HAU & HAD Application Notes

 

HAU Single Analog Driver:

DUAL COIL DRIVING JOYSTICKS WITH TWO HAU VALVE DRIVERS
When a dual coil driving joystick is to be used to control 2 HAU valve drivers, a filter is
required to convert the joystick's PWM output into a voltage that will control the HAU's.

 

HOW TO USE THE HAU VALVE DRIVER WITH A TWO SPEED SWITCH
When it is desired to have the valve switch between an adjustable preset value and "full
speed", wire in a SLOW switch as shown above. Note that the "fast" current will be
about 10% higher than the highest current that can be obtained in "slow" mode.

 

USING THE HAU DRIVER TO SWITCH BETWEEN ZERO AND A DESIRED CURRENT
When it is desired to have the valve switch between zero current and an adjustable preset value,
wire in a ZERO switch as shown above.
Open the ZERO switch to for "high" current and close it for zero current.
The 10K resistor can be 10% or better, higher wattage is OK, and can be of any construction.

 

USING A SWITCH TO DRIVE TWO COILS
To switch the valve between two different coils, wire in a coil selector switch and diodes
as shown above.

 

HAD Single Analog Driver:

HAD Connection Diagram - Two Joysticks

 

How to use a HAD Valve Driver with a Reverse Switch
When it is desired to have a control pot and a direction switch to control dual valves, hook up a
switch, a pot and a resistor as shown in Figure, 1 below. The direction switch determines which
coil will be driven. The pot determines how much coil current will flow. Coil A will be driven for
the FWD direction, and coil B will be driven for the REV direction.

 

How to use a HAD Valve Driver with Preset Outputs for Forward and Reverse Operation
When it is desired to have the valve switch between both coils off, a preset value for the A coil,
and a different preset value for the B coil, wire in a Single Pole Triple Throw switch and two 10K
Potentiometers.