time-nuts@febo.com
Sent: Sun, Aug 26, 2012 12:31 pm
Subject: Re: [time-nuts] newbie question Thunderbolt supply
On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote:
Having played with several solutions I found the best is a 12 V 1 A
switcher with the output voltage increased to 15 V, check
Kehren
-Original Message-
From: Chris Albertson albertson.ch...@gmail.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Sun, Aug 26, 2012 12:31 pm
Subject: Re: [time-nuts] newbie question Thunderbolt supply
On Sun, Aug 26, 2012 at 3:46 AM
and frequency measurement
time-nuts@febo.com
Sent: Sun, Aug 26, 2012 12:31 pm
Subject: Re: [time-nuts] newbie question Thunderbolt supply
On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote:
Having played with several solutions I found the best is a 12 V 1 A
switcher
-nuts-boun...@febo.com] On
Behalf Of ewkeh...@aol.com
Sent: Monday, August 27, 2012 9:38 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] newbie question Thunderbolt supply
Thank you. Will look for it here under thermal pad.
Bert
In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time
On 08/27/2012 10:09 AM, Jerry wrote:
Are these thermal pads temp conductive or insulative? If you want heat
dissipation why not use the readily available thermal grease used for
semiconductor mounting? Cheap and not really messy if applied correctly
A layer of Kapton (polyimide) tape would be
...@gmail.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Sun, Aug 26, 2012 12:31 pm
Subject: Re: [time-nuts] newbie question Thunderbolt supply
On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote:
Having played with several solutions I found
:44 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] newbie question Thunderbolt supply
There are components and traces.
Bert
In a message dated 8/27/2012 10:10:45 A.M. Eastern Daylight Time,
jster...@att.net writes:
Are these thermal pads temp conductive or insulative? If you want heat
On Mon, Aug 27, 2012 at 3:48 AM, ew ewkeh...@aol.com wrote:
te and am looking for the material switchers use between semiconductor and
cooling plate Any one know where I can buy it in sheet form?
Bert Kehren
What happens if you flood the entire assembly in transformer oil? Aside
from
-boun...@febo.com] On
Behalf Of Chris Albertson
Sent: Monday, August 27, 2012 12:02 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] newbie question Thunderbolt supply
On Mon, Aug 27, 2012 at 3:48 AM, ew ewkeh...@aol.com wrote:
te and am looking
-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of ewkeh...@aol.com
Sent: Monday, August 27, 2012 10:44 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] newbie question Thunderbolt supply
There are components and traces.
Bert
In a message dated 8/27/2012 10:10:45 A.M. Eastern
of precise time and frequency measurement'
Subject: Re: [time-nuts] newbie question Thunderbolt supply
Are these thermal pads temp conductive or insulative? If you want heat
dissipation why not use the readily available thermal grease used for
semiconductor mounting? Cheap and not really messy
Having played with several solutions I found the best is a 12 V 1 A
switcher with the output voltage increased to 15 V, check the capacitors and if
necessary replace with 25 V. I laid out a PC board that has a TC7662A
inverter followed by a 79L12. Also on the board is a 7812 followed by a
Hi
The only real disadvantage of a 7812 / 340-12 is it's relatively high drop out
voltage compared to a 1764 (or similar). Stability of any of them will be
impacted more by thermal issues than anything else. The colder you can keep the
12V regulator, the more stable it will be. The +12 is by
On 08/26/2012 02:07 PM, Bob Camp wrote:
Hi
The only real disadvantage of a 7812 / 340-12 is it's relatively high drop out
voltage compared to a 1764 (or similar). Stability of any of them will be
impacted more by thermal issues than anything else. The colder you can keep the
12V regulator,
Having played with most combinations I could think of including the 1764
there is a lot to be said about the stability of the 7812 and mounting every
thing on one plate since power dissipation of the OCXO decreases with
increase in ambient temperature and current fluctuation is minimal since
On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote:
Having played with several solutions I found the best is a 12 V 1 A
switcher with the output voltage increased to 15 V, check the capacitors
and if
necessary replace with 25 V. I laid out a PC board that has a TC7662A
inverter
Hi all: I'm using buck regulators from our ebay friends, e.g. 130704328176
at a little over $1.00 apiece, settable to 5 v or 12 v or whatever,
capable of 3 A with good heatsink. Foldback protection. Better than a
3-legged fuse, as my good gaffer Argus calls 'em.
Don
Bob Camp
Hi
The only real
I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any
performance loss if the +12vdc rail and the -12vdc rail are off by a few %
in opposite directions, e,g +11.7 vdc and -12.3vdc ?
Tia
Jerry
___
time-nuts mailing list --
Hi
As long as the +12 is stable a few percent isn't going to hurt anything. The
-12 can be off by a few volts and everything will be fine.
Bob
On Aug 25, 2012, at 4:06 PM, Jerry jster...@att.net wrote:
I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any
performance loss
On Sat, Aug 25, 2012 at 1:06 PM, Jerry jster...@att.net wrote:
I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any
performance loss if the +12vdc rail and the -12vdc rail are off by a few %
in opposite directions, e,g +11.7 vdc and -12.3vdc ?
The true nuts here on the
Dear Chris,
Good afternoon. I am in the process of mounting my TBolt to a 2U 19 rack
enclosure and was looking for a decent power supply. I found the Cisco unit and
I am ordering a couple of them just in case. It would really be nice if I could
have access to the diagram of the upgrade you did
I never made a diagram. All I did was solder down a terminal block to
each end of a piece of prototype board. I connected the power lines using
some small inductors I had and bypassed power to ground using (I think)
0.01 caps.
I mounted the Cisco power supply block to the inside of the case
Hi
The easy way to do a TBolt supply is to start with something between 15 and 18
volts. Regulate down to 12 and 5 with linear regulators. 7805's are fine for
the +5. Something like a LT1764 might be better for the +12. The -12 supply is
very low current and does not matter much. People have
li...@rtty.us said:
The -12 supply is very low current and does not matter much.
Is the -12 used only for the RS-232, or is it also the negative supply to the
DAC? If the latter, the regulation and noise may be important.
I think I remember comments about it being used by the DAC. Wasn't
Hi
The -12 runs the RS-232 and the negative supply to the DAC buffer. As long as
it's past about -7V everything works pretty well. With no negative supply the
DAC may have issues. Most of the OCXOs run right around 0V….
Bob
On Aug 25, 2012, at 8:55 PM, Hal Murray hmur...@megapathdsl.net
I think I remember comments about it being used by the DAC. Wasn't there
some mention of the TBolt working with a dead -12 supply, but only as long as
the DAC output was above 0.
That was the conclusion. Actually the units these Thunderbolts were removed
from used -7VDC instead of -12VDC.
I would recommend a linear regulated supply rather than a 'switching'
supply.
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Arthur Dent
Sent: Saturday, August 25, 2012 9:25 PM
To: time-nuts@febo.com
Subject: [time-nuts] newbie
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