Matronics Email Lists :: View topic - Tach / regulator problem

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Tach / regulator problem

Matronics Email Lists Forum Index -> Kolb-List

View previous topic :: View next topic

Author Message

Dana

Joined: 13 Dec 2007
Posts: 1047
Location: Connecticut, USA

Posted: Mon Jun 28, 2010 9:04 am Post subject: Tach / regulator problem

I'm having a bit of an electrical problem on my UltraStar. 



 The plane has a Westach tach/EGT combo; the tach runs directly off the lighting coil on the Cuyuna and always worked fine. I just added a Key West regulator so I can have 12VDC power for my strobe and radio. The tach and regulator are wired in parallel to the lighting coil (unlike the Rotax, the Cuyuna has a single lighting coil). No battery. However, with the regulator connected, the tach reads low.



 Here's the weird part. When I first installed the regulator, the read low, no more than about 2500 rpm indicated at full throttle (6500 rpm). However, when I switched on the strobe, it read correctly, except for a momentary blip as the strobe fired. Figuring I needed a load on the regulator, I added a 50 ohm resistor to the output to draw a constant 1/4 amp. Now it indicates about 5000 rpm when the engine is actually doing 6500, regardless of whether the strobe is on or off. I then disconnected the resistor, which made no difference (still reads 5000). Finally, I disconnected the regulator, and the tach again reads correctly.



 I went up to the airfield yesterday with some other components and test leads, etc… figured on trying a capacitor across the output instead of the resistor, or a smaller resistor on the input between the tach and regulator, but it was too hot to fiddle with t… much nicer to go up a couple thousand feet and cool off.



 Has anybody else seen this problem? 



 -Dana 

 

 --

  If aliens are smart enough to travel through space, why do they keep abducting the dumbest people on earth?    [quote][b]

- The Matronics Kolb-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List

Richard Pike

Joined: 09 Jan 2006
Posts: 1671
Location: Blountville, Tennessee

Posted: Mon Jun 28, 2010 10:45 am Post subject: Re: Tach / regulator problem

I had a similar situation several years ago when I went through months of weirdness with my tach and my Key West regulator. Ended up buying a Tiny Tach and have had no more problems. You wrap a sensing wire around the spark plug lead and it counts the actual pulses. Simple, reliable and a digital readout.



Richard Pike

MKIII N420P (420ldPoops)

- The Matronics Kolb-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List

Dana

Joined: 13 Dec 2007
Posts: 1047
Location: Connecticut, USA

Posted: Mon Jun 28, 2010 1:40 pm Post subject: Tach / regulator problem

At 02:45 PM 6/28/2010, Richard Pike wrote:

 [quote]--> Kolb-List message posted by: "Richard Pike" <richard(at)bcchapel.org>



 I had a similar situation several years ago when I went through months of weirdness with my tach and my Key West regulator. Ended up buying a Tiny Tach and have had no more problems. You wrap a sensing wire around the spark plug lead and it counts the actual pulses. Simple, reliable and a digital readout.



 Richard Pike

 MKIII N420P (420ldPoops)



 



 

 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=302863#302863



 



 



 



 Email Forum -

 http://www.matronics.com/Navigator?Kolb-List

 - MATRONICS WEB FORUMS -

 http://forums.matronics.com

 - List Contribution Web Site -

 -Matt Dralle, List Admin.

 http://www.matronics.com/contribution

 --

  Why doesn't the fattest man in the world become a hockey goalie?    [quote][b]

- The Matronics Kolb-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List

Display posts from previous:

	Matronics Email Lists Forum Index -> Kolb-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum