Both essentially are electrically driven hydraulic systems that begin with a reversable direction pump; both have squawt switches, indicator lights, transition light and limit switches. Both systems use positive pressure to keep the gear retracted.
The biggest difference is that the system in the PA28R-200 had the automatic extension feature; one would know a specific a/c had such by the extra "pitot" mast on the left side of the fuselage. The tubing from the mast goes to a diaphram/actuator assembly under the rear seat.
This is simply a basic overview, a proper reading of the a/c handbook is necesary to understand the entire system and all of it's components.
The manual actually does a pretty lousy job explaining these systems. This is what I remember:
Like said above, an electrically actuated reversible hydraulic pump, pumps the gear up and down. Retraction takes about 7 seconds. Extension is helped along by gravity and the centering springs.
3 uplimit switches
3 downlimit switches
Downlock hooks connect with the downlimit switches, turning off the pump, illuminating the green indicators lights and extinguishing the yellow in transit light.
Sqwaut switch on left main gear.
When gear is in auto mode, gear will automatically extend when airspeed is between 85-105 mph depending on throttle position. Also, gear will not retract below 85mph in auto mode. I always operated it in manual mode.
There is also a hydraulic pressure switch that helps to keep the gear in the up position. When the pressure in the system drops below 1800psi the switch closes and activates the hydrualic pump to pump the gear back up.
Other microswitches included that illuminate the red unsafe light and activate the gear warning horn include:
Throttle below 14" mp and gear in the up position.
Flaps extended beyond 10 degrees with the gear up.
Master switch on and gear handle in up position.
12 volt 25 amp battery
60 amp alternator
voltage regulator regulates below 14 volts
overvoltage relay takes system off line above 14 volts
Disclaimer: It has been awhile since I have reviewed these systems, although I believe the above is all correct, be sure to study the flight manual to find out for sure.
Its important to note that if there is a leak in the line the gear can possibly free fall....Which is'nt normally a problem unless that reduced range puts you overwater and running out of fuel before you reach land because of the unanticpated freefall...Also a factor in IMC x-c's etc....
Just something to think about...
It is really a GREAT gear system, no likely to fail and get stuck up because there is NO up locks.