please help a newbie out

Discussion in 'The Projects Forum' started by jay.diem, Jan 16, 2009.

  1. jay.diem

    Thread Starter Member

    Jan 12, 2009
    10
    0
    Realize this is a really simple question, but I just want to make sure I'm reading the datasheet correctly.

    Will 22VDC across the coils be sufficient to trip this relay?

    T9AP1D52-24

    Datasheet: here

    Kind of confused about the "must operate voltage" and the "Must release voltage". :confused:

    Thanks.
     
  2. eblc1388

    Senior Member

    Nov 28, 2008
    1,542
    102
    The person(s) putting together the datasheet should be ashamed of making these kind of errors.

    This is the correct(I think) version.

    [​IMG]
     
  3. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    The "engineers" at Tyco think that their relays will operate with a voltage as low as zero V and release with a very high voltage.
    They should go back to school.
     
  4. eblc1388

    Senior Member

    Nov 28, 2008
    1,542
    102
    After a bit of more careful researching on the NET, I have found out more information regarding the issues.

    The same "error" appears on three more Tyco relay datasheets I looked at and also appears on those from Panasonic relay and Omron relay datasheets. So there must be something we don't normally aware.

    Perhaps we have owed the engineers at Tyco an apology.

    I'll give an example to illustrate the situation. Suppose the engineer tests a batch of 5 relays for the min. operating voltages and result comes back as 75%, 70%, 60%, 62%, 65% of nominal rated coil voltage. Therefore it is correct to say that the "operate voltage" is 75% or possibly less. But there is no guaranty that a single relay will operate at 70%.

    Therefore, as a circuit designer, one should design a circuit that ensure the relay operating voltage never go below 75% but as a relay manufacturer, the specification is to show that 75% is the worst case condition and many relays produced will also operate even at lowerr voltage like 70% or maybe 65%.

    This is now a problem of semantic, both of these statements are correct:

    1. Operate voltage is 75% or less. (note: no "MUST")

    2. Must operate voltage is 75% or more.

    So it appears the use of the qualifier "Must" causes the statement #1 to become false.

    I hope this will now put the issue to rest. :(
     
    Last edited: Jan 18, 2009
  5. jay.diem

    Thread Starter Member

    Jan 12, 2009
    10
    0
    Thank you all for your inputs. :D
     
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