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Thread: Time relay for CAR-PC...

  1. #11
    MySQL Error soundman98's Avatar
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    then you would need 2 of them, and would need to use a diode.

    or you can look into this controller in the mp3car store:
    http://store.mp3car.com/Micro_Shutdo..._p/pwr-007.htm

    or you can try to PM forum member 'curious' to see if he can make one for you..

  2. #12
    Raw Wave
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    That's a good link soundman....
    IMO that's a great price for what it is. (Even cheaper than Arduino LOL!)

    It's a pity more aren't into circuits though - stuff like this is often the cascading of "blocks" such as timers & edge triggers.
    I'm about to do "a ~2 minutes after power off" power-hold for my voltmeter using a FET & cap (wot?! Not a 555??). But that could trigger and edge detect etc etc (but then use (schmidt) inverters or logic gates etc).

    It's different when one has a cheapish "standard" PIC or uPC platform - then you just program it and plug it in (maybe add a few external FETS, relays etc). But until you overcome those "overheads", it's not practical.

    Otherwise to find versatile yet cheap modules like that Micro Shutdown controller... PRICELESS! (Well, under $50 anyway.)

  3. #13
    MySQL Error soundman98's Avatar
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    you bring up a good point-- pulse timers, should in theory, be easy to build if your familiar with 555 timer chips-- i think the product i linked to is based on one..

    it might not be cheaper, but more interesting to build your own solution..

  4. #14
    Variable Bitrate checksum's Avatar
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    The reason I don't want to use the Micro Shutdown Controller at MP3 store is that is does not have a delay ON, it only has a delay OFF. So it may trigger before power is applied to the device or at excatly the same time, which is not ideal.
    Take a look at this one I found:
    http://www.prosecuritys.com/6062.html
    2005 Nissan Altima - Completed 2007
    2010 Nissan Altima - Coming Soon...

  5. #15
    What can I say? I like serial. Curiosity's Avatar
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    What? Oh yeah, I make one that pulses when the input goes on or off, plus has an optional status input so it doesn't pulse when the ACC goes on and the device is already on (and vise versa). Plus a seperate delay timer for both pulses. But it could probably be built with some resistors, capacitors and relays.

  6. #16
    Variable Bitrate checksum's Avatar
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    Another discussion I found while doing some searches:
    http://www.mp3car.com/vbulletin/powe...will-work.html

    2005 Nissan Altima - Completed 2007
    2010 Nissan Altima - Coming Soon...

  7. #17
    Maximum Bitrate boelle's Avatar
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    I have tried relays with delayed power on and delayed off.... worked fine going from off to on... but the other way gave trouble, i checked everything more than 20 times and when it came to cutting power the relays flipped back and forth like rabits having sex... so to me the quick answer was to have a pic control it, benefits are more simple schematic and option to reprogram it if the times are not quite right, with the picaxe reprogramming can be done without taking the pic out, it are programm by a simple usb to minijack cable (with a usb to serial converter in the usb plug)
    Blessed are the "cracked" for it is they who let in the light.

  8. #18
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    Soundman, don't buy that uSDC, because I bought one and this is not working as it should be. Read the review under the product and this is the truth about the product.

    You should all think about DCDC-USB, because with this product you can define any time you want (and you can define it up to second):
    - how much to wait before giving power to board
    - how much to wait before sending POWER ON button
    - how much to wait before turning ON AUX
    - how much to have IGN canceled when in BOOT mode
    - how much to wait before sending POWER OFF button when IGN is lost
    - how much to wait before taking the power of board

    I had one project here in Slovenia where we installed 130 PCs to public busses and trust me it is not good to allways, even for small stops like gas stations, take the power of board (this is not good for BIOS - sooner or later it will get corrupted). Now we configured that after 10 seconds computer recieves POWER OFF button and DC-DC is suplying power to board for next 2 hours, so small stops does not take the power of board.

    In my personal project I will have configured that power is not taken from board for at least 17 hours, so I will try to avoid taking the power in all my regular days (working days) and if I go on vacation or somwhere for longer time than I would like that power is taken away.

    I have a lot of experiences with Car-PCs and trust me DCDC-USB is one of the best products if you have single voltage supply board.

  9. #19
    Variable Bitrate billmee's Avatar
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    Quote Originally Posted by OldSpark View Post
    billmee - post it anyhow, maybe in a new thread. (For others.)
    The automotive relay I am using includes a snubbing diode.

    This will provide about minute of delay.
    To increase that time add another cap in parallel.

    You could use a smaller Transistor, I chose the Tip31 for it's size/robustness.


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