Aircraft initiators are controlled electronically by components called heated bridgewires. Bridgewires are thin resistance wires that set off pyrotechnic compositions. They typically use fuel and oxidizer solutions called pyrogen to promote material ignition.
Bridgewires are compact, lightweight and designed to optimize overall output and efficiency. They function similarly to detonators and blasting cups without producing shock waves. Instead, they create pyrotechnic compositions using exothermic chemical reactions.
Bridgewires reach high temperatures through the exchange of electrical currents. This heat initiates the attached substance’s exothermic chemical reaction. After the bridgewire fires, it melts and creates an open circuit.