Title:
POWER UNIT
Document Type and Number:
Japanese Patent JPS55121512
Kind Code:
A
Abstract:
PURPOSE:To protect a load from an abnormal voltage by stopping the supply of a constant voltage output to the load by opening a switching circuit according to the result of a comparison between the output voltage of the switching circuit and a reference voltage. CONSTITUTION:When AC power is applied to terminal 32, relay 44 is driven by a charging current to capacitor 43 only in start operation to make contact 54, thereby supplying the constant voltage output to terminal 69. Further, comparator 61 is applied with a divided voltage of the constant voltage output and a reference voltage across Zener diode 47 and when the constant voltage output is normal, relay 55 operates to make its contact 57. Similarly, relay 56 also operates to make its contact 58. Then when a short circuit is formed across a load to lower the constant voltage output, relays 55 and 56 are reset to break contacts 57 and 58. Furtheremore, if the constant voltage output would increase up to a high voltage, neither comparator 61 nor 64 generates any output and contacts 57 and 58 are similarly broken.
Inventors:
TANIDA WASABUROU
Application Number:
JP2834779A
Publication Date:
September 18, 1980
Filing Date:
March 12, 1979
Export Citation:
Assignee:
TOKICO LTD
International Classes:
G05F1/56; (IPC1-7): G05F1/58
Domestic Patent References:
| JP50058245B |