Old 11-27-2013, 12:04 PM #1
The Lightning Stalker's Avatar
Class 3B Laser
 
Join Date: Aug 2013
Location: MI, US
Posts: 2,654
Rep Power: 387
The Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond repute
The Lightning Stalker The Lightning Stalker is offline
Class 3B Laser
The Lightning Stalker's Avatar
 
Join Date: Aug 2013
Location: MI, US
Posts: 2,654
Rep Power: 387
The Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond repute
Default Scientech Calorimeters and Negative Resistance

I am currently studying the manual for the 362 which was so kindly provided over on PL
hoping to build an LPM around my 038-0101 "calorimeter". The thing that got my attention
was the preamp section. I couldn't seem to figure out why there is a power darlington
stage after the op amp. About ready to give up, I started reading from the beginning,
(which I should've done in the first place) and there it was, a warning about not shorting the
leads because the 362 presents a negative resistance to the calorimeter. So I traced out
the preamp again and sure enough, it's a negative impedance converter.



So it is actually designed to force power back into the sensor. I'm thinking that these are
TEC sensors and the meter is cooling the sensor down again to get a faster response. It
may even be key to getting an accurate measurement.

I'm wondering if anyone else knows anything about this because none of the LPM preamp
circuits in the DIY meters perform this function.

As a side note, it seems that the art of manual writing is long lost. In this day and age of
online PDF manuals, there is a distinct lack of in-depth information, weather negligent or
intentional. Everyone is so greedy with their secret sauce and afraid to share any real
information. Instead of building with quality that makes people want to buy, it's like
everyone is trying to deplete imaginary competitors of the smallest tidbits of real
information. Anyway, that is just my impression. You each have your own, I'm sure.
Attached Thumbnails
Scientech Calorimeters and Negative Resistance-screenshot-2013-11-27-07-59-39.png  


__________________
ALL NEW MEMBERS MUST READ THIS!!! --> http://www.laserpointersafety.com

"Where, now, is the way by which the light distributes itself" - Job 38:24

YouTube Channel
The Lightning Stalker is offline   Reply With Quote








Old 11-27-2013, 09:03 PM #2
Hemlock_Mike's Avatar
Class 4 Laser
 
Join Date: Jan 2007
Location: North Iowa
Posts: 6,161
Rep Power: 1433
Hemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond repute
Hemlock_Mike Hemlock_Mike is online now
Class 4 Laser
Hemlock_Mike's Avatar
 
Join Date: Jan 2007
Location: North Iowa
Posts: 6,161
Rep Power: 1433
Hemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond repute
Default Re: Scientech Calorimeters and Negative Resistance

I had to get out my book -- I have 2 of these 362 meters.
The sensor is a TEC and the neg resistance may be to establish
a reference temp. I worked with a gas sensor once which used
the same principal to maintain a cathode temp based on heater
resistance.
HMike
__________________
Turn off that LASER Sherman!
Hemlock_Mike is online now   Reply With Quote
Old 09-21-2014, 12:28 AM #3
Class 2M Laser
 
Join Date: May 2009
Posts: 950
Rep Power: 537
LSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond repute
LSRFAQ LSRFAQ is offline
Class 2M Laser
 
Join Date: May 2009
Posts: 950
Rep Power: 537
LSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond repute
Default Re: Scientech Calorimeters and Negative Resistance

Google:

Self Balancing Bridge RF Power Meter.

Steve
LSRFAQ is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On











Loading








Top 50 Laser Pointer Companies - Green Lasers Top 50 Laser Pointer Companies - Blue Lasers Top 50 Laser Pointer Companies - Red Lasers
Top 50 Laser Pointer Companies - Yellow Lasers Top 50 Laser Pointer Companies - Purple Lasers Top 50 Laser Pointer Companies - Orange Lasers
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes




Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 11:10 AM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC