Oscilloscopes are commonly used to observe the exact wave shape of an electrical signal. In addition to signal amplitude, oscilloscopes can show time distortion between two events (such as pulse width, period, or rise time) and relative timing of two related signals
Below is a picture of common Oscilloscope.
Today, Oscilloscope uses LCD color display, displaying better graphics
Step 1: Make Your Own Oscilloscope Using Your Laptop Computer
Once I need an oscilloscope to see the electrical voltage ripple in the car. Ignition systems, alternator rotation, high-beam lights flicker, and others are generally emit noise or voltage ripples, Well, this is what I want to know, size of the noises, etc.
Oscilloscopes are very expensive tools, and generally are only used in electronics / electrical laboratory.
Finally, I found an application that could use laptop computer / PC as Oscilloscope by adding some components as interface.
Those components are simple and quite cheap!
The necessary components:
• Two 22K ohm Resistors
• Two 82K ohm Resistors
• One 50K Linear Potentiometer + Tuning Knob
• One meter Shield Stereo cable
• One 3.5mm Stereo Jack
• Tester Terminal
Step 2: Electronic Scheme
• The 22K Resistor serves as voltage safety limit into laptop soundcard.
• The Potentiometer serves as input voltage resistor. If the voltage is above 5volt, adjust the potentiometer necessarily to prevent the soundcard from being damaged by excessive voltage input.
• Use shield audio cable to prevent induction around the cable.
Step 3: The Probes
Step 4: Testing
Plug the Stereo Jack into LINE-IN/MIC
Get OSCILOSCOPE APPLICATION
The application is ZELSCOPE, free download at www.zelscope.com .
This application is 14-day Trial, could be purchased at a price of not more than (US $9.95).
The Oscilloscope is ready for use!!
Below are several voltage signal tests, among others signals from mobile phone charger, laptop charger, battery, etc.
Sample of close-to-perfection voltage signal without noise.
1. This Oscilloscope could be used for a maximum input voltage of 5Volt.
2. This Oscilloscope has a frequency range of: 20Hz to 20 kHz (complying with the Soundcard capability).
3. The value of 22K Resistor could be increased up to 820K Ohm for the use of Oscilloscope with an input of above 5 volt.
4. The value of Potentiometer could be increased up to 100K Linear, for the use of Oscilloscope with an input of above 5 volt.
5. For safety of your Laptop, you can use cheap USB SoundCard (under $5).
Translated by Taufik Masjhur
This post was originally published on saft7.com in Bahasa Indonesia language.