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MP
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Posts posted by MP
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I am pleased to see Zeppelin is a new moderator. Welcome to the moderator group!
MP -
Dears,
Which transistor/s should be used (how?) for creating a "not-gate"?
And what should be the arrangement in order to cut-off the circuit if there is a specific signal? (using not-gate)
Vivek v
Perhaps this drawing makes it more clear?
MP
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Mohammadamirbazr,
Please ignore those who want to argue about religion.
Have you looked at Atmel AT43USB353M? It might be what you are looking for.
MP -
These are all good tips no matter what project you are working on. Thanks for sharing with everyone.
MP -
Iagree some of the projects needs repair, but they only need repair, not redesign. These projects were posted because they worked and someone wanted to share. They are not some idiot's bad joke. Unfortunately, mistakes happen when inexperienced people document their projects. Actually, it happens to experienced people, too.
One example is the inverter project which only needed a couple of lines redrawn on the schematic and the decimal places changed on the cap and resistor for the 4047. I have redrawn this one, but since it has turned into a heated up mess, I have decided to not post until it has the advantage of bench testing.
Back to the topic: I would also like to see more moderators for unmoderated areas. If you have candidates, I think you can just email mixos.
MP -
I totally agree. Many times, I see posts that should be removed in an un-moderated area. It would serve the site better to have someone watching each board on a frequent basis.
MP -
audioguru WAS a moderator and was doing a poor job of it.
Also, it is not good to have a moderator who continues to put down the site he is moderating and complains about projects not working correctly which he has never built but others have built and report that they work fine.
(don't get me started on this subject)
MP -
It is my understanding that allowio is part of porttalk. Just download porttalk. You can find several links through google.
MP -
This topic has been moved to Circuit/General Requests.
[iurl]http://www.electronics-lab.com/forum/index.php?topic=6263.0[/iurl] -
I agree. It is hard to know if you wasted time when there is no response from the other end.
MP -
I have also noticed the one-time posts, but I think they should not be deleted since someone else might have the same question. It is hard to tell if the OP has returned or not. I had the impression that some will see the answer and not post again.
MP -
Hello! do you have any ideas on how to know whether your wall plugs are properly earth grounded considering they are already three prong outlets?
There will be no voltage between the third prong (Uninsulated or Green wire) and the return (White Wire). Also, you should have full potential between the Hot (Black Wire) to Return (White Wire) and also see full potential between the Hot (Black Wire) and the Ground (Green or uninsulated Wire). This should be the same potential. You should also see no potential difference between the wall plate screw and Return or Ground. This tells you that the receptacle box is also grounded. The Return and Ground follow separate paths in the wiring, but are connected at the power box where the ground will save you if you have an open in the Return. (Provided that the appliance is setup for this protection).
Hope that helps. To insure the ground is always working, you can install a GFCI type receptacle, which will open up the circuit in the event that the ground is not good.
MP
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I agree. Have you asked Mike about this? I will notify him of this topic.
MP -
You should post a location since International shipping would not be worth while.
MP -
Ok... So I'll use a 10uF outpur cap... Solves the overshoot problem maybe?
I still want to use as small a cap as possible. Can I get away with a metallized film cap or maybe a X7R ceramic cap?
_OR_
is electrolytic the only way to go for the output cap?
I assume you are trying to use as little board space as possible? I design with "surface mount" tantalums instead of "through hole" Electrolytics in such a case. Solves many other problems as well.
I would not recommend metallic or ceramic caps for power supply bypass.
Hope that is helpful.
MP
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Hey gogo,
Sorry for the late reply. I was on a business trip in Asia for the week and just got back this morning.
Here are the eagle files for both schematic and board. Feel free to make any changes you need. This zip has a parts list for the LEDs used in the design if you would like to use them. Otherwise, you might have to make changes to the schematic for the one you want to use. Also, you might be able to use one of the edit commands to just use a different package in the board layout.
MP -
Not really a good idea, but if you do this, you will need to clean the board with alcohol, flux all parts that you will heat, then clean all the flux off the board when finished and apply a conformal coating to the board to re-seal all of the solder connections so they do not corrode.
MP -
How much charge did it provide? Full battery for a reasonable lifespan? Sometimes AC pulses will give you what looks like a revived charge circuit. You can sometimes bring a dead battery back to life by pulsing the charge voltage to it. If the battery only took a little more charge, it is possible that this is what you saw. If the battery now boasts a full charge and the charging system is no longer failing, then I would agree with the comments above about a cold joint or cracked solder pad. In this case, you should get out the magnifier and see what needs reflow.
MP -
Don't stare at it too long.... ;D
As I understand it, the dots will start to connect.
MP -
just curious why you chose transistors for a car alarm instead of digital gates, like OR gates and AND gates to make some logical choices of when and why an alarm is set.
MP -
It's a double sided board. I think you are trying to mount them on the wrong side.
MP -
acdc,
Is there a chance that this unit has a schematic attached inside that you could scan and post? It would be much more helpful to see how it is already setup.
As ante has mentioned, there are too many parameters to be able to give a "one size fits all" type of answer.
MP -
You cannot measure continuity through the RS232 driver circuit. You will need to follow the pulse stream and see where it ends.
MP -
I run mine on Win98. Also, I use an old computer power suply for the power source. I felt there was no point in re-inventing the wheel since I had a few old computers sitting around not in use.
What software will you use? I wrote an X,Y type program that I can use for making my own drill files, but it does not optimize the run nor does it read gerber files. Just curious what everyone is using these days. I built my CNC a number of years ago. It does not use the UCN chips. Uses L297 and L298 combinations.
MP
Moderators for all boards! (If possible)
in Moderator's board
Posted
John,
Mixos makes the decision. I do not think he saw your conversation.
MP