Search found 87 matches

by Craig
Thu Mar 15, 2007 12:32 pm
Forum: General Discussion
Topic: Question about resistor tolerances
Replies: 31
Views: 6550

Ok, if I understand you correctly, it should be like this: http://www.comeseethis.com/media/schem2.jpg Is that correct? This is the beauty of split supplies.(You are using the split supply as shown,aren't you) Umm, I don't know what you mean. Well, maybe I do know. When you say "split supply", do yo...
by Craig
Thu Mar 15, 2007 9:09 am
Forum: General Discussion
Topic: Question about resistor tolerances
Replies: 31
Views: 6550

The exact model number is LTKA00CN8 made by Linear Technology ( http://www.linear.com ). I have look for a datasheet for this part, but I don't think one exists. The only thing I could find is a datasheet for the LTKA00CN8 Op-Amp and the LT1025CN8 Cold Junction Compensator as a combined IC, part num...
by Craig
Thu Mar 15, 2007 7:01 am
Forum: General Discussion
Topic: Question about resistor tolerances
Replies: 31
Views: 6550

are you sure you can run the V- of the op amp to ground instead of a negative supply voltage? Try a battery if not just to see if it helps. No, I'm not sure. Isn't "ground" and "a negative supply voltage" the same thing, or do they need to be different voltage sources? If I hook up V- to a battery,...
by Craig
Thu Mar 15, 2007 5:49 am
Forum: General Discussion
Topic: Question about resistor tolerances
Replies: 31
Views: 6550

Thanks for the info guys! Although I was able to read the schematic, I didn't truly understand, your explanations really helped! I think I will tkae up Dave's offer on those 1% resistors! I built the circuit last night, but when I tested it I was receiving an output voltage of 0.554V regardless of t...
by Craig
Wed Mar 14, 2007 2:17 pm
Forum: General Discussion
Topic: Question about resistor tolerances
Replies: 31
Views: 6550

Thanks Dave, that would be awesome! (Did you know I live in Canada?)

Anyways, I will see what I can do with the 5% ones and check how accurate they are. I'll PM you if I end up needing them.
by Craig
Wed Mar 14, 2007 1:33 pm
Forum: General Discussion
Topic: Question about resistor tolerances
Replies: 31
Views: 6550

The electronics will be at or clse to room temperature, in a box seperate from the item being measured.

Image
by Craig
Wed Mar 14, 2007 1:11 pm
Forum: General Discussion
Topic: Question about resistor tolerances
Replies: 31
Views: 6550

Thanks for the replies! The applicaiton is for an op-amp for a cold junction compensator for a J type thermocouple. More specifically, it is for Linear Technology cold junction compensater part number LT1025CN8 and Linear Technology op-amp part number LTKA00CN8. Linear Tech also has a chip that has ...
by Craig
Wed Mar 14, 2007 11:06 am
Forum: General Discussion
Topic: Question about resistor tolerances
Replies: 31
Views: 6550

Question about resistor tolerances

I want to build a circuit that calls for a 1M 1/4W 1% resistor. I couldn't find any at my local electronics store so I bought a pack of 5% instead. Would it be ok to test them until I find one that is within 1% of 1M and use it? Does this tolerance come into affect while the circuit is in use (tempe...
by Craig
Thu Mar 08, 2007 9:55 am
Forum: General Discussion
Topic: Question about power supplies
Replies: 6
Views: 2217

Question about power supplies

since we're on the topic of power supplies, have any of you used a computer (AT or ATX) power supply as your bench power supply? I have been using an old AT power supply I pulled from my old Pentium 166 computer. It has 12v and 5v leads. I recently measured the 5v output and it's at 5.26 volts. Sinc...
by Craig
Wed Mar 07, 2007 12:13 pm
Forum: General Discussion
Topic: Question about Capacitors
Replies: 5
Views: 1400

Thanks for the info guys!

As far as the transformers go, I have found a place called Hammond Manufacturing (http://www.hammondmfg.com) that has a 48V 2A unit (http://www.hammondmfg.com/266.htm). In this case, is it ok to use a 48V rather than 44V?
by Craig
Wed Mar 07, 2007 6:47 am
Forum: General Discussion
Topic: Question about Capacitors
Replies: 5
Views: 1400

Question about Capacitors

If a schematic calls out for a capacitor of a value of 47uF 16V, would it be ok to use a 47uF 25V capacitor instead? I am specifically refering to what is called for in the PSU project in the March N&V issue. In general, is the capacitor voltage rating on a schematic a minimum value or a specific va...
by Craig
Thu Mar 01, 2007 8:10 am
Forum: General Discussion
Topic: Measuring temperature drop from an intercooler
Replies: 24
Views: 5738

Thanks for info about Omega, I have sent away for their books!
by Craig
Wed Feb 28, 2007 7:09 am
Forum: General Discussion
Topic: Measuring temperature drop from an intercooler
Replies: 24
Views: 5738

Just use two thermocouples. You can buy thermocouple wire from Omega or find some on surplus market and make your own cheaply. You shouldn't need a Cold Junction compensating circuit because you don't care about the absolute temperature, you just care about T1-T2 so the cold sides will cancel out. ...
by Craig
Wed Feb 21, 2007 3:23 pm
Forum: General Discussion
Topic: Measuring temperature drop from an intercooler
Replies: 24
Views: 5738

Your trying to measure the turbo via the intercooler, that’s irrelevant That is NOT what I am trying to measure. Really, the existance of a turbo is irrelevant for what I want to measure. You measure the intake of the intercooler VS the exhaust of the intercooler Yes, that is what I am trying to ...
by Craig
Wed Feb 21, 2007 5:52 am
Forum: General Discussion
Topic: How to record music on dvd media?
Replies: 2
Views: 1014

Are you talking about saving the music in audio CD format or DVD Audio format?