4017 driving MOSFETs

Discussion in 'General Electronics Chat' started by Tester71, Oct 31, 2014.

  1. Tester71

    Thread Starter New Member

    Oct 29, 2014
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    Hello everyone.

    I don't have experience with mosfets, and I would like to know if I could use a 4017 IC to drive them directly.
    I have downloaded some mosfet's datasheets, and I think I could drive something like IRF740 directly, for example.....Or maybe IRF3205....etc.
    The mosfet's load could be something like 1/2A (maximum).
    Could I do it directly from one IC output, or do I have to use first a transistor to trigger the mosfet? If the 4017 is capable to drain 200 mA, I think it could be more than enough.....right?

    What do you think about it? :)
    Thanks.
     
  2. Jony130

    AAC Fanatic!

    Feb 17, 2009
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    And supply voltage is ?? If your VDD is larger than 10V, then you can drive a MOSFET directly from 4017.
     
  3. crutschow

    Expert

    Mar 14, 2008
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    The 4017 can directly drive MOSFETs depending upon the frequency and Vdd.

    Standard MOSFETs require a Vgs of 10V to fully turn on. Logic-level MOSFETs require 5V or, in some devices, 3V to fully turn on.
     
  4. Tester71

    Thread Starter New Member

    Oct 29, 2014
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    THANK you, sorry....supply is car voltage....around 12v-13.8v-14v. Thank you for your fast answers Jony130 and crutschow :D
     
  5. Papabravo

    Expert

    Feb 24, 2006
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    This thread may violate AAC terms if it involves ANY modification to a car or it's systems.
     
  6. ian field

    Distinguished Member

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    I keep a regularly maintained motorcycle battery that often gets used for powering projects - which may or may not have anything to do with automotive applications.
     
  7. Papabravo

    Expert

    Feb 24, 2006
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    I use deep cycle marine batteries myself. A normal automotive battery has a voltage of 12.7 to 12.8 VDC. The tipoff in the post was "12v-13.8v-14v" which you might expect from a battery connected to an alternator. It is for the OP to clarify his intentions. What does he plan to use the MOSFETS for?
     
  8. Tester71

    Thread Starter New Member

    Oct 29, 2014
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    Hello again!!! No modification in any car. I built a little circuit to play with my son with a little motorcycle battery at home (556 ic) and I was thinking about putting some flash leds circuit in an old motorcycle. It is just an idea.....maybe don't need to use mosfets. There are thousands ideas to play with...Today I get some mosfets of an old UPS...just to test in my circuit.......I will try on sunday. Thanks again.
     
  9. Tester71

    Thread Starter New Member

    Oct 29, 2014
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    ....besides this....last week I plugged this little circuit in the cigarette lighter just to play with my son at my garage. No modification in any car......he believe he was a policeman in a police car....:p....with only some leds...jaja
     
  10. ian field

    Distinguished Member

    Oct 27, 2012
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    The OP might have been simply quoting the widely published voltage range for a 12V (nominal) lead-acid battery.

    Sometimes you have to be mindful of the fact; a battery fresh off the charger can be significantly higher than 12V.
     
  11. Papabravo

    Expert

    Feb 24, 2006
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    Like I said 12.7V to 12.8V, but not 13.8V or 14V
     
  12. Tester71

    Thread Starter New Member

    Oct 29, 2014
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    As I said, I have just tested it today, and you were right, it can drive directly a mosfet. That was just curiosity....tested in my little breadboard.

    @Papabravo, I didn`t violate any term :) in any car.
    Later I will make a little circuit for a toy with some leds, powered by a little 9V battery (obviously without mosfets).
    Thank you.
     
  13. ian field

    Distinguished Member

    Oct 27, 2012
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    You can split hairs till the term "automotive" becomes obsolete - to some people 12V is 12V its as simple as that, ask 10 different people what the voltage range of a lead acid battery is and you'll probably get 10 different answers.
     
  14. ian field

    Distinguished Member

    Oct 27, 2012
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    With a CMOS driving a MOSFET, 9V shouldn't cause any difficulty unless the full load runs off it too and pulls it down - you probably need to take into account; an end of life voltage of around 7V ish.

    Most power MOSFETs need around 6 - 8V on the gate to conduct the full headline drain current, but you can still get adequate conduction for many purposes with about 5 - 6V. You can also get logic-level MOSFETs that should be OK with the outputs from a 5V TTL chip.
     
  15. Papabravo

    Expert

    Feb 24, 2006
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    If you want a forum where anything goes and there are no rules or moderators; you're more that welcome frequent those places. We do what we do for a reason even if you fail to appreciate those reasons.
     
  16. ian field

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    Oct 27, 2012
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    Not too sure that jumping to the conclusion that anyone sourcing current from a 12V lead acid battery must be messing with a car, entirely sits well with that sentiment.
     
  17. Papabravo

    Expert

    Feb 24, 2006
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    I never said "it did", I said "it may" there's a difference. As you can see the OP clarified the situation. I'm OK with that are you? Is there a reason you want to keep this going?
     
  18. ian field

    Distinguished Member

    Oct 27, 2012
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    I've made my point - whether it did any good remains to be seen.
     
  19. Tester71

    Thread Starter New Member

    Oct 29, 2014
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    :)
    I can not understand why you keep arguing .... I will not modify my car, and I respect rules.
    My only test was in my breadboard....still in it. People as smart as you should not waste time arguing about such a simple thing . I apologize for my English ...... it is not my native languaje and I have some difficulties trying to express myself in a clear way, and trying to avoid misunderstandings.

    Thanks for your help on technical issues. Be nice ;)
     
  20. ian field

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    Oct 27, 2012
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    I was trying to clarify whether any project prototyped using a 12V lead acid battery, was automatically deemed to be a banned automotive modification.
     
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