1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Momentary lockout Solenoid

Discussion in 'Homework Help' started by syntax_x, May 21, 2013.

  1. alec_t

    alec_t Well-Known Member Most Helpful Member

    Joined:
    Jul 10, 2011
    Messages:
    9,315
    Likes:
    1,230
    Location:
    Cardiff, Wales
    Yes, 24v is too high.. My bad. Use a lower voltage supply.
    M1 is an N_channel MOSFET. R4 is there to damp any oscillation.
     
  2. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
    Will the circuit still work with a 5v feed at a much lower current?
     
  3. alec_t

    alec_t Well-Known Member Most Helpful Member

    Joined:
    Jul 10, 2011
    Messages:
    9,315
    Likes:
    1,230
    Location:
    Cardiff, Wales
    The relay would need to be a 5v coil type and the MOSFET M1 a logic-level N type.
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia

    The relay is 5v coil type. I'll grab the MOSFET today and try it out.
    Thanks.
     
  6. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
    What value does the pot change?
     
  7. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
    Alec-t, the .asc file you linked with the image of the 555 circuit do not match.

    The .asc file has a 250k pot and only 1 470n cap, the other is a 1uf cap.

    Setting the circuit up the way the jpeg is does not simulate.

    I have ran 2 separate sims that i think will work for me

    The first is basically the same as your first alec-t
    New 555.jpg

    The second circuit replaces the 1k resistor with a 20k, which seems to knock out any future solenoid activation while the trigger is depressed.
    555 timer 2.jpg

    The 1uf cap should of been labeled "1u" in both pictures sorry.
     
    Last edited: May 31, 2013
  8. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
    Heres what im hoping will work for me, it allows me to tune the single inputs response via the 250k pot

    View attachment 73933
     
  9. alec_t

    alec_t Well-Known Member Most Helpful Member

    Joined:
    Jul 10, 2011
    Messages:
    9,315
    Likes:
    1,230
    Location:
    Cardiff, Wales
    Will take a look when I get back from hol.
     
  10. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
  11. alec_t

    alec_t Well-Known Member Most Helpful Member

    Joined:
    Jul 10, 2011
    Messages:
    9,315
    Likes:
    1,230
    Location:
    Cardiff, Wales
    The link in post #27 is invalid. Can you repost? BTW, the pot is there to adjust the time for which the solenoid is energised, to allow for the current to build up in the coil and for the solenoid to pull in. The lockout time is determined by R1C1. R2 is there only to limit discharge current through the switch, to prolong the switch contact life. It has nothing to do with the timing and its value is non-critical.
     
  12. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
  13. alec_t

    alec_t Well-Known Member Most Helpful Member

    Joined:
    Jul 10, 2011
    Messages:
    9,315
    Likes:
    1,230
    Location:
    Cardiff, Wales
    Just use an inductor in the sim; say 100mH and 100Ω series resistance.
     
  14. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
    Why is the distance between the 1st and 2nd pulse always larger than the 2nd and 3rd.

    Considering my config I should just be able to ground your trig as the circuit is only powered by my trig closed.
    Also, do you think I should put a diode on the +5v connected to ground?
     
  15. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
    Ive update the following link with an inductor used as the relay but still cant run it in the sim.
    http://www.eugene.kizza42.com/Arcade/GunDrive.asc

    I removed the trigger and r1 from your original post alec-t and when running 250k pot at 180 its gives me a one shot pulse of.2 seconds upon power up.
    http://www.eugene.kizza42.com/Arcade/Alec-t-Gundrive.asc

    So everything should work fine im gathering, i received the nMOSFEsS today, logic level ones,
    as soon as i look thru the data sheet and find the pinouts for the nMOSFET ill solder it in and give it a go.
     
  16. alec_t

    alec_t Well-Known Member Most Helpful Member

    Joined:
    Jul 10, 2011
    Messages:
    9,315
    Likes:
    1,230
    Location:
    Cardiff, Wales
    Sorry, my bad. I hadn't checked your asc file when I replied about the relay simulation. :eek: Ignore that reply.
    I'm afraid your config in the post #31 link won't do what you want as you have trig grounded and the relay isn't simulated accurately.
    The FET does the switching of the solenoid, making a relay unnecessary. You could use a relay instead of the FET.
    That's just because of the way the sim is set up with a 0.2sec delay on the simulated trigger pulse. You can easily alter that if you wish. At power-up the 555 circuit is triggered, causing a spurious activation of the solenoid. That could be prevented by adding suitable components to the Reset input of the 555 if necessary.
    Attached is a revised asc file for a circuit which I think should meet your needs.
     

    Attached Files:

  17. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
    I havent checked your new sim but i wired everything up as id shown in my last post, removing the trigger resistor and such. wired the fet and relay and tuned the pot to 90k and its working with the solenoid perfectly.
    70k is where i start to get into problems.

    Last night while i was bored of waiting for the fet i wired only the relay to the solenoid, no ne555 or anything else.
    I knew this would keep the solenoid engaged but i just wanted to test out the relays really. They have an led indicator which helps.

    While i was testing i found that the relay had some kind of interference with the guns optic. Rapid firing seemed to throw the target off screen.
    Maybe something was playing around with the +5 feed i am getting off the optic.

    But during my tests tonight everything has run perfectly. Do you think keeping the fet is a good idea to keep the interference away?
     
    Last edited: Jun 6, 2013
  18. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
    I know this doesn't simulate properly but its the most accurate way for me to show you what Ive done.

    [​IMG]


    Thanks again for your help alec, when ive got some good lighting ill show you what youve helped me create.
    This will help alot of arcade and gaming guys out there.
     

    Attached Files:

    Last edited: Jun 6, 2013
  19. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
     
    Last edited by a moderator: Sep 10, 2013
  20. alec_t

    alec_t Well-Known Member Most Helpful Member

    Joined:
    Jul 10, 2011
    Messages:
    9,315
    Likes:
    1,230
    Location:
    Cardiff, Wales
    If you're determined to use a relay then you must have a reverse-biased diode connected across the relay coil (the same way as D1 is connected across the solenoid coil) to prevent damage to the FET, and spurious effects, caused by the back-emf generated by the relay coil inductance when the relay switches off.
     
  21. syntax_x

    syntax_x Member

    Joined:
    May 21, 2013
    Messages:
    39
    Likes:
    0
    Location:
    Australia
    ok ive added the diode, cheers.
    Im making another one today without the fet, if its not needed then its just added delay.

    should i wire it up like this?

    [​IMG]
     

Share This Page