Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by hrc

  1. hrc

    electric door solenoid

    The company I am consulting for would *prefer* a solution that has already been in production, thus cutting the costs of developing that portion of it, and rather spend its resources on the other parts of the design. As for the other questions Think of a standard deadbolt lock in size, perhaps...
  2. hrc

    Prototype PCB

    If you dont need silk screen, solder mask, etc www.barebonespcb.com bout as cheap as I've seen em.
  3. hrc

    60Hz and VFD Feeder in same conduit

    I've done that...put VFD's in the same panel as regular starters BUT...like all control signals, etc I followed the best practices. Ran the signals away from the normal high power stuff, crossed at 90 degree (helps prevent cross coupling) and used shielded cables. So alot comes down to just...
  4. hrc

    Power electronics resources

    All depends on what you are trying to design. Probably the best places to start with are the semi mfg websites. www.linear.com for Linear Tech. Great on giving demo boards www.national.com again a great source, webbench can simulate www.maxim.com - never use them for production but great for...
  5. hrc

    electric door solenoid

    I'm going to cross post this in several groups...so I aplogize in advance but it does cover several areas. I am searching for a source that can provide a door lock solenoid, but its a little different (maybe?) than the normal one. I need the ability to use a key to unlock it normally, but on a...
  6. hrc

    capacative sensing

    In reponse to the first...google....been there...all we get is the mft sites of sensors. What is needed is something that describes (white paper?) on contactless sensing using capacitive sensing. Itsmoked touched on it but need more detailed information if possible
  7. hrc

    capacative sensing

    posting for another engineer who is looking for techincal information on how capacative sensors work. Links to discussions, white papers or sites. Thanks
  8. hrc

    Types of Microcontrollers

    ahhh..but...just found out today something new about PICs A/D. In general, the I/O pins are very robust. We've even have put 9 to 12V on them and sure they get warm (ok..HOT) but they keep on tickin. BUT..the analog pins are not as robust. They tend not to clamp transients very well, let...
  9. hrc

    Remind me...current flow on single ended 3 phase loads

    Just thinking....what about unbalanced loads? say 12A on one leg, 14A on another and 16 on the third? A 208*12=2496 B 208*14=2912 C 208*16=3328 So AB = (2496/(208*1.732)) + (2912/(208.1.732)) = 15A ??
  10. hrc

    Remind me...current flow on single ended 3 phase loads

    OK..that makes sense. I've done some measuring but at lower currents and the delta difference is harder to see there, but makes sense. Thanks again guys, appreciate the help
  11. hrc

    Remind me...current flow on single ended 3 phase loads

    I am pretty sure we discussed this before....but I was trying to run thru my notes and did a search but didnt find what I was looking for. Given a 208wye system, leg to leg connections to a load (single phase load). Each load draws 14A. So, if I have 3 loads, balanced across the legs...
  12. hrc

    Design guides for Class I Division I

    Looking at doing a design of a controller board that is going to need a Class I Division I certification. Anyone know of basic guidelines on designing equipment for these applications?
  13. hrc

    Looking for an OEM phone module

    Yet another strange request (guess thats why consultants get all the strange ideas thrown at them). Client is interested in a project, where one piece of it is a good old telephone. Not a modem, but to have a micro dial a number and then the user picks up a handset and talks. I've been...
  14. hrc

    entry level design work

    All depends on what part of the country you are in. Certain areas are hiring, others are not. We couldnt find certain types of engineers for the life of us about 6 months ago. Its getting your foot in the door. Might check out smaller companies as well just to get some experiance. Might...
  15. hrc

    Looking for a LCD graphics touchscreen

    Looking for a source for a high res monochrome LCD touchscreen, something around 4"x5", and low cost. This will be driven from a microcontroller so serial interface would be nice but no particulars. I can't use a surplus unit, since this is for a potential high volume application.

Part and Inventory Search