Search found 85 matches

by unknown_entity
Fri Apr 14, 2006 6:35 pm
Forum: General Discussion
Topic: Instrumentation Amp issues
Replies: 11
Views: 3854

Just an update for anyone interested,


i did get an in amp working using 3 seperate op amps, but i am choosing to go with an IC version for several reasons.

For now im am still testing the AD8221 it is a high bandwidth/precision IC in amp.
by unknown_entity
Wed Apr 05, 2006 7:37 pm
Forum: General Discussion
Topic: Instrumentation Amp issues
Replies: 11
Views: 3854

:D Thankyou for the advice everyone, im an undergrad doing this as a small project for the physics department at my local college. I really haven't had to work with amplifying signals at such a low level while worrying about noise and bandwidth too much, so this is a learning experience/refresher fo...
by unknown_entity
Tue Apr 04, 2006 9:12 am
Forum: General Discussion
Topic: Instrumentation Amp issues
Replies: 11
Views: 3854

Instrumentation Amp issues

For a project im working on i am using strain 350Ohm strain gauges in a bridge configuration to measure the pressure wave created in ballistic gelatin. I need an instrumentation amp capable of doing 0-500Khz as far as bandwidth is concerned. I have tried my hand at building a classic 3 op amp instru...
by unknown_entity
Mon Oct 24, 2005 11:56 am
Forum: General Discussion
Topic: voltage and current regulation
Replies: 15
Views: 6097

Re: voltage and current regulation

thanks for the input everyone... i ended up just making and adjustable current reg using an LM7805. The whole point of having a voltage reg was just to make the whole thing more idiot proof once it is built.(since it would be used by people other that myself)
by unknown_entity
Tue Oct 18, 2005 4:49 am
Forum: General Discussion
Topic: voltage and current regulation
Replies: 15
Views: 6097

Re: voltage and current regulation

To Chris & Hack...<p>I basicly building a scaled down benchtop supply. Because i'll be using V and I regs it run in either constant current or constant voltage mode depending on which reg is the limiting factor.
by unknown_entity
Tue Oct 18, 2005 4:46 am
Forum: General Discussion
Topic: voltage and current regulation
Replies: 15
Views: 6097

Re: voltage and current regulation

it's a lighting source for micro endoscopy. Now we're just running a demo model. I recently switched over from a high power xenon lamp to a special led for the lighting source.<p>So im just looking for a supply where i can tweak it to account for different led's or arrays. And the current limit is r...
by unknown_entity
Mon Oct 17, 2005 2:55 pm
Forum: General Discussion
Topic: voltage and current regulation
Replies: 15
Views: 6097

Re: voltage and current regulation

yea i got it... Thanks again Chris. It's pretty much the same as the circuit i saw before but it lookd odd to me at first because of the resistor in series with the output.<p>What im thinking does all the output current pass thru this resistor, if so i'll have to use a fixed one for a proper power r...
by unknown_entity
Sun Oct 16, 2005 11:54 pm
Forum: General Discussion
Topic: voltage and current regulation
Replies: 15
Views: 6097

Re: voltage and current regulation

chris, i sent you an email to the addy in your pm
by unknown_entity
Sun Oct 16, 2005 9:14 pm
Forum: General Discussion
Topic: voltage and current regulation
Replies: 15
Views: 6097

voltage and current regulation

OK... the big picture of what i want to do is regulate the voltage and current independantly to a LED. This is a special purpose application and i already know i have to regulate both voltage and current.<p>I already know how to work with linear fixed and adjustable voltage regulators like the LM317...
by unknown_entity
Sun Jun 19, 2005 7:42 pm
Forum: General Discussion
Topic: How do i select the right MOV?
Replies: 7
Views: 2573

Re: How do i select the right MOV?

Since MOVs are basically self destroying im guessing it would be better to place them behind an EMI filter to prolong their life.<p>I found a little bit of onfo on the joule ratings of MOVs. http://www.surgex.com/library/62001.html http://www.techsavvy.com/industry/file/national/03v0r/pwc06.html?id=...
by unknown_entity
Sun Jun 19, 2005 7:06 pm
Forum: General Discussion
Topic: How do i select the right MOV?
Replies: 7
Views: 2573

How do i select the right MOV?

I need to use MOVs for transient suppression of the 120V line in a power supply i am working on. I am fairly sure i know how to select the proper voltage rating but i am not sure how to select the proper “power dissapating” rating. If i remember correctly(is this correct?) i only need 3 MOVs, 1 from...
by unknown_entity
Tue Aug 26, 2003 11:41 am
Forum: Computer Programming
Topic: MC68HC11 Refrence Books
Replies: 2
Views: 2018

Re: MC68HC11 Refrence Books

hey thanks for the link. i just found out today that we will bw getting som hasndbooks and manuals free from motorola
by unknown_entity
Wed Aug 20, 2003 4:12 pm
Forum: Computer Programming
Topic: MC68HC11 Refrence Books
Replies: 2
Views: 2018

MC68HC11 Refrence Books

Can anybody recommend some good reference books that cover the basics of programming on the MC68HC11. Im looking for a suppliment to the textbook I already have.
by unknown_entity
Tue Jul 01, 2003 6:48 pm
Forum: General Discussion
Topic: optical interrupt for rate of fire.
Replies: 4
Views: 1628

Re: optical interrupt for rate of fire.

http://www.tippmann.com/markers/image/a5t.jpg <p> http://www.tippmann.com/systems/image/egrip/egrip.jpg http://www.tippmann.com/markers/default.asp Yeah all that and full auto. I really dont care about measuring the speed because all the fields have chronos. I just wanted a quick way to tell rate o...
by unknown_entity
Mon Jun 30, 2003 6:27 pm
Forum: General Discussion
Topic: optical interrupt for rate of fire.
Replies: 4
Views: 1628

optical interrupt for rate of fire.

I plan on using an IR or bright red LED with a Photo transistor to make a rate of fire meter for my paintball gun. <p> Ive got the basic idea and a schematic but does anyone know what the radioshack photo transistors would be most sensitive to red or IR light? <p>I'm actually cheating on this projec...