What electrical experiments can be done with an old TV?

Answer 1

Before you do anything with an old TV it is important to remember that the picture tube is connected to a capacitor that stores a very large voltage. Even if the TV has been off and disconnected for a while the charge can still be there. Touching the wrong point can be lethal.

One thing you can do without opening the case is to experiment with magnets around the screen while the TV is on. The magnets will distort the path of the electrons as they fly from the electron gun to the screen. This will make for interesting shapes and colors.

You might try connecting a rabbit ears antenna to the TV and then run it near a high tension power line to see it picks up interference on the screen or speaker.

Another thing you can do is use a prism to shine the spectrum of the sun onto the front of the screen. In some cases you will be able to see the screen glowing beyond the violet end of the spectrum. This is the ultraviolet light from the sun reacting with the phosphors in the screen.

The chassis of the TV may have several adjustment controls that the technician uses to get the color and picture correct. On really old TVs many of these controls were available on the front or back of the set where the user could fiddle with them. Newer sets have automatic adjustments and so fewer controls but there may be some inside. Again if you take the cover off be very careful not to get shocked. Technicians use special plastic tools to adjust these controls.

If you have an oscilloscope you can connect it to certain points in the TV's circuit and study the signals in their raw form. It would be best to ask a technician where to connect and also what to avoid.

One more safety note. The inside of the screen is coated with phosphors which glow when struck by the electron beam. These can be poisonous so use care not to break the picture tube and use extreme care in cleaning up if you do.

Answer 2

Cathode ray tube experiences.