Uploaded November 2015 | Updated September 2026, 3 weeks ago
A plasma ball consists of a central electrode that is surrounded by an insulating glass or plastic globe. Upon closer inspection, the electrode is made up of a system of wires - a large alternating voltage (3 - 5 kV @ 30 kHz) is applied to this electrode.
The globe is then filled with neon gas at a low pressure. The low density of the gaseous atmosphere reduces the breakdown voltage required - this means that ionisation and electrical discharge becomes relatively favourable.
The electric field generated at the electrode then ionises the neon gas, resulting in a plasma of ions. These ions provide a path for the electric current to flow, which results in the filaments in the globe. The filaments extend to only the boundaries of the globe because the globe itself is an insulator.
When we touch the globe with our fingers, we create an enhanced path to earth - this will increase the strength of the discharge, which is why the filaments seem to increase in intensity and are attracted to your hand when you touch the plasma ball.
The alternating voltage at the centre creates electromagnetic waves, and the arcs of plasma act as antennae, meaning that the extent of the electromagnetic field surrounding the ball is significantly larger than the bounds of the glass globe. Bringing the fluorescent tube near to the plasma ball allows the electrons inside to be accelerated by this field, and those moving electrons constitute an electric current, which causes the fluorescent tube to light up.
A plasma ball consists of a central electrode that is surrounded by an insulating glass or plastic globe. Upon closer inspection, the electrode is made up of a system of wires - a large alternating voltage (3 - 5 kV @ 30 kHz) is applied to this electrode.
The globe is then filled with neon gas at a low pressure. The low density of the gaseous atmosphere reduces the breakdown voltage required - this means that ionisation and electrical discharge becomes relatively favourable.
The electric field generated at the electrode then ionises the neon gas, resulting in a plasma of ions. These ions provide a path for the electric current to flow, which results in the filaments in the globe. The filaments extend to only the boundaries of the globe because the globe itself is an insulator.
When we touch the globe with our fingers, we create an enhanced path to earth - this will increase the strength of the discharge, which is why the filaments seem to increase in intensity and are attracted to your hand when you touch the plasma ball.
The alternating voltage at the centre creates electromagnetic waves, and the arcs of plasma act as antennae, meaning that the extent of the electromagnetic field surrounding the ball is significantly larger than the bounds of the glass globe. Bringing the fluorescent tube near to the plasma ball allows the electrons inside to be accelerated by this field, and those moving electrons constitute an electric current, which causes the fluorescent tube to light up.
