These fields are typically low-frequency and mimic the natural electromagnetic fields produced by the body. 

PEMF therapy is used in various medical and wellness applications. It is commonly employed for pain management, wound healing, and bone-related disorders. In addition, this type of therapy improves sleep, mental focus, and the body’s overall performance by helping the energy output and regeneration of the body’s cells.

  In several of my previous videos, I described different ways to make such devices yourself, because commercial ones are too expensive. After the request of several of my viewers and readers I decided to develop and make this project which is actually a miniature portable magnetic pulser that is powered by a battery and you can take it with you everywhere. And again, not to mention brands, such devices are sold at a price of 100 to 300 dollars and more. Even this device is also more advanced than the commercial ones and is controlled through a Smartphone application. We can set many different frequencies depending on the type of therapy we want to apply.
     Basically this is a miniature PEMF device and produces a magnetic field of approximately 1 Gauss. 

 I should also mention that according to NASA research, fields of 0.5 to 4 Gauss are sufficient for effective therapy. I tried to make the device as simple as possible, so that even those with less experience in this field can make it. That's why I used ready-made modules, which, in addition to excellent functionality, also have an incredibly low price.

   The entire device contains only a few components:
     - a small DFRObot Bluetooth amplifier module model XY-WRBT
     - lithium, or better lithium polymer battery (also you can use miniature power bank connected directly to micro-usb port)
     - a small coil that radiates an electromagnetic field
     - and a miniature switch to activate the device
    First, let me describe the components in more detail:
   - This small bluetooth amplifier module is actually the main part that wirelessly receives signals from the smartphone software, amplifies that signal, and sends it to the coil that radiates this signal in the form of an electromagnetic field.

 - The module is powered by one lithium or lithium polymer battery, and can be charged with external charger, which is a great option and allows us unlimited inexpensive use of the device. I mention this because commercial devices use a standard, usually 2032 type of lithium battery which, when used up, needs to be replaced with a new one.

  - And the coil that radiates the electromagnetic field. It can have a shape that depends on the box or the shape in which the device is created, but most often it is round or rectangular. It is made with thin lacquered copper wire with a diameter of 0.1 mm or thinner and should contain at least 100 turns or more, which is not critical.

 I specifically used wire from an old relay and the coil consists of 150 turns. When making this coil, we should pay attention to some recommendations, such as: Its ohmic resistance must not be less than 15 ohms, and that it should contain 100 or more windings. If we use a thicker wire, the resistance will be lower, the field will be stronger, but the battery consumption will be higher, and vice versa. That's why we need to find some compromise between field strength and consumption, so I recommend you to use the coil I made.
  First, we need to install some free Signal Generator Application on the smartphone, and I specifically use "Frequency Sound Generator" from "LuxDeLux" wich is free app. 

   A few words about Smartphone application. All the options are available on the start screen, the frequency is marked in the middle, which we can set using the slider or enter it manually. Let me just mention that the frequency can be set with a huge accuracy...