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Recent content by Mike2468

  1. Mike2468

    PID autotune

    Gas or electric heat? If SSR or SCR, can be set to a shorter cycle time. If gas, on/off actuator or position actuator? Slow actuator response = sluggish response. Is your sensor fast? If it isn't bottomed out in the thermowell, could be sluggish response. If the sensor is located near the...
  2. Mike2468

    Stray voltages from VFDs affecting cows

    The www.strayvoltage.ca site is functional via Internet Explorer 7, but not Mozilla. Whatever. The engineer at Strayvoltage was David Rogers, who created the high speed scope so he could monitor farms remotely.
  3. Mike2468

    Stray voltages from VFDs affecting cows

    A Canadian company developed a high speed scope for dairy farm stray voltage monitoring. They are at: http://www.strayvoltage.ca A news article was published in 2007. A copy is at: http://www.strayvoltage.ca/Larry.htm The farmer had VFDs and other items in his parlor. He spent money to...
  4. Mike2468

    Batch process- resistive heater overtemperature safety

    A variation on using a latching, independent system is a "FM Approved High Limit". This is a similar to a PID controller, but the output is always a latching relay. Factory Mutual requires these for high temperature applications, such as industrial furnaces. You can google on "FM Approved High...
  5. Mike2468

    GAS TIGHT SOCKET

    The connector company BERG used GTH (gas tight high pressure)on a variety of connectors (IC sockets, card edge, etc). Back when gold went to $800 in the late 1970s, the thought was that you could use tin plated connectors that had a point of very high pressure, thus making that point gas tight...
  6. Mike2468

    Terminal Burn Outs

    I would recommend a firmer connection such as a screw terminal. A slide-on connection that is exposed to high heat and amperage will only get hotter over time, especially after you use it a few times (such as after heater replacement).
  7. Mike2468

    Terminal Burn Outs

    As stated, there is a massive difference in quality between Fast-on (female) connectors. Stamped brass vs phos bronze, good supplier vs other, etc. In addition, you have a thermal connection that is constantly exposing the junction to thermal stress. If the junction is loose, you will have a...
  8. Mike2468

    Copper theives are stung hard!

    At new homes near us, the model homes all have many internal security cameras wired as web cams. They have caught guys with trucks who are stealing everything -- Sub Zero Fridge, kitchen electronics, everything. Real shame. Everyone loses due to these thieves.
  9. Mike2468

    Testing Electrical Connections

    "on a completed assembly scale" Companies like Amp/Tyco have crimping tools with built-in ratchets so the crimps are always identical. If you use the right wire and the right tool, the crimps were identical. Likewise the Amp/Tyco automated bench tools used machined die sets for the same...
  10. Mike2468

    Relay contact life

    4200 cycles per hour is more than once every second. The electrical life of a mechanical relay will be limited. The solenoid is inductive, the electrical life will be further limited. Use solid state. Google on: odc modules -- for several vendors. Install a high speed diode across the...
  11. Mike2468

    Problem with nonresponsive relay

    The SSR's output has a tiny leakage current. It is not enough to turn the coil ON, but once the coil is ON, the leakage is enough to hold the coil ON, regardless of what your controller is doing. That is why, once you flip the switch in the circuit, the coil drops out as expected. Just add...
  12. Mike2468

    Thyristor as switch off device .

    If you are switching a AC power line, the fastest turn OFF will be at the next zero crossing mark. This could be as much as 8.3 msec (60hz, 10msec at 50hz). If you want to avoid the zero cross limitation, then you may be able to achieve this with an IGBT.
  13. Mike2468

    Need Solid Sate Relay Part # 101702 Help Please!!

    The device is probably a variation of a one-shot solid state timer. See: http://www.amperite.com/Uploads/stb.PDF (or google "solid state timer") for examples. They "might" have something close to what you are looking for. If not, then a solid state timer feeding a latched SSR, with the...
  14. Mike2468

    Need Solid Sate Relay Part # 101702 Help Please!!

    Date code is probably 16th week, 1991. 101702 almost sounds like a local part number. Otherwise, you'd have a manufacturer's name, UL, etc. A digital picture or a definition of what it is suppose to do would be the next step. The small 4 pin connector goes to a position sensor and what else...
  15. Mike2468

    Can you Identify this Terminal?

    AMP/TYCO or Molex would typically have their own mark where the arrow is. The product is probably from a less known vendor. Being tin plated, the application might be appliances or other lower priced products.

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