You can only appreciate how a computer works when you know how hardware work behind the scene, as when you press the letter "a" in the keyboard, it sends a series of on and off signal called binary to the system and then converts it to equivalent matrix dots on the screen showing the letter "a", these happened just on the blink of your eye.

Computer Controlled Switch

I created this device for demonstration purpose only to the student to show how the computer can control the appliances, lights, and fan by just clicking a button on the program with in the computer. The program was created in VB6 but I used C++ to create a DLL files since VB6 cannot directly access the computer parallel port, although there are lots of line on the parallel port but I only use 2 lines which for the data and the clock, so the transmission of data is on serial style and the clock line use to sync the clock from the device and the parallel port to correctly transfer data.

Client ACSI Computer School
Skills: Electronics, Audio, Circuit board design, Relay, PC ports communication, Visual Basic, C++ DLL

I design everything from scratch, I create a logic gates tables and optimized connections using Karnaugh mapping, I used the common 74LSxx microchip, layout and itched a circuit board, during that time internet is not that easily accessible so I got all the information I need from books.

The LED indicate an active switch relay located at the back of the device, the switch is controlled digitally by the software on the computer, this device is connected to the parallel port of the computer, and hey look at that me here wearing a plain unnecessary eyeglass just to look like nerd :D, but today I really need an eyeglass.

This is the program I created to connect to the external switch device, I have uploaded the Visual Basic source code on planet-source-code website, and currently available here on Github

Speech Lab Audio Controller

This device was used on the speech lab for the student who took a subject for a Call Center course, every student has headphone and microphone connected to this device, the teacher controls which student can talk and listen, this is required as the teacher need to hear the voice of the student accurately and how they pronounce words as in simulating the call center work, aside from this hardware I created a software for it to analyze the student voice pattern that can be compared to the ideal pattern, you can check my software created section for more details of this software.

Client ACSI Computer School
Skills: Electronics, Audio, Circuit board design, Relay, PC ports communication, Visual Basic, C++ DLL

These are the cubicle for student with headset installed on it connected to the main controller on teachers desk

This is the main control panel connected to teacher computer

I used the old plastic casing of IBM computer, its plastic so its easy to drill some holes for the switches

Inside is a 15w audio amplifier with its input connected to the array of switches, the amplifier is powered by 12v DC from step-down transformer

Tagged in : Electronics

Hardware-Device Created.

Computer Controlled Switch

Speech Lab Audio Controller

Dario Mindoro