This project is a small automatic cooling system for home theater rack. It supports 2 temperature sensors for different zones in the rack and 2 12V PWM fans (standard for PC case cooling).
There is a power switch connector for a switch mounted on the casing (will be designed and 3D printed later). A reset button is provided mostly for reprogramming purpose. There are 4 buttons for setting up temp...
An Arduino Micro based automatic plant watering system.
1. Capacitive soil moisture sensing
2. Configurable minimum and maximum soil dryness setting
3. Water overflow sensing
4. Reservoir water level sensing
5. ESD protection on external sensors
6. Reverse and over voltage protection
7. Over current protection
Auto PTT on signal (useful for digital modes like RTTY / PSK / FT8).
This project is an automatic line-level audio switch.
It has 2 line-level inputs and 1 output.
When there is no signal on input 1, input 2 will be on the output.
When a signal is detected on input 1, the relais will switch the input 1 to the output.
Then when there is no signal on input 1 for about 15 seconds, the relais will switch again to input 2.
This is a simple circuit powered by a 741opamp. The relay does the switching of the pump or adapter of the water pump. It's a 230V/12V switching relay. Here you can find the schematic and the PCB layout also.