Panel warning lights

[kentb]

I have found a number of time 20 minutes into my flight that the fuel pump is still on. I have been think of putting in a light to remind me to turn if off after takeoff.
I can't hear the fuel pump running. I could add a item to my check list I guess.

Kent

[gorbak]

Tony,
You raise a very good question that can be addressed well by the RV community. There are hundreds of ways to properly address your question. Here is just one example. I am attaching a picture of my panel on the RV9-A with slider. The little light (nearly a black dot in the photo) directly above the 3 1/8" TruTrak ADI is a simple "low oil pressure" red light connected to the oil pressure sensor and is eye level.
The TruTrak auto pilot is well lit and very readable and has its own on/off button. I went one step further and wired this into a toggle switch so I could override the auto pilot and completely disconnect with a kill switch on the panel. I am confident that others have additional suggestions that I hope will work for you.
http://img329.imageshack.us/my.php?i...nelrv9axg1.jpg

Pat Garboden
Ozark, MO
RV9-A 942WG (reserved) slider with O-235 panel shown
RV9-A 942PT (reserved) tip-up with O-320

[f1rocket]

Originally Posted by kentb

I have found a number of time 20 minutes into my flight that the fuel pump is still on. I have been think of putting in a light to remind me to turn if off after takeoff.
I can't hear the fuel pump running. I could add a item to my check list I guess.

Kent

You must not go right to leaning the engine at cruise with an engine analyzer. Once I level off, I'm pulling the mixture back to run LOP. However, when I see the fuel flow on the EFIS, it's immediately apparent if the fuel pump is still on because the fuel flow will be about 28 GPH!!!! Better than any light.

Kent, you might just remember that the first time you reach to pull the throttle back, turn the fuel pump off. (or a light would work too!)

[f1rocket]

Originally Posted by gmcjetpilot

I agree 100%, yes Randy I agree.

George,

Take a couple of asprin and lay down. It will pass.

[rmcgann]

At the expense of starting an 'annunciator war', here is my view.

In my RV-10 I have the following warning annunciators:

1. stall
2. EIS warning
3. starter engaged
4. door ajar
5. CO detected

I also have the following indicating annunciators:
1. Fuel boost
2. landing light
3. taxi light
4. strobe
5. nav

I would not do without the warnings. I needed to have these 5 indicators. I wanted LEDs so I had to design the LED circuit anyway (dimming and a Press to test switch offer some challenges for LEDs).

As far as the 'indicators' I debated whether these were necessary, I had the same initial view of Stein and others that the switch indicated on/off state anyway. The reason I finally went with the indicators is simple - I have a fuse block, not circuit breakers for these systems. The indicator not only confirms whether the device is on or off, but also confirms that the fuse is in tact - not possible otherwise. During the day, can you see your nav lights, strobes or landing/taxi lights (I like my lights on in VFR transit lanes during the day), or know whether your boost fuse has failed? Addition of the indicators to the warning annunciator panel was trivial.

A bit more complexity sure, but with a LED reliability of >50000 hrs and minimal maintenance overhead, I don't see ANY disadvantages long term.

Each to his own, YMMV.

cheers,
Ron
-10 finishing

[gmcjetpilot]

There is always different ways to look at it.

It's funny because its true, guys are not as sophisticated.

PS here is a picture of my dog (after doing some aerobatics):


PSS Randy you where doing so well until you made the Aspirin comment, I'm a Ibuprofen man.

[JohnR]

That dog photo is funny! I like it. You know they say dogs and their owners usually look alike. Thanks for posting it, made for a good laugh.

[tonyjohnson]

Originally Posted by ClayR_9A

Make sure you have a dimmer for any light that will be "on" in normal operation.. like the fuel pump light. I found that the blue LED light that I used was WAY TOO BRIGHT at night.

I added a single switch on the ground side of my warning lights (they all ground through the switch). When the switch is on, current flows through as normal. (bright) When the switch is off, current flows through a resistor that jumps the switch. (dim) Just connect the resistor to each leg of the switch where the wires connect. You'll have to experiment to get the right resistor.

You can also use a pot instead of the switch for a variable dimmer.

Clay and Paul,

Thanks for the input regarding dimming of warning lights. I have installed 7 LED warning/indicator lights in my panel. I am using an LC-40 dimming unit and have a pot dedicated to the warning lights. I cannot figure out how to connect the warning lights to the dimmer. Each warning light will recieve its power from a separate source.

I note that Clay put the dimmer control on the ground side of the warning lights by using a switch. It would seem that using a pot, like the ones provided with the LC-40 could work as well, but I am unclear about how to hook that up.

The pot supplied with the LC-40 has three solder tabs. They all connect to the LC-40 unit normally. One for 5v power, one for ground, and the other to the "channel" in the unit for that pot. I am trying to figure out which of the tabs I would use to connect the pot inline on the ground side of the LED warning lights. I am thinking that the ground and "channel" tabs might be the two to use, and leave the power tab unused. Although it could be that I should use the ground tab and the power tab????

Can anyone help me understand how to to that.

Tony Johnson
Electrically challanged in Orlando

[vlittle]

Tony, you've hit on one of the most frustrating problems of annunciator lamps... how to dim them.

Some lamps are switched to +12, some to ground, and some to either (like flap motors).

Finally, the push-to-test function is complicated in this environment. You can see the lamp array below, along with the test pushbutton. They are for STALL, ENGINE (any engine alarm or low oil pressure sensor), FLAPS and BOOST pump indication.

Since I've modified my flap operation with a limit switch, I may change the FLAPS lamp to a PITOT lamp in the future.

I use the Vx Aviation IL-4A that I developed to solve this problem. It's also available in a 12-channel version. Both are distributed by Aircraft Extras .

Vern Litte -9A

[Ironflight]

Tony, for the case where you are dimming on the ground side of all the LED's Which is what I did), you are headed in the right direction using a simple pot between the LED's and ground - I would have no idea how to actually use the LC-40 that way. However, it can be a little bit of trial and error to figure out which pot you want to use. All depends on the LED's and what size resistors you use on each LED. You might want a 500 Ohm Pot, might need a 5K pot - fortunately, in my case, I have a surplus electronics parts place in the area, and I can by assorted pots for less than a buck - I get a few, and play around.

For the pot that you have, put an ohmmeter across the terminals in various combinations and vary the setting - you will quickly figure out which pins to use to get the varying resistance you want.

Paul