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  1. Minder

    The Day The Symbol Changed

    I notice the description of the symbol they use throughout is correct. .... Earth. Unfortunately when various National & International standards are in place and the users of that particular discipline either ignore or use alternatives there is no longer a Standard and confusion reigns.:( M.
  2. Minder

    The Day The Symbol Changed

    It must be a N.A. thing.!;) After looking up some of my old original academic reports from the U.K. and some manufacturers example product circuit manuals of the time showing valve and semi-conductor circuits, I can see why I feel comfortable with the present standard, they all conform to the...
  3. Minder

    The Day The Symbol Changed

    The oldest copy I have of the JIC Electrical Standards Va. (US) is 1960 and that still shows the symbols as in post #7. Right up to the current day NFPA79 2015. All the CAD and Schematic capture programs I use have the same symbols, Kicad, Orcad etc. They most likely came to be misrepresented...
  4. Minder

    The Day The Symbol Changed

    The history of industrial standards goes back to the JIC (Joint Industrial Standards) of 1919 in UK. Later in N.A. from 1955 where the various symbols for electrical drawings was defined, later to become NFPA79. Fortunately I still deal with companies that supply drawings based on these...
  5. Minder

    The Day The Symbol Changed

    To me that outlines the whole problem, you have an international symbol that indicates an Earth Ground connection, then everyone uses it regardless of whether the point is actually earth ground or not. So that leaves the viewer of the circuit, unsure of whether an earth ground connection is...
  6. Minder

    The Day The Symbol Changed

    A pet peeve of mine. See recent post. https://www.electronicspoint.com/threads/difference-between-ground-and-ve-voltage.277846/ One of the biggest offenders is the well known 'Art Of Electronics' which use it throughout the book, so naturally all aspiring students think this is the way it is...
  7. Minder

    Killing SSR (relays) - Need to understand

    There is a lot of knock off stuff coming out of China, I generally stick with Opto22 they haven't let me down yet. M.
  8. Minder

    Killing SSR (relays) - Need to understand

    I will make sure to stay up.:) M.
  9. Minder

    Repair relay

    You can get one on ebay for $12.50 PP. Not worth to rewind. The reason you probably 'found' it was because it was burnt out.!! You are always better to go with DC devices such as relays and solenoids, they are not so prone to burn out.! M.
  10. Minder

    TFT Screens (LCD)

    If you are lucky you can find the OEM's spec sheet and this should tell you the interface addressing. What make? Sharp was one old popular make. M.
  11. Minder

    Building safety garage door project.

    I am assuming you are looking for a safety limit? Similar to a G.door to reset to the up position or a blocking/ hazard detection.? M.
  12. Minder

    3 phase generator

    Any schematics or anything else to go on? Not many mind readers here! M.
  13. Minder

    Help Programming 16x2 LCD - PIC16F73

    If you go to the Microchip site and search for the demo board Pic demo-2 the S.W. is there in assembly and C for the ver2 of the board. Ver1 just has Assembly. All of Microchip development boards have schematics and software for each...
  14. Minder

    Help Programming 16x2 LCD - PIC16F73

    Look up Microchip LCD app note AN587 it is an old one but covers 4 bit and 8 bit LCD programming. There is also a list of app notes here. http://pic-rosa.blogspot.ca/2007/09/source-code-for-pic.html I only have C source code for the 18F series. M.
  15. Minder

    PIC16F877, 250Hz PWM

    Yes of course, I was thinking of capture, you can go down to 1.2Khz with 20mhz system clk is that too high? What is the application? M.
  16. Minder

    Help Programming 16x2 LCD - PIC16F73

    That is a method of table read for the 16F series. I found the 18F series much better to use as they have quite a few features and advantages over the 16F series, especially programming in Assembly. If you are still getting problems with proven code, could it possibly be a hardware issue? M.
  17. Minder

    PIC16F877, 250Hz PWM

    Then you may have to use a low freq clock in such as external osc or crystal input, I have used the 32khz watch crystals for some low freq apps to run TMR1. I would think the 16F877 has this feature. M.
  18. Minder

    Killing SSR (relays) - Need to understand

    Measure the heating element at the SSR input, some meters also have a peak store feature. M.
  19. Minder

    Killing SSR (relays) - Need to understand

    You really need a clamp on ammeter they come as attachments for DMM's. M.
  20. Minder

    Hook Up Wire for PSU

    Refer to NFPA79 for wire colour and ampacity. What particular environment are you working in? M.
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