Archive for December 2010

Modified Sine Wave Generation With AVR

Modified sine wave is essentially just a pulse width modified square wave. It is a very useful waveform for power inverters. Compared with the simplest inverters with square waveform, inverters using modified sine wave can compensate the output voltage by simply changing the pulse width (duty cycle) of the waveform. Continue reading ‘Modified Sine Wave Generation With AVR’ »

Simple External Powered USB Port

I recently bought a TrendNet TK-207K KVM switch. After hooking up my mouse and keyboard, I was suprised to find out that the setting did not work. The mouse and keyboard would act strangely and sometimes one would stop working altogether. At first, I thought that I might have gotten a defective unit. But I quickly realized that it was a power issue — The USB port was not able to provide sufficient power to both my mouse and my keyboard. Continue reading ‘Simple External Powered USB Port’ »

4KHz-170MHz Wide Band RF Signal Generator – II

Continue with my previous article, let me first explain the code a little bit. Continue reading ‘4KHz-170MHz Wide Band RF Signal Generator – II’ »

4KHz-170MHz Wide Band RF Signal Generator – I

A signal generator can come in handy when working with digital and analog circuits. While most commercial grade signal generators offer more than just outputting a sinusoidal waveform, they are quite pricey for casual use. In this article, I will show you a simple wide band signal generator that is built around a Linear Technology’s LTC6905 Silicon Oscillator, which is can generate frequencies from roughly 17MHz to 170MHz. Along with a FairChild Semiconductor’s 74VHC4040 12-stage high speed binary counter, this signal generator is capable of generating precise frequencies from as low as 4KHz all the way through the ranges of LTC6905. Continue reading ‘4KHz-170MHz Wide Band RF Signal Generator – I’ »