×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Touch circuit help needed

Touch circuit help needed

Touch circuit help needed

(OP)
I am trying to find a circuit whereas you touch a piece of stainless steel and generate a 12 volt pulse that is sustained while the pad is being touched. I have circuits for one one touch and timed output, but I can't seem to find a circuit anywhere for what I described.  Any help would be great.  Thanks

RE: Touch circuit help needed

The harder part of this sort of application is deciding the circuit to interface to the stainless steel plate (e.g. doe it use "mains hum" pickup to trigger it, or change in d.c. leakage to ground using a VERY high input impedance amplifier).  

If you say you have some similar circuits (which must provide the "front end") why can't you just omit the flip-flop stage in the push-on push-off circuit, or the timer in the timed output pulse circuit?

RE: Touch circuit help needed

(OP)
I am using the typical 555 one shot circuits for other parts of the interface that don't require a "hold" feature for varying durations.  I am not sure how to adapt the front end of that circuit to cause a stable output but I'll use that as a starting point.  I am not aware of the other concepts you mentioned.  Thanks for the ideas.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources