to the buzzer and solder the other end of the wires to the battery holder leads. Solder the receiver coil to the headphone jack and solder the capacitor in parallel with that. Position the receiver coil and headphone jack; then, hot glue it. Finally, hot glue the buzzer. Connect the Headphone and Insert the battery to turn on your Metal Detector.
How to Adjust it?
While listening to the beep sound on headphone, displace the receiver coil next to the buzzer until the beep sound fades out. Mount all components in that position using Super Glue.
Important Notes
- The best buzzer for this project is the one that has a higher frequency. Higher frequency results better sensitivity and detection depth
- The buzzer has + and - leads, Connect it correctly
- The capacitor improves the sound quality, not a very critical component for this project. Use a 100nf ceramic capacitor
- To make the receiver coil, wind 500 turns of 42 AWG magnet wire around a 40mm diameter spool
- It results better if you use a thicker magnet wire. However, the size of the receiver coil will be larger
- You can make the spool using a small piece of thin cardboard. If You have a 3D printer, print the spool STL file provided below.
- Use a high impedance headphone. The headphone jack has 4 pins: Left speaker (L), Right speaker (R), G (Common Ground), and Microphone (M). Solder the receiver coil to L and R pins to achieve the maximum impedance. Do not use G or M.
- You can use a low-cost headphone amplifier to amplify the output, resulting better performance.
How Does it Work?
An IB metal detector has a transmitter coil and a receiver coil. The transmitter coil, continuously sends an ac signal with several KHz frequency (or tens of KHz frequency for gold detectors) and the second coil, receives the signal. In general, an oscillator circuit, transmitter coil, receiver coil, and amplifier are required.
In this project, after removing the diaphragm of the buzzer, we use it as an oscillator and transmitter coil. It significantly simplifies the structure of the metal detector. The high frequency noise in the receiver coil is filtered by a capacitor and the receiver coil drives the headphone.
Coil STL File