Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: Do these relays serve a different purpose?

  1. #1
    Join Date
    Jan 2019
    Location
    Sunshine Coast
    Posts
    61
    Total Downloaded
    0

    Do these relays serve a different purpose?

    Learning electronics at the moment.

    Is there a difference to these relays?

    The diagrams look different so I suspect they may be different, right?

    Screen Shot 2022-06-01 at 8.29.07 pm.jpg
    Last edited by getLuke; 1st June 2022 at 07:30 PM. Reason: Problems uploading an image

  2. #2
    Join Date
    Feb 2007
    Location
    Perth
    Posts
    3,807
    Total Downloaded
    0
    ..
    2011 D4 3.0 SDV6
    1999 D2 V8, in heaven
    1984 RRC, in hell

  3. #3
    Join Date
    Mar 2016
    Location
    North Lakes QLD
    Posts
    1,637
    Total Downloaded
    0
    There is no eraser on the pencil of life.

    Now - 2008 D3 SE 4.0l V6
    Was - 2000 D2 TD5 with much fruit.

    Ray

  4. #4
    Join Date
    Feb 2007
    Location
    Yass NSW
    Posts
    5,551
    Total Downloaded
    0
    They are odd relays as they both appear to have a capacitor across the coil for the solenoid, the purpose of which would be to dampen any voltage spikes generated by the collapse of the magnetic field on the coil when it is deenergised.
    Without knowing the context it is hard to understand why the yellow one is arranged differently, although the black one looks fairly standard except for the cap.

    Regards,
    Tote
    Go home, your igloo is on fire....
    2014 Chile Red L494 RRS Autobiography Supercharged
    MY2016 Aintree Green Defender 130 Cab Chassis
    1957 Series 1 107 ute - In pieces

    Assorted Falcons and Jeeps.....

  5. #5
    Join Date
    Jan 1970
    Location
    Avoca Beach
    Posts
    13,981
    Total Downloaded
    0
    Old RRC (my 91) with injection had the capacitor on the fuel pump relay.
    Regards PhilipA

  6. #6
    BradC is offline Super Moderator
    No one of consequence
    Supporter
    Join Date
    Mar 2018
    Location
    Perth (near Malaga)
    Posts
    2,862
    Total Downloaded
    0
    I suspect they're pretty similar. If you look at the pin numbers, they're the same for the same function on both.

    Generally in automotive relays there's a resistor across the coil rather than a capacitor. The purpose is to try and limit the peak back EMF spike without slowing down the open time like a flywheel diode can. Without anything you can develop voltages > 100V. It doesn't take much of a resistor to knock that down below the breakdown voltage of the driver circuit.

    I've never seen a capacitor across a coil in an automotive setting. No to say they don't exist, but a cap big enough to effect any material change in back EMF is going to slow down both the open and close times and work the driver a lot harder. A cap across the contacts? Absolutely, but not built into the relay.

  7. #7
    Join Date
    Apr 2016
    Location
    Melbourne
    Posts
    4,203
    Total Downloaded
    0
    I'll 2nd Brads assessment.

    resistor(is common on some relays).

    if you look at the pinouts;

    yellow has a switch between pins 3 and 5, triggered by the coil and resistor between 1 and 2.
    black has a switch between pins 3 and 5, operated by the coil and resistor between 1 and 2.

    ie. same.

    There are a few different relays up there if you look carefully.
    Note the grip tab on the top of the relay body. Those two have the diagonal type.
    There are other relays fitted that have a vertical(or horizontal) grip tab instead.

    from what I can see, the horizonal tab relays look to be lower (current) rated than the diagonally tabbed types, otherwise the pole layout appear to be identical. The much thicker poles are on the 1 and 5 position which is the main feed from power to the device.

    If you research more info on relays, you will generally find that they use the pole identifiers of 85, 86, 87, 87a and 30.
    The corresponding pinout from these Siemens 1/2/3/5 pin types to the more usual pin numbering is that pins 1 = 86, 2 = 85, 3 = 30 and 5 = 87.
    if you have a peek in RAVE's electircal section under power distribution, and go to the fuse boxes, the pinouts for the relays use the universal 85, 86, 87, 87a and 30 numbering system.

    Not normally vital info for every day life, but in your situation with your starting/aux delay issue, knowing that if you bridge the main power sockets(ie. 3 and 5 or 30 and 87) on your relay socket(ie. the fuse box part) will power up that system.

    Alternatively: if you fitted a multimeter(or test light) between sockets 1-2 (85-86) and hit the switch for that device, then then you will either see voltage or light when that switch is activated.
    This is just general info on what a relay does, not specific to your issues.

    In your situation tho, those two relays auto power up depending to your key position. So, if you pull say the aux relay, and use a multimeter or test light in pins 85/86(remembering that RAVE uses this numbering system!) then you should see voltage or light once you hit the first click on the key.
    Arthur.

    '99 D1 300Tdi Auto
    '03 D2 Td5 Auto

  8. #8
    Join Date
    Nov 2012
    Location
    Qld
    Posts
    10
    Total Downloaded
    0
    Quote Originally Posted by getLuke View Post
    Learning electronics at the moment.

    Is there a difference to these relays?

    The diagrams look different so I suspect they may be different, right?

    Screen Shot 2022-06-01 at 8.29.07 pm.jpg
    From what I can see in your photo, they look the same to me. The diagrams are just drawn differently. There both appear to be SPST with the same pin number markings in the diagram. Without seeing the bottom, it's hard to tell if the pins are in the same position or not. If the pins are marked with the same numbers in the same position, then I'd say that they're equivalent.

  9. #9
    Join Date
    Apr 2008
    Location
    Brisbane,some of the time.
    Posts
    13,641
    Total Downloaded
    0
    Looking at the pics,the relays switch the same NO contacts,but could have different voltage coils and load ratings.
    Paul

    D2,D2,D2a,D4,'09 Defender 110(sons), all moved on.

    '56 S1,been in the family since...'56
    Comes out of hibernation every few months for a run

  10. #10
    Join Date
    Jan 1970
    Location
    Queensland
    Posts
    7,768
    Total Downloaded
    0
    Quote Originally Posted by getLuke View Post
    Learning electronics at the moment.

    Is there a difference to these relays?

    The diagrams look different so I suspect they may be different, right?

    Screen Shot 2022-06-01 at 8.29.07 pm.jpg
    Hi Luke and both relays are AUTOMOTIVE relays and are the same, only the diagram on each relay is displayed differently.

    The resisters are standard in most AUTOMOTIVE relays these days, to help remove back EMF spikes , as a means of protecting other electronic devices in the vehicle.

Page 1 of 2 12 LastLast

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Search AULRO.com ONLY!
Search All the Web!