electrohydraulics Flashcards
what are the two categories of electrohydraulics
electrically controlled systems and electronically controlled systems
why are electrically controlled systems considered to be high voltage
because they use full battery voltage to control the system
what is a discrete solenoid
on or off
when troubleshooting for electrical faults what should you check first
battery voltage
relays
reduces control circuit current flow
solenoids
creates the force required to operate hydraulic components
wiring harnesses and connectors
used to connect the system components and carry current flow
control switches
provides means for the operator to initiate system operation
the main disadvantage of electrically controlled hydraulic systems is that they are not able to
provide variable speed control
what is the function of the bucket kick out on a wheel loader
hold the bucket control lever in the roll back position until the bucket reaches the correct digging position
when the detector plate is in close proximity to the bucket kickout switch the switch is
closed
loader bucket kickout position and lift height can be adjusted by
adjusting the position of the proximity switch in relation to the detector plate
what is the function of input devices in a electronic controlled system
to send information in the form of electrical signals to the ECU
what is an example of s discrete reference voltage sensor
a switch
lever operated potentiometers that are used as operator controls are called
joysticks
what are two types of joystick configurations
single and dual axis
what is the function of a clamping diode
to dissipate the current flow created by inducing voltage in the solenoid coil when the operating switch is opened . preventing arching damage to the relay
what is one of the main difference between electronically and electrically controlled systems
electronically controlled systems utilize less than full system voltage
microprocessor
is a device that takes information sent to it from input components and compares it to parameters established in an internal memory
what are the two categories of input devices
reference voltage sensors and voltage generating sensors
what are the two types of voltage generating sensors
rotating permanent magnet and reluctance voltage generator
what is hysteresis
when a directional control spool requires more current on one end than the other to move the spool
what is one way to control hysteresis
with dither
what is dither
constant vibration of a spool to allow for easier start movement of the spool
