Connect with us

Help - timing and switching circuit needed

Discussion in 'Electronic Design' started by Steve Newport, Mar 28, 2007.

Scroll to continue with content
  1. Hello all,

    I am trying to find out how to build (sorry am a relative amature) a
    timing and switching circuit. The basics are as follows:

    Operates off a 12v dc battery
    operates (single pulse) up to eight 12v dc solenoids.
    sequence of operation is set
    timing between each operation could vary in the range 12-48 hours

    Can anybody help?
     
  2. chuck

    chuck Guest

    Check this out, Google on what you don't
    understand, and ask again if you need help.

    Good luck, Steve.

    Chuck

    http://uk.geocities.com/ronj_1217/c4060s.html
    Two Simple 24-Hour Timer Circuit Schematics
     
  3. ehsjr

    ehsjr Guest

    Do you mean that solenoid 1 operates, then 12-48 hours
    later solenoid 2 operates, then 12-48 hours later
    solenoid 3 operates, etc?

    Ed
     
  4. Yep, a couple of places in the sequence more than one solenoid may
    operate but essentialy yes.
     
  5. Donald

    Donald Guest

    Ok, a long duration sequencer.

    What is the "single pulse" ??

    Any microcontroller chip with a RTC (real time clock) chip and a relay
    driver chip can do this.

    Are you looking at "building this yourself" by,

    a) buying computer/logic boards and programming them yourself.
    b) building your computer/logic PCBs and soldering the chips down
    yourself then programming them.
    or
    c) buying a complete system that can control relays with a "single pulse"

    How much of "build it" are you interested in doing ??

    donald
     
  6. Sorry, the description I gave was a bit wooly. The solenoid acts to
    open a small catch - all it needs is one pulse to make it pull. ie: No
    need for a permanent current to be applied. Hope that makes sense.

    Was hoping to do a complete self build but if there is something ready
    made then why re0invent the wheel so to speak?

    Was hpong that what I need would be some combination of a 555 chip and
    relay etc. Wasn't imagining anything like programming as that would
    probably be quite beyon my capabilities.

    I could cope (just) with buying components and soldering them together
    :-(
     
  7. ehsjr

    ehsjr Guest

    There's a kit than can be set up to give you a pulse
    every ~22 hours (or less).
    http://store.qkits.com/moreinfo.cfm/QK152
    You would need to add two circuits: a 4017 counter to
    advance to the next solenoid when the kit provides a
    pulse, and a solenoid driver circuit that will provide
    a pulse to the solenoid. We need to know a couple of
    things. How long does the pulse to the solenoid have
    to be, at a minimum? How much current does the solenoid
    take? Can you build the two additional circuits without
    using a kit?

    Ed
     
  8. Thanks Ed. The solenoid I was looking to use can be seen at
    http://www.islikersolenoids.co.uk/scripts/isliker/linear_type5.html

    Not suggesting you look it up - just wanted to state it in case you
    wanted to look. I have downloaded the technical data sheet but it
    doesn't seem to give the details so I have emailed the company and
    asked. I'll post back when I get a reply.

    I understand what you have suggested (many thanks indeed) and it makes
    sense. Whilst I am probably OK with the solenoid driver circuit; the
    technical data sheet I downloaded gives me some examples and they seem
    straight forward. However, the 4017 counter - I wouldn't know where to
    start. Is it likely that a kit is available?
     
  9. ehsjr

    ehsjr Guest

    There is a kit CAT# AEC at Allelectronics
    http://www.allelectronics.com/

    It is an LED chaser kit - you would need to modify
    it (simple - don't install the 555). As designed, a
    555 runs as an astable. The output of the 555 clocks
    the 4017 counter - the output of the counter drives
    the LEDs. You would use the QK152 output to create
    the clock pulse that advances the 4017 counter.
    Connect teh QK152 output to pin 14 of the 4017.
    You would also need to modify the QK152 to reset
    itself when it reached the period you select so that
    it starts timing all over again. (Mod described
    below)

    Here's how you could do it:
    In the QK152 when the 4020 counter reaches a value of 8,
    use that pulse to activate the solenoid driver. When the
    count reaches the value equal to your period, use that
    pulse to advance the 4017. The same pulse is used to
    reset the 4020 to 0 (connect the reset pin, pin 11, to
    the pin for the period you chose). The 4017 count is used
    to energize a relay or bias a transistor on so that when
    the solenoid driver pulse arrives ~ 8 seconds later, the
    correct solenoid is fired.

    QK152 mod: you need to connect pin 4 of the 555 to
    pin 8 of the 555, and remove the connection from pin
    4 of the 555 to the collector of Q1. The collector
    of Q1 needs to remain connected to R7 if you wish
    to use the transistor outputs for something. As mentioned
    above, you need to connect the period output pin to
    tyhe reset pin to set the 4020 to 0.

    Ed
     
  10. ehsjr

    ehsjr Guest

    Aargh! There was an error in my reply. I have modified the
    reply, below, to correct the error. The good news is that it
    will simplify things, and save needing a solenoid driver.

    There is a kit CAT# AEC at Allelectronics
    http://www.allelectronics.com/

    It is an LED chaser kit - you would need to modify it
    (simple - don't install the 555). As designed, a 555
    runs as an astable. The output of the 555 clocks the
    CD4017 counter - the output of the counter drives the LEDs.
    You would use the QK152 8192 output (4020 pin 3) to create
    the clock pulse that advances the 4017 counter. Connect
    the QK152 4020 pin 3 to pin 14 of the 4017 in the AEC kit.

    Here's how you could do it:
    In the QK152 when the 4020 counter reaches a value of 8192,
    use that pulse to advance the 4017 in the AEC. The 4017 count
    is used to bias a transistor on so that when the solenoid
    driver relay pulse arrives ~ 8 miliseconds later, the correct
    solenoid is fired.

    AEC mod: omit 555 and LEDs. Remove existing connection to 4017
    pin 15 and connect count N+1 output pin to pin 15, where N is
    the number of solenoids. See the 4017 datasheet.

    QK152 mod: you need to connect pin 4 of the 555 to pin 8 of
    the 555, and remove the connection from pin 4 of the 555 to
    the collector of Q1. The collector of Q1 needs to remain
    connected to R7. Use the QK152 relay contact to connect + to
    the solenoid. Partial schematic below.


    QK152
    Relay contact
    +24 -----o---
    ^---o----+----+------+----+------+----+--}}----
    | | | | | |
    [Sol1] [D1] [Sol2] [D2] [Sol3] [D3]
    | |a | |a | |a
    +----+ +----+ +----+
    | | |
    /c | |
    4017 pin 3 --[R]--| NPN | |
    \e | |
    | | |
    Gnd | |
    /c |
    4017 pin 2 ---------[R]-------| NPN |
    \e |
    | |
    Gnd |
    /c
    4017 pin 4 ---------[R]-------------------| NPN
    \e
    |
    Gnd

    Note that it assumes 24V solenoids. The relay contacts
    in the QK152 can handle up to 10 amps. The transistors
    have to be chosen to handle the solenoid current and may
    need to be darlingtons or FETs. R should be at least 1K

    Ed
     

  11. Many thanks Ed, really appreciated. I will pull this together and have
    a go.
     
  12. jasen

    jasen Guest

    google for 555+monostable

    and 555+relay

    If you'd asked in s.e.b I'd have posted you a schematic.

    Bye.
    Jasen
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-