Dual voltage regulator

[Pete Somers]

Hi all

Can anybody help me to locate a dual voltage regulator for the electric trim on the 400A A/P, P/N C611003-0101.
This is for a '75 F337G.

Thanks

Pete

[Bob Cook]

Peter

The voltage regulator consists of two series pass transistors that are easily replaceable. The regulator is mounted up under the pilot's side centre console. The regulator can be removed for testing or repair.

Just check the transistors and replace. There is a relay that activates this regulator based on Autopilot power. There is a remote possiblity a wire is broken or the relay has either popped out of it's socket or is failing to energize.

Suggest remove and take to a repair facilty to check transistors if you are not experienced. It should be signed out in any event.

The transistors are mounted with two screws each.

hope this helps.

Bob

[Pete Somers]

Thanks Bob

I do know they are repairable and i have the circuit diagrams.

However somebody has removed the regulator and connected the trim power up to the 28 volts, so we are without a regulator to repair! (NOT GOOD)

This of course causes pitch problems in alt hold and when adjusting atittude that requires a trim change.

Just to let the forum know that i am an avionics engineer with a lot of experiance of all the Cessna range, including ARC radio's from the 1960's up to date this includes the 300/400/800/1000 autopilots. I have been working with the 336/337 since 1969 and have done various Cessna courses.

If i can provide any help let me know.

Many thanks
Pete

[Bob Cook]

Suggest you try autopilot central or just check around with various radio shops. The regulator is normally left in when upgrading autopilots.

Problem is the regulator is required to be functional with the electric trim regarless of having an autopilot.

Why would anyone remove the regulator is beyond me !!!!

Too bad you could just make one since it is a rather simple circuit.


Bob