Replacing the tin can style 741 opamp

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LOGICCONTROLS
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Replacing the tin can style 741 opamp

Post by LOGICCONTROLS » Sat Jun 21, 2008 8:18 pm

Hello there:

I am new on this post. I been tinkering with this old senitive vibration sensor. i am trying to replace this tin can style 741. there not much room
in this enclosure to add a protoboard with modern 741. any sugestion
please? :sad:

Robert Reed
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Post by Robert Reed » Sat Jun 21, 2008 10:07 pm

Why not just replace the exact part. They are still avalable. The part you want will have the suffix H after it to designate the metal can style.

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jollyrgr
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Post by jollyrgr » Sun Jun 22, 2008 5:03 am

I can see your concern as on eBay you can get 25 741 in a DIP package for $7 including shipping. A single can is $10.

Pinouts are the same so why not solder short leads to a DIP?

http://www.national.com/mpf/LM/LM741.html

Note the diagram in the above link shows the tab on the can designates pin 8; the dot on the DIP pin 1. Other than that these are lead for pin the same connections.
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MrAl
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Post by MrAl » Sun Jun 22, 2008 5:53 am

Hi there,


I agree that the 741 metal can type can be replaced with a standard
dip package with a little soldering, except when the device has to
run in a high ambient temperature environment. The metal can allows
heatsinking which reduces the die temperature and this allows the
device to run in higher temperature environments than a dip or
SOIC package case would allow. If not high temperature though i
would bet a standard dip package would work just as well, with some
careful lead soldering as jolly suggested.
You might even find a dip to 8 pin circular pattern adapter board
on the web with a search.

http://www.arieselec.com/Web_Data_Sheet ... /18012.htm
LEDs vs Bulbs, LEDs are winning.

Robert Reed
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Post by Robert Reed » Sun Jun 22, 2008 10:34 am

The trouble with adaptors is they are horrendously expensive. These TO -5 styles are available in many secondary suppliers and aren't that expensive. Right off the top of my head - UNICORN ELECTRONICS ---$1.99. But many others carry them and Jameco still had them last time I caroused their catolog ( several months ago).

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Janitor Tzap
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Post by Janitor Tzap » Sun Jun 22, 2008 7:22 pm

I agree with MrAl,

You should get the same 741 OP Amp in the steel can.
But not just for the reason of heat.
But for shielding out RF interference.

If you sub in a 741 Dip Style case.
Any signals from the sensor maybe getting drown out by noise that the OP
Amp is picking up from any RF noise source.
{Electric Motors, Sparks from an ignition source, etc......}
Thus, giving you false readings.

Sometimes it doesn't pay to do somethings on the cheap. :)


Signed: Janitor Tzap

LOGICCONTROLS
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thank for all the ideas here

Post by LOGICCONTROLS » Tue Jun 24, 2008 9:30 pm

I want to thank you all for ideas and solutions on 741 opamp.

i went on Jollyrgr I idea; I soldered wires to the Dip package 741

lead and work it in that space. and left the lead short as i can.

it seam to work Quit well and i am going to use that for temporary until

i can get a can style on on ebay. I am please with it because it use a

hall sensor with magnet to detect vibration on my garage door when

some one pulls In my drive way alerting me some one is here.

thank every who post for ideas

Jeremy

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Bob Scott
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Re: thank for all the ideas here

Post by Bob Scott » Wed Jun 25, 2008 1:20 pm

LOGICCONTROLS wrote:I am please with it because it use a hall sensor with magnet to detect vibration on my garage door when some one pulls In my drive way alerting me some one is here.

Jeremy
Now there's an idea!
The garage door makes a huge microphone diaphragm to detect low frequency intrusion....but what happens when the wind blows?

Dean Huster
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Post by Dean Huster » Sun Jun 29, 2008 3:24 pm

Have 10 of the puppies, used, not new. Ever consider asking if someone on the forum would be willing to part with one for the cost of shipping?

Dean
Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).

R.I.P.

LOGICCONTROLS
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I just happen to find a 741 can at aircraft junkyard

Post by LOGICCONTROLS » Sun Jun 29, 2008 6:23 pm

Thank dean:

I just don t realize what the potential on the forum. . sure would ask more questions along the way. i just happen to get lucky and found one at aircraft
junkyard in San Antonio , it a good drive away from spring branch
those sensor came from Atex electronic surplus and it have gain control
adjustment to reduce sensetivty when the wind blows.. but i get occasional
false alarms. but it help me out and i cant hear what goes on around the house and keep me alert

thank every one that can help me

Jeremy

trident
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Post by trident » Wed Aug 20, 2008 5:20 pm

I have some 741s in the can package. PM me with your address and I can mail one to you, no charge

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