time and frequency measurement time-nuts@febo.com
Sent: Friday, February 3, 2012 4:55:20 AM
Subject: Re: [time-nuts] FE5680 missing PPS soln
On Fri, 3 Feb 2012 09:50:52 -
Rob Kimberley robkimber...@btinternet.com wrote:
Mine was a green LED out of the junk box, but I did use 330R
-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of bob grant
Sent: 02 February 2012 23:20
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FE5680 missing PPS soln
The LEDs are common garden variety, tied to +5V and inline with 1k8...I
On Fri, 3 Feb 2012 09:50:52 -
Rob Kimberley robkimber...@btinternet.com wrote:
Mine was a green LED out of the junk box, but I did use 330R in series. 1k8
seems rather large.
Then i'm not surprised that your FE-5680 refused to work :-)
Just calculate: 5V supply, approx 2V LED voltage - 3V
9mA
PaulG8GJA
-Original Message-
From: Attila Kinali [mailto:att...@kinali.ch]
Sent: 03 February 2012 12:55
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FE5680 missing PPS soln
On Fri, 3 Feb 2012 09:50:52 -
Rob Kimberley robkimber
Uhhh... last time I checked 3V/330 ohms is 9.1 milliamps, not 90 mA...
-
Just calculate: 5V supply, approx 2V LED voltage - 3V over the resistor.
3V/330R = 90mA
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Thank you Paul.
:-)
Rob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Reeves Paul
Sent: 03 February 2012 12:59
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] FE5680 missing PPS soln
9mA
Paul
On Fri, 3 Feb 2012 13:02:11 +
Mark Sims hol...@hotmail.com wrote:
Just calculate: 5V supply, approx 2V LED voltage - 3V over the resistor.
3V/330R = 90mA
Uhhh... last time I checked 3V/330 ohms is 9.1 milliamps, not 90 mA...
Uhh... last time i
Hi,
You need to check your maths...
:-)
Rob K
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Attila Kinali
Sent: 03 February 2012 12:55
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FE5680 missing
I'm using a 556 dual timer, one section as an inverter to drive a lock
led, and the other section as a pulse stretcher to drive a 1 pps led.
Let's get on with it.
Don
Attila Kinali
On Fri, 3 Feb 2012 09:50:52 -
Rob Kimberley robkimber...@btinternet.com wrote:
Mine was a green LED out of
Some info...
Its tempting to attach an LED to the /LOCK signal on the DB9.
However this signal is very weak and the LED does not seem very bright
and PPS signal does not pulse...Hmm
Internally the /LOCK pin is connected the 74AC240 buffer, but with an
LED helping to keep the signal voltage high
To: time-nuts@febo.com
Subject: [time-nuts] FE5680 missing PPS soln
Some info...
Its tempting to attach an LED to the /LOCK signal on the DB9.
However this signal is very weak and the LED does not seem very bright
and PPS signal does not pulse...Hmm
Internally the /LOCK pin is connected the 74AC240
...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of bob grant
Sent: 02 February 2012 20:46
To: time-nuts@febo.com
Subject: [time-nuts] FE5680 missing PPS soln
Some info...
Its tempting to attach an LED to the /LOCK signal on the DB9.
However this signal is very weak and the LED does
YMMV but, if there's any chance of a PPS output it'll be arriving at pin
2 of the 74AC240 buffer.
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On Thu, 02 Feb 2012 12:46:01 -0800
bob grant bobgr...@fastmail.fm wrote:
Some info...
Its tempting to attach an LED to the /LOCK signal on the DB9.
However this signal is very weak and the LED does not seem very bright
and PPS signal does not pulse...Hmm
Internally the /LOCK pin is
The LEDs are common garden variety, tied to +5V and inline with 1k8...I
was expecting 2ma or so.
Note, whereas the PPS signal is buffered the LOCK signal for the DB9 is
not passed though the 74ACT240 buffer.
On Thu, Feb 2, 2012, at 11:10 PM, Attila Kinali wrote:
On Thu, 02 Feb 2012 12:46:01
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