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...
This is the analogue part of the circuite for my Arduino battery charger project.
The software can be found at https://github.com/GarethDaviesLondon/PWM-Charge-Controller-Arduino.
The pin outs refer to an Arduino Nano.
The key to this project was to make the Nano go to sleep when the sun wasn't shining.
**555 timer based PWM LED dimmer**
This project uses PWM to turn on and off a LED (or a strip of them) really fast and changes the duty cycle (Fig.1) so that the human brain perceive it as the dimming of the LED(s). This means that the MOSFET doesn’t have to drop large amount of voltage, this makes the device very energy efficient.
Using a 555 timer and a mosfet to control the speed of a DC motor with a potentiometer.
Video here https://www.youtube.com/watch?v=5nwNKPs2gco
Usando un circuito integrado 555 y un mosfet para controlar la velocidad de un motor DC con la ayuda de un potenciometro.
Video aquí https://www.youtube.com/watch?v=Q2N2OEicXJE
Universal board for LED control.
- Atmega8/328 on board with programming connector
- PCA9685 for 16 channel PWM up to 1.5kHz (eye-safe frequency), 12 bits per channel
- cheap ULN2003 with paired outputs for 1A per channel (2-3 meters of RGB 5050 strip per connector)
- or SOT23 MOSFETs if you need more power
- BT05 bluetooth module or MAX485, control by wire or wireless. DMX512 is possible.
This circuit uses the Buck/Boost Converter circuit for typically for use in a lab bench power supply. It features both adjustable voltage AND current using potentiometers.
Without a buck/boost converter,a computer power supply can only provide a 3.3V, 5V and 12 supply lines. With the buck/boost converter created with the aid of a 555 timer, adjustable voltage is allowed. A simple transistor is us...