ELECTRONIC CONTROL DEVICE

PURPOSE:To provide stable lightness of a display part under a first load without being influenced over energization control for a second load by a method wherein energization for a first load composed of the display part and the second load other than the display part is varied and a form of display control under the first load is varied in response to energization control state for the second load at the control part. CONSTITUTION:A high voltage circuit 12 for a magnetron 4 is connected to a plug 11 connected to a commercial power supply through a relay switch 13. A blower 5 is connected to it through a relay switch 14. In addition, a DC power supply circuit 15 is connected to it, a DC voltage DC1 is applied to a display tube 10 and then displaying can be carried out. DC voltage DC2 is applied to a micro-computer 16 so as to enable various controls to be attained. DC voltage DC3 is applied to a relay coil 18 connected in series with a transistor 17, and DC voltage DC4 is applied to a relay coil 20. At this time, display lighting time is varied in such a way as the applied DC voltage DC1 energized from the same power supply circuit 15 is in reverse proportion to value of a load, resulting in that brightness in displaying at the display tube 10 becomes stable.