Voltage testing

Discussion in 'General Electronics Chat' started by Interested, Feb 16, 2010.

  1. Interested

    Thread Starter New Member

    Feb 12, 2010
    Hi all,
    This is my first post so i am kind shy. As a total newbi i am still hoping to get some simple answers.
    1. How do i go about doing a voltage test to find the b+ of the flyback transformer
    2. Do each tv set have the same working voltage, and all all flybacks b+ located at the same pin?

    If i sound all mixed up please excuse me i am just trying to learn.
    thanks to all who will input.:)
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Unless there is some vital purpose in do so, it's simply not a good idea to mess with a tv CRT high voltage transformer. The frequency is high enough to support an arc over a distance of several inches. The charge in the CRT is enough to give a lethal shock.

    A special and expensive HV probe is necessary to keep any meter from being destroyed. The HV will be in excess of 25KV. You can never disturb the insulation on the flyback or the CRT lead.

    RF burns are extremely painful, and to be avoided whenever possible. It is almost impossible to poke around a flyback without hurting yourself.

    If the presentation on the CRT is normal, there is no reason to check the HV.
  3. retched

    AAC Fanatic!

    Dec 5, 2009
    Answer to (1):
    Yeah, that is a job for a well trained technician in a well equipt lab. In 11 years, I never have or had to measure the voltage on the CRT lead of a FBT. If you do not have any documentation on the component, testing it with an improperly rated probe, can kill you and burn your lab/house/building down.

    Answer to (2):
    No they do not have the same working voltages. and some transformers have different locations for input and outputs.
    Different sized tubes, require different voltages. and some specialty TVs and monitors can vary in voltages.

    Maybe you can tell us what you are trying to achieve, and we can find a safe way to get your project going.
  4. Interested

    Thread Starter New Member

    Feb 12, 2010
    thanks a lot guys