When testing the response of many pulse-width-modulated (PWM) systems, there's a need to independently vary a multivibrator's frequency and duty cycle. Such systems ...

Low-frequency voltage-controlled oscillators (VCOs) can be found in clocks, timers, audio synthesizers, and a variety of other applications. The VCO shown in Figure 1 is based on a simple astable ...

A free-running generator built on the standard configuration of the 555 timer can't provide a duty cycle of exactly 50%. That's a well-known fact. Fortunately, there are several ways to get around ...