Abstract: The exothermic instrument for firing an explosive comprises a circuit board 1 having a heat resist layer 6 on a substrate 11 and an exothermic resistance 4, which connects to a pair of through hole conductive electrodes 13 passing through the substrate 11, contacting with the explosive 19 on the heat resist layer 6, a pair of electrode pins 8, each one thereof is inserted into each one of the through hole conductive electrodes, and an insulator for holding the circuit board 1 through which the electrode pins 8 pass.

Abstract: A gas generator for an inflatable life raft having a gas-generating chamber filled with a gas-generating composition which generates gas by chemical reaction, either a chemical cooling chamber or a physical cooling-and-filtering chamber or both, a gas passage in communication with a safety valve, and an ignition device which provides rotational friction between a friction means and a frictional igniting agent. The gas generator has the advantages that it is not influenced by the environmental temperature, a gas temperature drop due to adiabatic gas expansion accompanying the gas discharge does not occur and therefore the generated gas can very reliably be discharged, the gas is fully cleaned, troubles due to abnormality of the gas-generating composition can be avoided, and it can be made light and small.