Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
Erik Malund
02/02/12 15:59
Read: 495 times
Mt Airy, Nc

#185783 - that you had the worst possible reset circuit
Responding to: ???'s previous message
Neil Kurzman said that , “I can assume you have an R/C reset on the 8052?”
Thanks Neil… I’m already using it.
It can’t solve this situation… Because proses ordinary is;
1-R/C Reset
2-8051 Start up ( It’s writing ports to logic-1)
3-My program…

Neil correctly guessed that you had the worst possible reset circuit.
RC reset is horrible and may lead to flash loss. Also with a proper supervisor, you may even be able - while having the pulse longer than the minimum the chip requiers - to have a reset so short that the relays do not click.

Thans Richard. I know them.
8051 I/O maximum output current is 15-20mA (approximitly)

NO!, NO!, NO! some 8051 derivatives have I/O maximum sink current is 15-20mA (approximitly) however mayny derivatives will be specified with less or - a few - with more.

I won’t calculate at length. But, I/O pin output current through to Base pin is approximitly 1,9mA.
However, 8051 can supprot 15-20mA. (approx. 10 times more)
Due to that reason, current don’t have to flow outside to I/O pin.

If I could read what you thought you wrote, maybe I would understand the above.

BTW, yes at first time low-active design was significat.
ULN2003 etc. chips are used. But, some problems are noticed.
Now, Hi-Active usage has started lately. UDN2981 etc..

if you are already using such a chip to drive your relays, connect the suipervisor output to the enable pin and you are home free,

I think, I should use PIC series microcontroller for this kind of circuits….
how is "inactive open" ('input') better than "inactive high" in a previous post you babbled about an open solder joint, what is the difference betheen an open pin and an open solder joint.

Hundereds, if not thousands, have made succesful designs using the '51 to drive relays, it is remarkable that, after dacades,someone pop up that cant.


PS: from the jokers dictionary relay: recycling old girlfriends

List of 34 messages in thread
Power-On Port Status Problem      Adam Blue      01/30/12 08:42      
   Wrong idea      Per Westermark      01/30/12 08:48      
   you will not      Erik Malund      01/30/12 08:49      
   you are not the only one      Erik Malund      01/30/12 09:18      
   ATMEL be ashamed      Adam Blue      01/30/12 15:05      
      No, YOU should be ashamed...      Kai Klaas      01/30/12 16:15      
      Nonsense!        Andy Neil      01/30/12 16:46      
      PIC Does so      Neil Kurzman      01/30/12 23:08      
         Oh really??      Michael Karas      01/31/12 07:46      
            "Glitch" in the sense of kind of "setback in a plane"?      Kai Klaas      01/31/12 10:19      
   Try These Ideas        Michael Karas      01/30/12 17:21      
   "Glitch"      Adam Blue      02/01/12 13:12      
      what is not “ATMEL true”.      Erik Malund      02/01/12 13:37      
      I think you are making excuses      Erik Malund      02/01/12 13:41      
      Oh, boohoo!        Rob Klein      02/01/12 14:04      
      What a bunch of fatty sausage...      Michael Karas      02/01/12 14:59      
      "very easy problem"      Andy Neil      02/01/12 15:02      
   Power-On Glitch      Adam Blue      02/01/12 15:40      
      Nonsense - again      Andy Neil      02/01/12 16:28      
      Please explain what the "power-on glitch" is ...      Richard Erlacher      02/01/12 19:26      
      Into The Frying Pan        Michael Karas      02/01/12 20:52      
      Power-on problem...      Kai Klaas      02/02/12 05:55      
      You are still blaming the tools      Per Westermark      02/03/12 05:55      
   Design the hardware first.      David Prentice      02/02/12 07:21      
      do not Design the hardware first.      Erik Malund      02/02/12 07:30      
   Power-On Glitch      Adam Blue      02/02/12 15:07      
      that you had the worst possible reset circuit      Erik Malund      02/02/12 15:59      
      RC-reset...      Kai Klaas      02/02/12 17:20      
      Sorry, double post, don't know why...      Kai Klaas      02/02/12 17:21      
         No, you're not the only one      Richard Erlacher      02/02/12 21:12      
      Would I Hire?      Michael Karas      02/02/12 22:44      
         incidentially      Erik Malund      02/03/12 07:09      
   Power On satus Problem      Satish S Munot      02/29/12 10:16      
      echo, echo, echo      Erik Malund      02/29/12 10:30      

Back to Subject List