US 11,982,247 B2
Load drive device
Koichi Tsukio, Hitachinaka (JP)
Assigned to HITACHI ASTEMO, LTD., Hitachinaka (JP)
Appl. No. 17/772,968
Filed by HITACHI ASTEMO, LTD., Hitachinaka (JP)
PCT Filed Oct. 20, 2020, PCT No. PCT/JP2020/039323
§ 371(c)(1), (2) Date Apr. 28, 2022,
PCT Pub. No. WO2021/085226, PCT Pub. Date May 6, 2021.
Claims priority of application No. 2019-195626 (JP), filed on Oct. 28, 2019.
Prior Publication US 2022/0412281 A1, Dec. 29, 2022
Int. Cl. F02D 41/20 (2006.01); H03K 17/12 (2006.01)
CPC F02D 41/20 (2013.01) [H03K 17/122 (2013.01); F02D 2041/2093 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A load drive device comprising:
a drive switch that turns on or off a current supplied from a power source to a load;
a switch drive circuit that transmits a drive signal to the drive switch based on a control command from an arithmetic device; and
a constant current source that supplies a current to the load without passing through the drive switch,
wherein the switch drive circuit includes a voltage monitoring circuit connected to monitor a voltage difference between both ends of the load and determine whether the voltage difference is equal to or less than a predefined value,
wherein the switch drive circuit performs control so as not to supply current from the constant current source to the load when the drive switch is turned on to supply current to the load, and
wherein the switch drive circuit performs further control so as not to turn on the drive switch when a voltage difference between both ends of the load becomes equal to or less than the predefined value in a state where the drive switch is turned off and where a current is supplied from the constant current source to the load.