Amateur radio also called ham radio is an awesome hobby and lots of fun. If you are already into electronics and enjoy studying radio theory than this is most likely a hobby you would really enjoy. Preher-Tech has added an amateur radio page to our website that includes basic info on amateur radio as well as a list of all the books you will need to get started in this hobby. I myself am a general class operator, my call sign is KF7LTV
and I am planning to go get my amateur extra license very soon, giving me full privileges on the amateur bands. Hope to hear some of you on the air soon. Click here to visit our amateur radio page.
Don't forget to visit www.preher-tech.com for all your electronics needs.
One of my newsletter subscribers sent me a picture of the preher-tech opto-isolator tester which he had built from the parts list and schematic I had included in my article on testing opto-isolators. He did such a great job even etching a PCB that I had to share the pictures of his work with all of you. Great job Beh!
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Take a look at this new guide by Greg Carpenter, "Introduction To Basic Electronics". This guide will get you started with all the basics of electronics the easy fun way, at home and at your own pace.
Are you looking for a guide to show you how to fix LCD TVs? If so then you may want to take a look at "Troubleshooting and Repairing LCD TVs". Whether you are a technician that is looking to expand your repair skills or just someone who has a broken TV that wants to repair it at home and avoid repair costs or replacing your TV than this is the book for you. 195 pages and only $25.00 and this ebook even comes with email support from the author John Preher. So don't hesitate to grab this guide today and start fixing LCD TVs.
An opto-isolator also called an opto-coupler or photo-coupler allows a signal to pass from one circuit to another but allows the two circuits to remain electrically isolated. The most common opto-isolator which comes in IC package consists of an LED which shines onto the base of a photo-transistor (usually an npn transistor) and allows current to flow from collector to emitter until the LED is turned off. When a signal is applied to the LED it then shines light that is varied in brightness with the same amplitude as the input signal, this light lands upon the photo-transistor (the resistance of the collector/emitter junction now changes with the varying light) which passes the signal onto the next circuit.
Basic opto-isolator symbol.
If you do a lot of work on switch mode power supplies than you have surely seen the opto-isolators used in the feed back section of the power supply.
Opto-isolators in LCD TV SMPS.
If you want to read more about opto-isolators including my 3 methods for testing them than dowload my free article "Understanding and Testing Opto-isolators" by clicking here.
Included in the article is a schematic and parts list for a simple opto-isolator tester.
Don't forget to visit http://www.preher-tech.com and also if you have any electronics related questions you can email me john@preher-tech.com for assistance.
Recommended Repair Guides:
LCD TV Repair Guide
LCD TV Repair Case Histories
