**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.
Circuit board to hold Ardunio Nano, and provide connections for RGB, IR & BLE Devices,
The aim of this project is to work with a Microcontroller to create an RGB InfiniLight, that allows for Mobile App Controll, IR Remote Control and possibly Gear Control
Based on Adam Savage's at https://www.youtube.com/watch?v=65r_1TzJXaQ#t=2850
Input voltage 13.5-36V
DC Motor controller 20A continuously
Constant voltage or RPM
Adjustable current limit
Opto Interrupter for RPM sensing
ATmega328P PID controller for constant RPM
LED driver 14-26V, 350mA, dimmable
OLED display and rotary encoder (https://easyeda.com/sascha23095123423/dc-motor-controller-panel)
MOSFET acts like a diode to protect against reverse polarity but with lower voltage drop.
The figures below are for the P-FET design. N-FET design will be similar except with minus signs instead.
1. The absolute maximum Vds should be at least -2Vbat, where Vbat is the voltage of the power supply/battery.
This is because in a situation when correct polarity rapidly switches to...
# HECA 2 - relative humidity air conditioning device for PM sensors
HECA 2 is more compact version of [HECA](https://easyeda.com/nettigo/Nettigo-Air-Monitor-Heating-Element-Control) with different enclosure.
In this design we used precise temperature and humidity sensor from Swiss company Sensirion: SHT30 (or SHT31/SHT35) connected via I²C. This sensor is equipped with programmable ALERT output....
Drives 16 mosfets with 74hc595 registers. Includes diodes to allow for inductive loads such as solenoids and motors. All parts can be placed using JLC SMT. A suitable 3.3V mosfet could be chosen with the same package as well, if you want to drive this with 3.3V on the 5V rail.
I sell assembled versions of these boards. Go to [my website](http://www.calebmarting.com/shiftdriver) to get purchasing...
# PTC Heating Element Control
In this design we used precise temperature and humidity sensor from Sensirion: SHT30 or SHT31 connected via I2C. Sensors are equipped with ALERT output. This output is connected to N-channel MOSFET and controls PTC Heating Element. Huge advantage of this design is ALERT logic which can be programmed via I2C and it's independent from main micro controller. In other wo...
- This circuit is used to control the speed of a 12V motor using a PWM signal.
- The transistors Q1-Q4 are there to invert the signal, to amplify it and to derive the voltage still present at the MOSFET at the moment of switching off. D1 and R6 also serve this purpose.
- D2 terminates the induction voltages of the motor.
- C1 and C2 keep the voltage supply stable.
- MP1 measured against G...