W2UHI hydraulic dish elevation system notes
3/19/01
1. Basic concept and fabrication courtesy K2AH
2. Application implementation W2UHI
3. Refer to hydraulic and or electrical schematics
for the following notes:
A. Solenoid valves are one way only, closed when not energized. They
are connected in PAIRS,see both schematics for details.
B. Rate of movement is controlled by orifices
inserted at the cylinder ports,according to system requirements.
C. Pressure relief valve adjustment is made to
begin bypass when the cylinder reaches it's maximum extremes. I arranged
the mechanical range to be 3 degrees to 70 degrees, this eliminated the
need for limit switches.
D. The pump motor runs on 90 VDC. I switch the primary of the motor pwr supply to minimize dc arcing on the relay contacts. The UP and down relays have two sets of contacts, one pair to run the motor and the other to operate the solenoid valves. The motor only runs when motion is required. Switching the primary also provides a soft start and stop, this minimizes surges when commanding movement. Frank
