| 摘要 |
<p>PURPOSE:To obtain an electric boiler of a high efficiency at a stable temperature and pressure, by providing a control device which controls the duty factors of pulse control signals corresponding to the outputs from sensors that detect the temperature and pressure in a pressure vessel. CONSTITUTION:After amplified by an amplifier 9, the output from temperature detector 4 provided on a steam delivery pipe 1d is transmitted to a control circuit 10. Information on a specified temperature set by a setter 11 is recorded on the control circuit 10 which carries out a comparison of the temperature detected by the temperature detector 4 with the specified one. In case the detected temperature is lower than the specified one, the duty factor of the pulses issued from a pulse generator 8 is raised to increase the average period of time of power supply to an induction heating coil 3, and in case it is higher, the duty factor is lowered. The electric circuit 10 regulates the intermittent flows of high-frequency electric current from a high frequency electric source 6 through an intermittent circuit 7 by regulating the duty factor of pulses issued from the pulse generator 8. Thus, this allows a quick responsible and accurate controlling of induction heating with the indication heating coil 3.</p> |
