Posts tagged ‘LM358’

Visualizing Comparator and Op Amp Hysteresis

Hysteresis can be added to a comparator circuit to improve its stability, especially when the input signal is noisy. In this post, we will examine the hysteresis characteristics of some common comparator and Op Amps using an oscilloscope. Continue reading ‘Visualizing Comparator and Op Amp Hysteresis’ »

An Isolated DAC Using PWM Output

Arduino‘s (ATmega328P) PWM outputs via analogWrite can be conveniently turned into analog voltage levels through the use of simple RC filters. Since the PWM outputs are not isolated, using them to drive other devices directly could be potentially dangerous. This is especially true if the target circuit uses a higher supply voltage. Continue reading ‘An Isolated DAC Using PWM Output’ »

Building a Sweep Generator for BK 4011

I did a teardown of a BK Precision 4011 5MHz function generator a few weeks ago. Like most of basic function generators in old days, BK 4011 does not offer frequency sweep as an option. What it does include is a VCG (Voltage controlled Generator) input, which essentially is just a VCO and it can be used in conjunction with an external sweep generator to generate frequency sweeps. Continue reading ‘Building a Sweep Generator for BK 4011’ »