Electronics-Lab.com Blog

Creating some blinky LED lights for Christmas has always been on my wish list. Last Christmas season I really started thinking about building something. My first thought was, each LED lamp could simply be connected to a pair of wires. The power to the LED lamps could be an AC signal that would sweep from a low frequency to a high frequency.

Designing a Multi Node LED PWM Lamp – [Link]

This is a simple circuit for DC Motor speed control (fan speed control, light dimming and etc) using the 555 timer. Also a good starting point for novices wanting to get their hands dirty with the 555 timer IC. Some would argue that this is not the most efficient approach.

Simple and dirty PWM For Motor Speed Control – [Link]

The schematics for this DC/DC converter is built around the UC3843 generic, low cost PWM controller. This very common PWM controller generate a duty-cycle modulated square wave ranging from 0 to 100%, at a user fixed frequency of 100KHz.Here are some features: [via]

• Input voltage from 10V to 18V
• Output voltage from 20V to 28V adjustable
• Output current up to 5A for 3300mAh battery packs fast charge.
• Compact dimension (80×60mm)
• No heat sink or fan coolers even delivering up to 140W to the load.

High power 24V DC/DC converter - [Link]

This circuit can be used as an amplifier to switch on and off a DC motor and to regulate its spinning speed with a PWM source generator. [via]

An amplifier for Arduino - [Link]

The circuit is very simple. The RGB LED is hooked up to the PWM outputs on PORTB1 , PORTB2 and PORTB3 of the ATMega8. There is also a resistor between the LED and the ATmega8 to limit the current to 20mA. There is also a link to the datasheet of the RGB LED that is used in this project.

The code for the fading LED is written in assembler with the AVR Studio 4. In this example the LEDs will fade in and out one by one. The PWM timers of the ATMega8 are used to let the LED’s fade in and out. To use the PWM timers you first need to initialize the timers at the begin of the program code. The speed of the fading in and out can be changed with changing the clock speed of the ATM8.You can copy and paste the textfile into the AVR Studio 4. [via]

Fading RGB LED with PWM Control - [Link]

This is versatile development board for AVR microcontrollers ATmega48/88/168. It is good for testing and debugging embedded programs. It has many built-in peripheries connected to microcontroller so you can use them without soldering. ATmega microcontrollers are produced by ATMEL and they include a lot of features: I/O, Timers, PWM generators, ADC, RS232, TWI, SPI, Analog Comparator, Oscillator, EEPROM These microcontrollers are very versatile, easy to program and easy to use. This is the reason why I like these microcontrollers and why I decided to make development board for them.

ATmega48/88/168 Development Board - [Link]

Light an LED, Power a motor, this simple – ish circuit will accommodate all you constant current needs using NE555 chips! This is a great way to learn about electronics and although not as efficient as using a pre made buckpuck, this is more fun, cheaper and hopefully you’ll learn something too! [via]

Constant Current Power Supply using Pulse Width Modulation - [Link]

A second USB servo controller. This one extends Ronald Schaten’s USB-Servo to 6 servos with a separate supply. It was designed to control the servos of a robot. This device was designed to control standard hobby radio control servos via a PCs USB port. Standard RC servos need a power supply of between 4.8 and 6 volts. They also have a Pulse Width Modulation (PWM) signal input which controls the angle of the servo. This device supplies up to 6 such servos with a 5V supply and the PWM signal to control the servo.

USB-Servo 2 - [Link]

All out of TO-220’s? Thinking maybe you can eke enough performance out of a smaller transistor?

Want to squeeze a bit more current through those inexpensive TO-92 package transistors? Then add a small metal heatsink. I made this for a PWM DC motor driver, as some 2N2222 bi-polar transistors were handy. Of course, we should only operate components within their factory spec, but it’s good to know this type of desperation has been previously explored – just in case. [via]

DIY TO-92 heatsink - [Link]

Rob sent in the latest gadget freak, he writes -

Seeing great potential in a normal, off-the-shelf product, Pete Griffiths designed a circuit he popped into the lamp to give it a new lease of life. His design combines a PIC and three constant current buck converters to create the RGB LED controller. This controller drives the high power 350mA LEDs using PWM to control the LED brightness. By driving the red, green and blue LEDs with varying pulse widths the controller can generate up to 16 million colours using fades, strobe and static effects. Who says you can’t give the humble lamp a nip and tuck? [via]

RGB LED PWM Driver for High Power 350mA LEDs - [Link]