| 摘要 |
PURPOSE:To obtain a power source circuit having high efficiency, by connecting a relay for control with a DC power source through series resistance and connecting capacitors with the connected point of the relay for control and resistance and with one side of a DC power source. CONSTITUTION:When temp. is low and resistance value of a heat sensitive resistance element 3 is large and a comparator 2 is turned off and an output of an electronic circuit 1 is turned off, a control relay 14 is off-operated in off- operation of a transistor TR17. A capacitor 16 drops an Ac power source 9 by a transformer 10 through a resistance 15 and is charged by DC voltage V11 obtained by a diode bridge 11 and a capacitor 12, and terminal voltage V13 of the capacitor 16 becomes equal to V13 While, when temp. rises and resistance of the heat sensitive resistance element 3 becomes small and the comparator 2 is turned on and the electronic circuit 1 is outputted, TR17 is turned on and the relay 14 is grounded and a charge of the capacitor 16 is discharged. The voltage applied to the relay 14 contacts with a relay contact stably below rated voltage by the resistance 15. |
