Dual power supply with digital control

This is another great power supply project. It uses a center tapped transformer, so two choice of two channels is obvious. One channel produces positive 0 to 30V another negative from 0 to -30V. It also has adjustable current limit from 0 to 10A. Variable voltage part is used from his previous simulations. They are similar for positive and negative sides.   Controlling is performed by using Atmega328p microcontroller. Instead of potentiometer there are couple DACs used MCP4821. Microcontroller allows setting precise current limit and voltage. Updated information is displayed on LCD screen. And of course it is always good idea to add constant voltage regulators. Kerry added 12V, -12V and 5V that may be used right away without any settings. Continue reading

Crossbar – The Fantastic DIY 4×4 LED Matrix

If you always have the intention to build a fantastic 4×4 LED Matrix, then you might want to check out this Crossbar! Well, this Crossbar is a very easy project, especially for those who involving with LED Matrix frequently. The Crossbar is based on a PIC16F628A. Although this chip cannot directly control the 16 lines necessary for an 8×8 matrix, but it’s more than enough to control the 4×4 matrix! One frame on a 4×4 matrix is only 16 bits or equivalent to 2 bytes, while a frame for an 8×8 matrix might require 8 bytes, which is 4 times of the 4×4 matrix did! If you want this Crossbar to be viewed by everyone, then you have to figure out the way to solder the LEDs at the intersection of each one. It’s better not to use the steel to hold the LEDs, as it easily rusted and has trouble holding onto the solder. By the way, you don’t need to use the LM7805 or any capacitor, if you applied a regulated power supply onto this project. Good luck… Continue reading

Into The New Dimension World with Triangular LED Animation

Any Star Trekkies here? By the way, have you went to the cinema and watched the Star Trek, The Movie yet? No matter you’re the Star Trek’s fan or not, you will still love this Triangular LED Animation, as this stuff is very futuristic and ‘3D’ enough! For your information, this project is based on the PIC16F628A and Simple LED Animation Kit with the combination with red/green LEDs arranged in a triangle. The three sides of the triangle are fully-connected in parallel form. In this case, the PIC16F628A is controlling only six bicolor LEDs while the other 12 LEDs are individual elements. Between the triangular arrangements, it’s possible to create a large number of different animations. Hence, the animation sequence takes 10 minutes to repeat. Before you’re getting started, you should think and plan wisely about the design, especially the white board for your PCB. This step is to eliminate any unwanted consequences while you’re building this Triangular LED Animation. By the way, you need to apply a regulated power supply into the project. However, if you can’t find any… Continue reading