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    2022

  • 2022-10-29
    Analyzing Circuits Using the Espotek Labrador: Measuring Servo Control

    Where I demonstrate different methods of measuring a servo pulse to ensure it meets requirements.

    Introduction

    In the entry on servos I discussed the specific pulse requirements to make a servo move. In a nutshell, a servo needs a positive pulse .5ms to 2.3ms in a 60Hz signal. Or to put it another way, it requires a 60Hz signal with a duty cycle ranging from 3% to ~14%.

  • 2021

  • 2021-06-17
    Comparing the Labrador

    Where I compare the Labrador with the $300 Digilent Analog Discovery 2 and determine if using a “rail-to-rail” operational amplifier matters.

    Sources

    • LM358 Datasheet
    • OP484 Datasheet
    • Analog Devices Op Amp Inputs, Outputs, Single-Supply, and Rail-to-Rail Issues
    • Texas Instruments A Single-Supply Op-Amp Circuit Collection

    Research

    This video, Rail to Rail Op Amps P1 got me thinking as to the issues with the LM358. So to determine if it mattered on my previous amplifier design, I went back and redid the circuit. I used the OP484, as it was an op-amp I had and it is specifically a “Precision Rail-to-Rail Input and Output…”. I thought it would be interesting to do two things:

  • 2021-05-16
    Analyzing Circuits Using the Espotek Labrador: Filters

    Where I explore filters in electronics and use the Espotek Labrador to demonstrate how to understand filters and create amplitude response curves. This discussion will be absurdly simplistic in comparison to the topic. My goal is to show sufficient theoretical examples of filters, so we can then test them using the Labrador.

    Video: How to Use the Espotek Labrador to Analyze a High Pass Filter Amplitude Response Curve

    Our goal with the Labrador is to test the following filter analysis. Doing so will help make electronics more intuitive and familiar and help you understand as to how to use the Labrador. It will also help you understand how to plot data and in this case, using a log scale.

  • 2021-04-01
    Op Amp Resources

    Here are links to Operational Amplifier information, primarily for the design of simple, practical amplifiers.

    • What is an op amp?
    • How To Bias An Op-amp
    • Avoiding Op-Amp Instability Problems In Single-Supply Applications
    • Three op amp instrumentation amplifier circuit
    • Operational Amplifier Circuits
    • Basic Two Op Amp In-Amp Configuration
    • The Instrumentation Amplifier

    Tutorials

    • Introduction to Operational Amplifiers
  • 2021-03-31
    Analyzing Circuits Using the Espotek Labrador: Programmable Bias and Gain

    Using potentiometers for programmable bias and gain on the amplifier.

    A Typical Problem

    If you followed the last couple of experiments, AC Signal Analysis and DC Sweep, you know you have a functional amplifier that will take either a DC level or AC signal and amplify it -2.5x. How do you know this? You were able to test the amplifier using the Labrador’s built-in Signal Generator.

    This is nice, if that is the only signal you want to amplify. However, that isn’t the point of electronics! We want to explore and use our amplifier to amplify unknown signals! We want to put it to use!

  • 2021-03-27
    Designing an Inverting Amplifier with Bias

    I’ll use this amplifier to perform multiple tests using the Espotek Labrador.

    For more information on using operational amplifiers, I encourage you to look at these sources:

    • What is an op amp?
    • MAS.836 HOW TO BIAS AN OP-AMP
    • Avoiding Op-Amp Instability Problems In Single-Supply Applications

    Simple Operational Amplifier Discussion

    Simple op amp figure
    The operational amplifier (op amp) is defined by two rules:

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