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

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
???
05/05/05 12:43
Read: times


 		 #92987 - Elementary, my dear Watson
Responding to: ???'s previous message
For low frequency inputs, re-arranging your R & C so that you get a low pass filter helps to protect against ESD as well as giving some overvoltage protection. Be aware of the effect of this R & C as it affects risetime!

Excellent protection and when followed by a schmitt trigger such as the '14 the risetime problem disappears.

My "standard" switch detect is 10k in series with the input and 1nF to ground at the input pin of the 74HC14 never blew such an input by ESD. Did, however blow one or two by applying 24v DC.

Erik

List of 40 messages in thread
TopicAuthorDate
Your opinion about port config pls.            01/01/70 00:00      
   Its irrelevant            01/01/70 00:00      
      Can you clearify pls?            01/01/70 00:00      
         always            01/01/70 00:00      
   More....            01/01/70 00:00      
      Elementary, my dear Watson            01/01/70 00:00      
   Some reference circuits I've looked at            01/01/70 00:00      
      fittness for purpose            01/01/70 00:00      
         I'd second that            01/01/70 00:00      
         The intention is...            01/01/70 00:00      
            on-board, I hope            01/01/70 00:00      
               I2c is forbidden to leave the board...            01/01/70 00:00      
                  I would'nt            01/01/70 00:00      
   The outside world            01/01/70 00:00      
      Sure, you did! ;-)            01/01/70 00:00      
         Multi controller approach.            01/01/70 00:00      
            Some practical restrictions...            01/01/70 00:00      
               concentrate the data            01/01/70 00:00      
               Something like this.            01/01/70 00:00      
                  maybe not needed            01/01/70 00:00      
                     RS485 Stubs.            01/01/70 00:00      
                        two of the same            01/01/70 00:00      
                           Re: Two of the same.            01/01/70 00:00      
                              you are right            01/01/70 00:00      
                  let Geert do it differently            01/01/70 00:00      
                     on data and star            01/01/70 00:00      
                        bus and star            01/01/70 00:00      
                     I prefer 75176 -> RS485 & 75179 -> RS422            01/01/70 00:00      
                        I've got a lot of 75176s in my drawer :)            01/01/70 00:00      
                           What about CAN?            01/01/70 00:00      
                              CAN            01/01/70 00:00      
                                 CAN            01/01/70 00:00      
                                    CAN CAN            01/01/70 00:00      
                                 Challenges, indeed...            01/01/70 00:00      
                                    I would            01/01/70 00:00      
                                    how about Power Line Communications?            01/01/70 00:00      
                                       X10-alike, I suppose?            01/01/70 00:00      
                                          Ya..            01/01/70 00:00      
                                             Always welcome...            01/01/70 00:00      
                                             oops !!!            01/01/70 00:00      

Back to Subject List