trick to detecting clock?
 

Is there some way to detect a 3-5volt say khz clock using an ordinary
instrument(no osciloscope)

trick to detecting clock?
 

wrote in message
...
Is there some way to detect a 3-5volt say khz clock using an ordinary
instrument(no osciloscope)

A crystal earpiece, assuming voltages not more than 50 volt.
A much underestimated piece of diagnostic test gear.


--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

trick to detecting clock?
 

On Sat, 14 Jun 2008 03:15:26 -0700 (PDT), "
wrote:

Is there some way to detect a 3-5volt say khz clock using an ordinary
instrument(no osciloscope)

---
AC or DC voltmeter.

JF

trick to detecting clock?
 

wrote in message
...
Is there some way to detect a 3-5volt say khz clock using an ordinary
instrument(no osciloscope)


With a multimeter that measures frequency.



Gareth.

trick to detecting clock?
 

On Sat, 14 Jun 2008 03:15:26 -0700 (PDT), "
wrote:

Is there some way to detect a 3-5volt say khz clock using an ordinary
instrument(no osciloscope)

You can use your computer's sound card. You can add a voltage
divider to insure the sound card Line input is getting less than about
3 Vpp, if you want to make sure you don't clip its input. (The input
can handle 5V without damage, but the wave will be clipped.) If you
want to avoid loading the clock output with the sound card input
(which can be in the 2K to 47K range), you can use big resistors for
the divider. Don't worry about dividing it down too low... the sound
card has 16 bits of resolution, so you'll be able to see
sub-millivolts easily.

SHAMELESS PLUG: You can try my Daqarta software for free.
It has calibration options so you can use it as a real scope (as well
as spectrum analyzer, frequency counter, voltmeter, sound level meter,
signal generator, etc, etc). If you decide not to buy (US$29.00)
after the trial expires, the inputs stop working but the signal
generator keeps working FREE forever, along with file analysis, etc.

I'll be glad to answer any questions.

Best regards,


Bob Masta

DAQARTA v4.00
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
FREE Signal Generator
Science with your sound card!

trick to detecting clock?
 

" wrote in news:ce59ac53-6740-
:

Is there some way to detect a 3-5volt say khz clock using an ordinary
instrument(no osciloscope)

With a few ICs and LEDs you can build a logic probe with pulse detection.

http://www.eng.cam.ac.uk/DesignOffic...per/EXP_7.html
has several interesting circuits, easy to build.

and for a 'delux' device
http://members.cox.net/berniekm/super.html





--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

trick to detecting clock?
 

Might I point out that an oscilloscope _is_ an "ordinary instrument"? At
least, in my sense of the word "ordinary" -- it's ordinarily found in any
electronics shop.

I work at Microsoft Hardware, and there has been a total switchover to
multi-color LCD 'scopes. The cheaper ones are not _horribly_ expensive.

trick to detecting clock?
 

The obvious choice, as Mr Cook says, is a crystal earpiece.

With one of those, the OP won't even need to make 2 connections;
just touching the tip of the jack plug on the conductor that's
oscillating at a few kHz and a few volts will be enough to make
it faintly audible with careful listening.


Martin

trick to detecting clock?
 

Fleetie wrote:
The obvious choice, as Mr Cook says, is a crystal earpiece.

With one of those, the OP won't even need to make 2 connections;
just touching the tip of the jack plug on the conductor that's
oscillating at a few kHz and a few volts will be enough to make
it faintly audible with careful listening.


One of the most useful bit of kit in my toolbox is a device I made
myself some 35 or so years ago. It`s a crystal earpiece with one wire
terminated in a croc clip and the other in a probe made from an old
ballpoint pen and a brass nail, there`s a capacitor in series to provide
DC blocking.
With this simple device I can trace audio through a circuit- from the
output of a crystal pick-up to several hundreds watts, I can detect
digital pulses, hear hum on a DC supply, etc. etc.

Ron(UK)

trick to detecting clock?
 

trick to detecting clock?
 

"N_Cook" wrote in message
...
wrote in message
...
Is there some way to detect a 3-5volt say khz clock using an ordinary
instrument(no osciloscope)

A crystal earpiece, assuming voltages not more than 50 volt.
A much underestimated piece of diagnostic test gear.


--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England


What a fascinating collection of notes you've kept on repairs you've carried
out and published on your web site!

Thank you for that,

Chris

trick to detecting clock?
 

trick to detecting clock?
 

On Sat, 14 Jun 2008 07:02:27 -0700, "William Sommerwerck"
put finger to keyboard and composed:

I work at Microsoft Hardware ...

That's handy to know. I have a wireless MS keyboard which I believe
has a design bug in its firmware. I wonder how one would go about
reporting something like that, or at least talking to a real human
being who understands the problem.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

trick to detecting clock?
 

Let me know what the problem appears to be, and I will pass it along to the
designers.

"Franc Zabkar" wrote in message
...
On Sat, 14 Jun 2008 07:02:27 -0700, "William Sommerwerck"
put finger to keyboard and composed:

I work at Microsoft Hardware ...

That's handy to know. I have a wireless MS keyboard which I believe
has a design bug in its firmware. I wonder how one would go about
reporting something like that, or at least talking to a real human
being who understands the problem.

trick to detecting clock?
 

On Sat, 14 Jun 2008 03:15:26 -0700 (PDT), "
put finger to keyboard and composed:

Is there some way to detect a 3-5volt say khz clock using an ordinary
instrument(no osciloscope)

If you are asking this question because you need to detect whether the
clock is oscillating, rather than trying to measure its frequency,
then find a buffered logic gate where the clock should be present and
measure the voltage there. If the clock is oscillating, then you
should measure a DC voltage equivalent to half the supply rail.
Depending on the frequency response of your multimeter, the voltage on
the AC range may be 0, so that won't be a good guide. If the clock is
dead, then the gate will be sitting on 0V or close to the positive
supply rail. Of course I'm assuming that the clock is a 50:50 square
wave. BTW, you probably won't get any sensible result measuring the
voltage at, or near, the crystal.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

trick to detecting clock?
 

On Sat, 14 Jun 2008 17:23:31 -0700, "William Sommerwerck"
put finger to keyboard and composed:

Let me know what the problem appears to be, and I will pass it along to the
designers.

The problem is explained in this thread:
http://groups.google.com/group/micro...6?dmode=source

It shows up when I use this old DOS utility to report the scan code of
each key:
http://www.users.on.net/~fzabkar/SCAN.COM

More background info he
http://groups.google.com/group/micro...d?dmode=source

Another related (?) problem is the spurious undocumented "E0 59" scan
code pair:
http://www.users.on.net/~fzabkar/MSKeyLog.TXT

The above problem shows up in Microsoft's mskey.exe diagnostic test.

"Franc Zabkar" wrote in message
.. .
On Sat, 14 Jun 2008 07:02:27 -0700, "William Sommerwerck"
put finger to keyboard and composed:

I work at Microsoft Hardware ...

That's handy to know. I have a wireless MS keyboard which I believe
has a design bug in its firmware. I wonder how one would go about
reporting something like that, or at least talking to a real human
being who understands the problem.


- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

trick to detecting clock?
 

Ron(UK) wrote in message
...
Fleetie wrote:
The obvious choice, as Mr Cook says, is a crystal earpiece.

With one of those, the OP won't even need to make 2 connections;
just touching the tip of the jack plug on the conductor that's
oscillating at a few kHz and a few volts will be enough to make
it faintly audible with careful listening.


One of the most useful bit of kit in my toolbox is a device I made
myself some 35 or so years ago. It`s a crystal earpiece with one wire
terminated in a croc clip and the other in a probe made from an old
ballpoint pen and a brass nail, there`s a capacitor in series to provide
DC blocking.
With this simple device I can trace audio through a circuit- from the
output of a crystal pick-up to several hundreds watts, I can detect
digital pulses, hear hum on a DC supply, etc. etc.

Ron(UK)

I must do the same sometime.
I've always picked up the standard earpiece and a pair of croc-leads and a
needle point rather than making a purpose built tool. Adding in a HV cap if
monitoring for noisy HT lines.
A scope would not show any more info in that situation and avoids
possibility of connecting scope up, in DC mode, set on 1mV/cm or HT pulse
transmitted through internal cap of scope, on a low range, and out goes dual
gate FET or whatever.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

trick to detecting clock?
 

On Mon, 16 Jun 2008 15:06:50 +0100, "N_Cook"
wrote:

must do the same sometime.
I've always picked up the standard earpiece and a pair of croc-leads and a
needle point rather than making a purpose built tool. Adding in a HV cap if
monitoring for noisy HT lines.
A scope would not show any more info in that situation and avoids
possibility of connecting scope up, in DC mode, set on 1mV/cm or HT pulse
transmitted through internal cap of scope, on a low range, and out goes dual
gate FET or whatever.

At home I have an old analog scope with "Y" output, onto which I
connected a simple amp+speaker.

The ticks / hums / squieks out of the speaker are extremely revealing
about what is measured; most of the time I do not need to look at the
screen at all.

In a cpu setup, one can even hear the software "run" on an adress
line (reoccurring sound patterns), and actually hear subroutines and
such.

At the office, the sophisticated DSO's no longer have this very useful
option..

--
- René

trick to detecting clock?
 

Blarp wrote:

snip
At home I have an old analog scope with "Y" output, onto which I
connected a simple amp+speaker.

The ticks / hums / squieks out of the speaker are extremely revealing
about what is measured; most of the time I do not need to look at the
screen at all.

In a cpu setup, one can even hear the software "run" on an adress
line (reoccurring sound patterns), and actually hear subroutines and
such.

Audio monitoring of program execution was standard practice on large
computers for decades and for me is a sadly missed diagnostic of an
often more useful nature than flow graphs and trace dumps. Using
an AM or FM radio near programmed logic can sometimes provide similar
functionality.

Michael

trick to detecting clock?
 

On Wed, 18 Jun 2008 10:30:38 -0500, msg wrote:

Audio monitoring of program execution was standard practice on large
computers for decades and for me is a sadly missed diagnostic of an
often more useful nature than flow graphs and trace dumps. Using
an AM or FM radio near programmed logic can sometimes provide similar
functionality.

Then there was the demo program supplied (on cassette tape, natch) by
The Digital Group for their Z80 systems, which "played" the Star
Spangled Banner all over the AM band to a nearby radio while
ASCII-arting a flag-like object on its 16x64 display. Way cool ...

--
Rich Webb Norfolk, VA