| 摘要 |
PURPOSE: To obtain a power saving fan motor controller having simple circuitry which is applicable to a fan motor in a forced draft burner being driven through a switching power supply. CONSTITUTION: A variable switching power supply comprises a transformer 28 having secondary winding producing an output voltage corresponding to the conduction rate of the primary winding, an element 29 for rectifying the output from the secondary winding, and a smoothing circuits L1, C1. Output from the smoothing circuit is applied to a fan motor 51. An error detection circuit 40 detects the error between the driving voltage being applied actually to the fan motor 51 and a set voltage designated by a microcomputer 45 constituting a burner. A control circuit 30 varies the conduction rate of a switching power supply 20 in the direction for eliminating the error upon receiving an output from the error detection circuit 40. |
