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Re: [Openeeg-list] TLC 277IP is wrong component !!!!!!!
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From: Orcher <ee...@my...> - 2003-07-30 14:52:11
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It could be same assembly error, in this moment i have to regard to everything. I will reacheck ever component as well. By the way, i have put same pic of my device and the electricguru prt.screen in the web, it maybe help a bit. My amp.boardhttp://213.66.1.192/amp.board.jpg the digit.boardhttp://213.66.1.192/digi.board.jpg Prt.screen of electricguru before and after i change the tripod (in this case channel 1). But it is the same resulte for channel 2. Before http://213.66.1.192/eeg1.jpg After http://213.66.1.192/eeg2.jpg Dir.http://213.66.1.192/Thanx joe and jake.. i will try more to find the error.--- On Wed 07/30, Joe Street < js...@ve... > wrote:From: Joe Street [mailto: js...@ve...]To: ope...@li...Date: Wed, 30 Jul 2003 09:34:56 -0400Subject: Re: [Openeeg-list] TLC 277IP is wrong component !!!!!!!I have been following this thread. I wonder if the amplifiers are oscillating due to some assembly error?? If so, adjusting the pot would likely change an RC time constant somewhere in the feedback path, affecting the frequency of oscillation. What is the frequency range you see on eguru when you adjust the pot? Does this output appear only when the cal signal is connected? I don't have these different devices so I cannot make a test but if it is the different internal bias network which is giving you this problem, you should be able to determine this by substituting almost any dual supply op amp with the same pinout such as TL072 etc. which should be available at any decent electronics supply in your country. The device may not have the same noise performance and offset spec but it should still amplify the signal properly. Try shorting the inputs of your analog board to VGND and confirm that the traces on eguru go to flat lines. Also see if there is any periodic output signal with inputs floating or connected together through say 100 Kohm resistor.My understanding is that the TLC277IP and CP are just industrial vs commercial temperature range versions of the exact same device. I don't think they are single vs split supply variants. Check your board against the schematic very carefully, as I suspect you may have some components installed incorrectly or a solder bridge somewhere. Sometimes you can look at an error over and over and the brain does not recognize it as an error but keeps making the wrong assumption every time. It may help to have a partner and one one follows the schematic while the other checks the board.JJake wrote: From: "Orcher" Actually the TLC277IP stand for Single-supplay and the TLC277CP for Dual-supply. They may work witch each other, but not correctly.You can read more about it here. Iam not so skilled in electronic enginey, so i dont know if there is a suitably way to modify the tcl277ip to work as tlc277cp.If there is, iam greatfull to know. you will spear me same $ :). In light of your post, I did another check. I adjusted the gain on the channel up and down (P202). It seems to perform the same with either component. Also, the channel didn't need adjustment when I switched from the CP to the IP. I'm not sure what to make of these results... -Jake ------------------------------------------------------- This SF.Net email sponsored by: Free pre-built ASP.NET sites including Data Reports, E-commerce, Portals, and Forums are available now. Download today and enter to win an XBOX or Visual Studio .NET. http://aspnet.click-url.com/go/psa00100003ave/direct;at.aspnet_072303_01/01 _______________________________________________ Openeeg-list mailing list Ope...@li... https://lists.sourceforge.net/lists/listinfo/openeeg-list Go to the above address to change your subscription options, e.g unsubscribe. _______________________________________________ No banners. No pop-ups. No kidding. Introducing My Way - http://www.myway.com |