Installing a landing light blinker in an Archer

A while back I asked for information about installing a landing light
blinker system in an Archer. Now that the job is done I'll share my
experiences with the Great Planetary Bit-Bucket.
First off, I'm very pleased with the system. I want Jim Weir to know his
generosity was not in vain! Thanks again, Jim.
Jim supplied the 2 field effect transistors with electrically insulated heat
sinks and the two surge current limiting thermistors along with a schematic.
The rest of the stuff came from Radio Shack and another local electronics
store.
The particular question in the Archer was how to hook up the pulsed output
across the landing-light switch. Since the LL rocker is essentially
inaccessible to everyone except the original assembly workers at Piper, I
ran a 16 gauge wire through the firewall to the LL connector in front of the
firewall and replace the two wire connector with a three (actually four)
wire connector to splice in the 12 volt pulsed output.
The other head-scratcher was were to place the thermistor since Jim
suggested it would be better to get it out of the cockpit. It ended up on a
small piece of circuit board screwed to one side of the LL. It essentially
became part of the wire that gets taken on and off when the bulb needs
changing.
The one slight mod I did to Jim's schematic was to add 500 ohm resistors in
series with yellow LED's on each pulsed output so the blink rate is visible
in the cockpit. A side benefit of the LED's is that when the LL switch is
on, the LL LED is also on, even when the pulse system is turned off. If the
pulse system is also on, the LED stays on without blinking.
--
Best Regards,
Mike.

http://flickr.com/photos/mikenoel/

..
If you added 500 ohm resistors to the circuit you've done something no other
human being has done since RETMA took charge of component values prior to
WWII. 470 or 510 maybe?

Jim



The one slight mod I did to Jim's schematic was to add 500 ohm resistors

RST Engineering wrote:
.
If you added 500 ohm resistors to the circuit you've done something no other
human being has done since RETMA took charge of component values prior to
WWII. 470 or 510 maybe?

Jim



The one slight mod I did to Jim's schematic was to add 500 ohm resistors



500 is not an uncommon value for power resistors.
Huntington Electric lists it as a standard value:
http://www.heiresistors.com/axialresistor.htm

Curt

Jim, I had actually calculated 540 ohms for 13 volts and went looking for
560 ohms resistors. My local RS didn't have any 560's so I settled for two
1K 1/4 Watts in parallel. Good catch.

--
Best Regards,
Mike.

http://flickr.com/photos/mikenoel/
"RST Engineering" wrote in message
m...
.
If you added 500 ohm resistors to the circuit you've done something no
other human being has done since RETMA took charge of component values
prior to WWII. 470 or 510 maybe?

Jim



The one slight mod I did to Jim's schematic was to add 500 ohm resistors

I'd be interested in the Form 337 for the install.
Or is there a standard STC? Sounds like a homemade solution in a Standard
certificated aircraft.
B

"Mike Noel" wrote in message
...
Jim, I had actually calculated 540 ohms for 13 volts and went looking for
560 ohms resistors. My local RS didn't have any 560's so I settled for
two
1K 1/4 Watts in parallel. Good catch.

--
Best Regards,
Mike.

http://flickr.com/photos/mikenoel/
"RST Engineering" wrote in message
m...
.
If you added 500 ohm resistors to the circuit you've done something no
other human being has done since RETMA took charge of component values
prior to WWII. 470 or 510 maybe?

Jim



The one slight mod I did to Jim's schematic was to add 500 ohm
resistors

Minor modifications as delineated in FAR part 43 can be accomplished with a
logbook entry by an airframe mechanic. Parts for a person's own aircraft
may be personally fabricated in accordance with 21.303(b)(2).

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


"BT" wrote in message
...
I'd be interested in the Form 337 for the install.
Or is there a standard STC? Sounds like a homemade solution in a Standard
certificated aircraft.

The OP was talking about a current limiting resistor for an LED panel light.
A quarter watt resistor is overkill. Understand what is being discussed.
Google RETMA values if you must.

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle



500 is not an uncommon value for power resistors.
Huntington Electric lists it as a standard value:
http://www.heiresistors.com/axialresistor.htm

Curt

Uh, I only stated that it was possible, not that it was the most
efficient solution. It was said that parts were obtained from local
sources. My local electronics surplus shop has stranger things.

Curt


RST Engineering wrote:
The OP was talking about a current limiting resistor for an LED panel light.
A quarter watt resistor is overkill. Understand what is being discussed.
Google RETMA values if you must.

Jim

"RST Engineering" wrote in message
m...
Minor modifications as delineated in FAR part 43 can be accomplished with
a logbook entry by an airframe mechanic. Parts for a person's own
aircraft may be personally fabricated in accordance with 21.303(b)(2).

Jim

--

Isn't there also a specific exemption for a landing light circuit?

Thanx Jim..
B

"RST Engineering" wrote in message
m...
Minor modifications as delineated in FAR part 43 can be accomplished with
a logbook entry by an airframe mechanic. Parts for a person's own
aircraft may be personally fabricated in accordance with 21.303(b)(2).

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


"BT" wrote in message
...
I'd be interested in the Form 337 for the install.
Or is there a standard STC? Sounds like a homemade solution in a Standard
certificated aircraft.