Thermal ampoule for sprinkler

A thermal ampoule for use in a sprinkler, comprising:

• a hollow casing containing a heat expansive gas, the gas having a characteristic rate of expansion given heat, the casing comprising first and second closed end portions located opposite to each other, and a side wall portion formed between the first and second closed end portions;
• and
• an electrical coil located in the inside of the casing and conducting an applied current flow therethrough, wherein the electrical coil generates a selected amount of heat in proportion to the current, and the heat is transferred to the gas.

A thermal ampoule for use in a sprinkler, comprising:

• a closed hollow casing enclosing a heat expansive gas, the gas being selected to expand according to a specific amount of applied heat;
• and
• an electrical coil located in the inside of the casing and conducting current therethrough, wherein the electrical coin generates first and second amounts of heat in proportion to first and second applied currents, respectively, and transfers the first and second amounts of heat to the gas.

A method of operating a thermal ampoule for use in a sprinkler, the method comprising:

• applying a current to an electrical coil located in the inside of the thermal ampoule, the ampoule containing an expansion gas surrounding the coil;
• and
• feeding the current through the electrical coil so as to generate heat and expand the gas.