Inverter question for Jim Weir

clare, @, snyder.on, .ca wrote:

On Wed, 11 Feb 2004 12:28:32 -0800, Jim Weir wrote:

I love it when people without a clue jump on your questions that you asked me.

It can be done. I'm not sure how trivial the mod would be, but if you are
talking about powering 115v/400Hz. gyros, as I recall you will need three phase.

So the answer to question one is yes, I can probably figure out a way. I'm not
sure how detailed the answer will be, or whether the answer will travel from one
model to another or be specific to that model.

Now, what is an LCD inverter?

Jim


(B2431)
shared these priceless pearls of wisdom:

-Could you figure a way to convert the automobile inverters for laptops to
400z?
-How about the LCD inverters?
-
-Dan, U.S. Air Force, retired

Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

I think by LCD inverter he's talking about the "exciter" for the CCF
backlights used on LCD laptop screens. Aprox 400cps, but far from
accurate, and very low current.

However, I think the auto inverters for laptops are probably the 150-to 600+
watt 12 DC to 120 AC inverters that plug into the cig lighter socket & let you use
a laptop, shaver, whatever uses house current.
I made a HIGH POWERED strobe light that took about 450-500 vdc to pump
up the flash caps--Thought about winding toroid for transistor oscillator power
supply----But, then I let the Chinks do it--just used a 250 watt inverter and a
simple
voltage tripler circuit to power it... Jerry

From: "Tim Ward"
Date: 2/11/2004 9:58 PM Central Standard Time
Message-id:


"Tarver Engineering" wrote in message
...

"richard riley" wrote in message
...
On Wed, 11 Feb 2004 12:28:32 -0800, Jim Weir wrote:

:I love it when people without a clue jump on your questions that you
asked me.
:
:It can be done. I'm not sure how trivial the mod would be, but if you
are
:talking about powering 115v/400Hz. gyros, as I recall you will need
three
phase.

Most of the 115v/400 hz gyros out there are 3 phase, but not all. I
have one that isn't - it's not working and it's not worth rebuilding.
I'd guess 90% or more are three phase.

Most airplane instrumentation is devided by phase, gyros being one of the
most critical pieces of instrumentation for IFR operations.

Mechanical INS are three phase, but they have battery back up.

Cool! Where do they get those 3-phase batteries?

Tim Ward


Beat me to it, ya bum.

Dan, U.S. Air Force, retired

Jim Weir
From: Jim Weir


I love it when people without a clue jump on your questions that you asked
me.

It can be done. I'm not sure how trivial the mod would be, but if you are
talking about powering 115v/400Hz. gyros, as I recall you will need three
phase.

Someone gave me a neat trick using a cpacitor off one leg to trick the
instrument into thinking it's the third phase.

So the answer to question one is yes, I can probably figure out a way. I'm
not sure how detailed the answer will be, or whether the answer will travel
from
one model to another or be specific to that model.

This is an example of the type of inverter I have in mind:
http://cgi.aol.ebay.com/ws/eBayISAPI...45456&category
=42167

Now, what is an LCD inverter?

Example:
http://cgi.aol.ebay.com/ws/eBayISAPI...38717&category
=42187


Jim


Dan, U.S. Air Force, retired

On Wed, 11 Feb 2004 19:58:40 -0800, "Tim Ward"
wrote:



Mechanical INS are three phase, but they have battery back up.

Cool! Where do they get those 3-phase batteries?

Tim Ward

Same place they get the AC batteries, I suspect.

clare @ snyder.on .ca wrote in message
...
On Wed, 11 Feb 2004 19:58:40 -0800, "Tim Ward"
wrote:

Mechanical INS are three phase, but they have battery back up.

Cool! Where do they get those 3-phase batteries?

Same place they get the AC batteries, I suspect.

It has more to do with the DC accelerometers and designing for reliability.

Back when 707s ruled the world there were mag amps for operational
amplifiers and mica capacitors were what could survive comertial operations
and storage. A three phase DC source with a battery is how clean DC power
could be made reliably.

Silly, they just use 3 little batteries instead of 1 big one.

"Tarver Engineering" wrote in message
...

clare @ snyder.on .ca wrote in message
...
On Wed, 11 Feb 2004 19:58:40 -0800, "Tim Ward"
wrote:

Mechanical INS are three phase, but they have battery back up.

Cool! Where do they get those 3-phase batteries?

Same place they get the AC batteries, I suspect.

It has more to do with the DC accelerometers and designing for
reliability.

Back when 707s ruled the world there were mag amps for operational
amplifiers and mica capacitors were what could survive comertial
operations
and storage. A three phase DC source with a battery is how clean DC power
could be made reliably.

I know I'm going to hate myself for asking, but what is "three phase DC"?
How do you determine the phase angle of DC?

Tim Ward

"Tim Ward" wrote in message
...

"Tarver Engineering" wrote in message
...

clare @ snyder.on .ca wrote in message
...
On Wed, 11 Feb 2004 19:58:40 -0800, "Tim Ward"
wrote:

Mechanical INS are three phase, but they have battery back up.

Cool! Where do they get those 3-phase batteries?

Same place they get the AC batteries, I suspect.

It has more to do with the DC accelerometers and designing for
reliability.

Back when 707s ruled the world there were mag amps for operational
amplifiers and mica capacitors were what could survive comertial
operations
and storage. A three phase DC source with a battery is how clean DC
power
could be made reliably.

I know I'm going to hate myself for asking, but what is "three phase DC"?
How do you determine the phase angle of DC?

Three phase is easy to convert to DC.

From: "Tarver Engineering"


"Tim Ward" wrote in message


"Tarver Engineering" wrote in message
...

clare @ snyder.on .ca wrote in message
...
On Wed, 11 Feb 2004 19:58:40 -0800, "Tim Ward"
wrote:

Mechanical INS are three phase, but they have battery back up.

Cool! Where do they get those 3-phase batteries?

Same place they get the AC batteries, I suspect.

It has more to do with the DC accelerometers and designing for
reliability.

Back when 707s ruled the world there were mag amps for operational
amplifiers and mica capacitors were what could survive comertial
operations
and storage. A three phase DC source with a battery is how clean DC
power
could be made reliably.

I know I'm going to hate myself for asking, but what is "three phase DC"?
How do you determine the phase angle of DC?

Three phase is easy to convert to DC.


Tim, you should know better than to ask. As you can see he twists his answer so
he won't have to admit he made a mistake when he said "a three phase DC
source."

Dan, U.S. Air Force, retired

"B2431" wrote in message
...
From: "Tarver Engineering"


"Tim Ward" wrote in message


"Tarver Engineering" wrote in message
...

clare @ snyder.on .ca wrote in message
...
On Wed, 11 Feb 2004 19:58:40 -0800, "Tim Ward"

wrote:

Mechanical INS are three phase, but they have battery back up.

Cool! Where do they get those 3-phase batteries?

Same place they get the AC batteries, I suspect.

It has more to do with the DC accelerometers and designing for
reliability.

Back when 707s ruled the world there were mag amps for operational
amplifiers and mica capacitors were what could survive comertial
operations
and storage. A three phase DC source with a battery is how clean DC
power
could be made reliably.

I know I'm going to hate myself for asking, but what is "three phase
DC"?
How do you determine the phase angle of DC?

Three phase is easy to convert to DC.


Tim, you should know better than to ask. As you can see he twists his
answer so
he won't have to admit he made a mistake when he said "a three phase DC
source."