发明名称 |
Overload protection circuit |
摘要 |
The overload protection circuit 12 comprises a resistor bridge 20 with a low impedance sensing resistor r and high impedance resistors R1 to R4 which generates voltages Va and Vb at the inputs 32 and 34 of a comparator 22. Voltage Vb depend upon the value of the load current so that the comparator provides at its output 36 a control signal for opening the switching device 24 comprising a field effect transistor when the load current exceeds a maximum value. Resistor R5 reinforces the effect of the control signal. This circuit can be used in a system which comprises a central power supply unit 8 which powers a plurality of devices such as 4. The status of the circuit 12 is reported to the system 8 though line 14 and circuit 12 comprises a control circuit 26 which is responsive to set and reset control signals on lines 14 and 18 from the unit 8 to close or open the switch 26.
|
申请公布号 |
US5299087(A) |
申请公布日期 |
1994.03.29 |
申请号 |
US19910731593 |
申请日期 |
1991.07.17 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
FERMIER, YVAN;FERRY, MICHEL;JACQUART, CHRISTIAN;VACHEE, PIERRE |
分类号 |
G06F1/30;H02H3/08;H02H3/087;H02J13/00;(IPC1-7):H02H3/093 |
主分类号 |
G06F1/30 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|