The International Cessna^® 170 Association

OK, so on my 1950 170A, the panel is lighted by 5 or 6 lights that are built into the bottom of the glare-shield. The lamps themselfs are small, about 1.3 inches long, and look a lot like circut breakers. they are 12 volt and 2 watt. the closest my wrench could find is one that is 1.375 long, 12 volts and 5 watt.

So, a few questions;

1) Are there replacments available?

if not:

2) Will the 5 watt bulbs suffice/

and

3) What, exactly, is the name of these lights? (So I don't sound quite as stupid next time).

Thanks
Rich

Sounds like you have an after market glare-shield, Can't recall the name of the product but I've heard it described here before.

If the 5 watt bulbs fit the you may have 2 other problems. First they will be brighter unless you have a dimmer. Second you will be doubling the amperage draw which may or may not be a problem depending on your dimmer and it's capacity and the actual wiring used to install it all.

Using Ohms law 2 watt bulbs at 12 volts would pull .16 amps. possibly times 6 depending on how the circuit is wired would be .96 amps total

5 watt bulbs at 12 volts will pull .42 amps per bulb and possibly 2.52 total amps depending again on how all 6 bulbs are wired.

Before I used the 5 watt bulbs I'd have someone knowledgeable in electronics review the installation to be sure the added amperage won't cause a problem and that it would be safe.

Hey, Rich... Why don't you look thru your aircraft records and attempt to locate where the modified lighting system/glare-shield was installed, and see if you can determine the manufacturer's contact info. (Also a good time to look for installation approval.)

Otherwise, you might go down to your local NAPA autoparts store and, taking one of your current (get it? ) bulbs with you, see if the Napa parts-guy will pull out his copy of the light/bulb catalog (Phillips/Sylvania) and find the match for it.
The catalogs will show the sizes, the base-types, the candle-power, and the wattage/voltage of virtually any light bulb. GE also puts out a catalog.

I only mention NAPA because I know most dealers carry those catalogs, but they are also available at many aviation supply houses such as Aviall, Spruce, Univair, etc.

Also check out:
http://www.lightbulbsdirect.com/lbe_miniature.html

and see their search page:

http://www.lightbulbsdirect.com/lbe_mini_inquiry.html#

Are those T-2 types like the "circuit breaker" look to which you were referring?

(It's possible to "click" on any group depicted and find their Max Overall Length "MOL" as well as their max diameter "MOD". YOu can also enter the voltage/wattage, etc. to search.

I would guess you've got the glare shield built by Robert Schroers. He sent me a package of replacement light bulbs two years ago when I asked him where to get them. What they actually are is still his secret, as far as I know, but it would be nice if someone could pry it out of him and document it for the Association.

According to Google, he's still at:

Robert J Schroers
(425) 746-9790
4479 139th Ave SE
Bellevue, WA 98006

Best Regards,

John

jrenwick wrote:I would guess...
...Best Regards,

John

John: Thank you very much for the info, yes, that is exactly what I have. I contacted Mr. Schroers, then ordered twelve of the lamps. I recieved them promptly and they are fine.

Thanks again
Rich