S
Simoc
Sorry for reposting, so I posted earlier a thread "Problems with
building an ESR meter",
http://groups.google.fi/group/sci.e...ead/a2a2bc5b2520bed9/909e2ffec4e9986f?lnk=arm
(Question is about a home-made ESR meter, documentation here:
http://www.ludens.cl/Electron/esr/esr.html )
Well, now I measured those and got:
Output: 2.65 V
- Input: 2.65 V
+ Input: 2.48 V
Vcc: 4.95 V
So it seems to be oscillating, although I'm a little confused about
that all of them are a little above 1/2 Vcc...but might that just be an
error of DMM in measuring average of pulsating DC?
On DC range, DMM read just 0 mV...but is it AC or DC across the R6?
On AC range, the DMM read 8 mV. Across the R5 I got the same readings.
And btw, if it's AC voltage across the R6, does the DMM give any
reasonable readings, as it's high frequncy square wave? (as AFAIK
usually
the AC range of DMM's is optimized for 50/60Hz sine wave)
How could I continue troubleshooting now?
Thanks in advance.
Simoc
building an ESR meter",
http://groups.google.fi/group/sci.e...ead/a2a2bc5b2520bed9/909e2ffec4e9986f?lnk=arm
(Question is about a home-made ESR meter, documentation here:
http://www.ludens.cl/Electron/esr/esr.html )
If the oscillator is running you should have an average voltage of
about 1/2 Vcc on the plus input, the minus input, and the output.
Well, now I measured those and got:
Output: 2.65 V
- Input: 2.65 V
+ Input: 2.48 V
Vcc: 4.95 V
So it seems to be oscillating, although I'm a little confused about
that all of them are a little above 1/2 Vcc...but might that just be an
error of DMM in measuring average of pulsating DC?
If the oscillator and transformer are ok, and you
short the test leads, you should get (per the article) around 200 mV
across R6.
On DC range, DMM read just 0 mV...but is it AC or DC across the R6?
On AC range, the DMM read 8 mV. Across the R5 I got the same readings.
And btw, if it's AC voltage across the R6, does the DMM give any
reasonable readings, as it's high frequncy square wave? (as AFAIK
usually
the AC range of DMM's is optimized for 50/60Hz sine wave)
How could I continue troubleshooting now?
Thanks in advance.
Simoc