Circuit substrate and electric oil pump

Patent metadata

Field	Value
Publication number	US-2020313517-A1
Application number	US-202016797082-A
Country	US
Kind code	A1
Filing date	Feb 21, 2020
Priority date	Mar 29, 2019
Publication date	Oct 1, 2020
Grant date	—

Abstract

An electric oil pump includes a control substrate including a reverse connection protection circuit to protect a circuit in the substrate, a first substrate wiring connected to a source terminal of a MOSFET in the reverse connection protection circuit, a second substrate wiring connected to a GND terminal, and a bypass circuit that causes a current to flow from the first substrate wiring to the second substrate wiring in a case in which an output voltage of the external power supply is equal to or greater than a predetermined value that is greater than a rated voltage, in which the predetermined value is a value that is smaller than a withstanding voltage between a gate and the source of the MOSFET.

First claim

What is claimed is:

1 . A circuit substrate comprising:
a substrate; a positive terminal and a GND terminal to which a DC external power supply is input; a reverse connection protection circuit that includes a MOSFET and protects a circuit in the substrate in a case in which positive and negative connection of the external power supply to the positive terminal and the GND terminal is reversed; a first substrate wiring that is connected to a source terminal of the MOSFET; a second substrate wiring that is connected to the GND terminal; and a bypass circuit that causes a current to flow from the first substrate wiring to the second substrate wiring in a case in which an output voltage of the external power supply is equal to or greater than a predetermined value; wherein the predetermined value is smaller than a withstand voltage between a gate and the source of the MOSFET.

2 . The circuit substrate according to claim 1 , further comprising:
a third substrate wiring that is connected to the gate terminal of the MOSFET; wherein the bypass circuit includes a Zener diode and a resistor electrically interposed between the first substrate wiring and the second substrate wiring and connected to each other in series; the Zener diode is electrically interposed between the first substrate wiring and the third substrate wiring; the resistor is electrically interposed between the third substrate wiring and the second substrate wiring; and a Zener voltage of the Zener diode is lower than the withstand voltage between the gate and the source of the MOSFET.

3 . The circuit substrate according to claim 1 , further comprising:
a third substrate wiring that is connected to the gate terminal of the MOSFET; wherein the bypass circuit includes a varistor and a resistor electrically interposed between the first substrate wiring and the second substrate wiring and are connected to each other in series; the varistor is electrically interposed between the first substrate wiring and the third substrate wiring; the resistor is electrically interposed between the third substrate wiring and the second substrate wiring; and a varistor voltage of the varistor is lower than the withstand voltage between the gate and the source of the MOSFET.

4 . The circuit substrate according to claim 2 , further comprising:
a first test point that has electrical continuity with the first substrate wiring; and a second test point that has electrical continuity with the third substrate wiring.

5 . The circuit substrate according to claim 3 , further comprising:
a first test point that has electrical continuity with the first substrate wiring; and a second test point that has electrical continuity with the third substrate wiring.

6 . The circuit substrate according to claim 2 , further comprising:
an electrolytic capacitor; and a motor drive circuit; wherein the electrolytic capacitor is electrically interposed between either of the first substrate wiring or a fourth substrate wiring that is connected to the first substrate wiring via an electronic element downstream of the first substrate wiring and the second substrate wiring; and the motor drive circuit is disposed downstream of the electrolytic capacitor.

7 . The circuit substrate according to claim 3 , further comprising:
an electrolytic capacitor; and a motor drive circuit; wherein the electrolytic capacitor is electrically interposed between either of the first substrate wiring or a fourth substrate wiring that is connected to the first substrate wiring via an electronic element downstream of the first substrate wiring and the second substrate wiring; and the motor drive circuit is disposed downstream of the electrolytic capacitor.

8 . The circuit substrate according to claim 4 , further comprising:
an electrolytic capacitor; and a motor drive circuit; wherein the electrolytic capacitor is electrically interposed between either of the first substrate wiring or a fourth substrate wiring that is connected to the first substrate wiring via an electronic element downstream of the first substrate wiring and the second substrate wiring; and the motor drive circuit is disposed downstream of the electrolytic capacitor.

9 . An electric oil pump comprising:
a pump; a motor that drives the pump; and a circuit substrate; wherein
the circuit substrate includes a motor drive circuit that drives the motor unit; and
the circuit substrate is the circuit substrate according to claim 6 .

Assignees

• Nidec Tosok Corp

Inventors

• Seki Yusaku
• Sekiguchi Chisato
• Takao Junichi
• Konagaya Yasuaki

Classifications

• H02H7/09

  against over-voltage; against reduction of voltage; against phase interruption · CPC title

• H02H7/0827

  responsive to underload or no-load, e.g. pump-off control circuits for pump motors · CPC title

• H02P25/16

  characterised by the circuit arrangement or by the kind of wiring · CPC title

• H02H7/08

  for dynamo-electric motors · CPC title

• F04C2/08

  of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing · CPC title