Joining device and method for manufacturing joined object

A joining device, comprising:

• a first circuit in which a primary-side winding of a first transformer and a first capacitor are connected;
• a second circuit in which a primary-side winding of a second transformer and a second capacitor are connected;
• an electrode connected to a secondary-side winding of the first transformer and a secondary-side winding of the second transformer, the electrode being configured to sandwich an object to be joined;
• and
• a charge switch configured to switch between presence and absence of supply of electric power from a power supply to the first capacitor and the second capacitor without the primary-side winding of the first transformer and the primary-side winding of the second transformer being interposed, the power supply supplying electric power to the first circuit and the second circuit,
• wherein the first circuit has a first discharge switch configured to switch between an energized state and a de-energized state, the energized state being a state in which a current caused by energy stored in the first capacitor flows through the first capacitor and the primary-side winding of the first transformer in the first circuit, the de-energized state being a state in which the current caused by the energy stored in the first capacitor does not flow through the first capacitor and the primary-side winding of the first transformer, and
• wherein the second circuit has a second discharge switch configured to switch between an energized state and a de-energized state, the energized state being a state in which a current caused by energy stored in the second capacitor flows through the second capacitor and the primary-side winding of the second transformer in the second circuit, the de-energized state being a state in which the current caused by the energy stored in the second capacitor does not flow through the second capacitor and the primary-side winding of the second transformer.