Jaltron's main method for cooling is via an external air pump shown here for the Cooled Tadpole Coil. However, non cooled coils are smaller and easier to hold. Non-cooled Tadpole Coil is shown as a comparison next to the cooled version. Many Jaltron coils have a built-in 1" diameter ball joints for mounting on coil arms.
Figure of eight coils can be small for superficial stimulation such as the Double 30mm Verta Coil for rodent stimulation. They can also be large for deeper yet focal stimulation such as the Cooled Curved Double Coil for cortical stimulation.
Single winding circular coils can be small for superficial stimulation such as the Circular 40mm Coil for facial nerve stimulation, or dual side by side stimulation. They can also be large for deep stimulation of lumbosacral nerve roots such as the Circular 20cm Mats coil.
Coils can be non-cooled where they are smaller, lighter and can still perform fine for limited number of stimuli. They can also be cooled using built-in quiet fans, such as the Cooled Octo Coil shown here. Same type of cooled and non-cooled coil have the same winding and hence the exact same output.
Different coils of the same type are a compromise between depth of penetration, discharge click noise, size, and how fast they heat up. Shown here are the Double 37mm and Double 55mm MRI coils with the latter having approximately 50% greater depth of penetration.
Figure of eight coils are set up such that the fields from windings add for normal and active operation. However, where needed, the wiring can be reversed for a sham version such that the magnetic field in the center to cancel out leaving only the peripheral stimulation from the distal ends. This can either be done by supplying two identical looking coils as shown here, or via a selector switch.
Stimulating coil windings are typically spiral bound and made from insulated copper. They come in many shapes and sizes for different applications. Some examples are shown above. Clockwise starting from top left: (a) Small figure of eight coil with each winding having a mean diameter of 30mm useful for primate and rodent work, (b) standard figure of eight coil for human use with each winding having a mean diameter of 60mm, (c) single circular 40mm coil, (d) quad butterfly coil for increased focality, and (e) Angled D-shaped figure of eight coil for deeper penetration.