| 摘要 |
<p>PURPOSE:To make it possible to put a relay into operation in response to the break of wire of a heating element, temperature relay and electric conductor by connecting the heating element and relay in series and by feeding electricity to them from the electric power input terminal of a fluid driver. CONSTITUTION:A voltage of a fixed value is applied between terminals X and Y of electric blower 11 and as far as the series circuit of heating element 7 and relay coil 12A is normal, relay contact 12B is closed. At this time, as the radiation fin of heating element 7 increases in temperature, this radiation fin is cooled by a cooling wind from blower 11 since it is arranged in an air duct. After the cooling wind in the air duct stops, the temperature of the radiation fin rises and exceeds the set temperature of temperature relay 8, and consequently its contact is opened, cutting off electric power feed to blower 11. Then, contact 12B of relay 12 is opened and the circuit is opened between terminals C and D, thereby detecting the velocity of the wind in the air duct being below a fixed value.</p> |
