Hello friends! Today we will study LED dimming using a 555 timer in Proteus ISIS. In our earlier single and double LED flasher and multiple LED flasher , the visible effect was a repeated change between on and off. Here we want to understand how a circuit changes apparent brightness. We will first examine the original fading demonstration, then build a controlled pulse-width-modulation example. PWM lets us change the fraction of time an LED conducts while keeping its on-state current limited. The important measurements are pulse width, repetition period and LED current. The original screenshots and download are retained. Their off, dim and bright images show the intended visual effect, but a still image cannot establish the electrical waveform. We will use the oscilloscope to distinguish a ...