Using a doorbell circuit to control things. Radio control

Discussion in 'The Projects Forum' started by Pusle, Nov 3, 2011.

  1. Pusle

    Thread Starter New Member

    Dec 23, 2009
    15
    2
    Hello boiz

    I have a doorbell circuit yea, im only interested in the wireless control part of it.

    How can i modify it to click and latch a relay when i press the button from any ware in the house. Also if it is somehow possible unlatch the relay when pressed again. Im sure you know what i mean.

    I was looking at it, all i think i have to do is create some sort of maybe, flip flip circuit (if i understand what they actually are correctly) so it will take the first signal, and send it to the relay, which will latch somehow. then it waits for a second signal, that it will just cut the power to the relay, or unlatch it.

    Also, i thought about using a MOSFET as a switch, as it will conserve battery power that will be taken from energizing a relay coil for however long the circuit is active.

    Thanks boiz.
     
  2. debjit625

    Well-Known Member

    Apr 17, 2010
    790
    186
    Post the schematic, if it’s wireless and it works then I think it will be not very difficult to activate a relay or turn on a MOSFET using that circuit.

    You got 5 posts bro...

    Good luck
     
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  3. Pusle

    Thread Starter New Member

    Dec 23, 2009
    15
    2
    sorry cuz, i dont have a circuit schematic, and i cant make one, because its all SMD devices, and super compact....

    But i can say that, when the wireless button is pressed, there is a constant 3V at the output wire for 8 seconds, then it goes to 0

    can 3V turn on a MOSFET? but i need some sort of latching circuit that will latch the relay or MOSFET when the button is pressed, and unlatch when it is pressed again

    Thanks bro
     
    Last edited: Nov 3, 2011
  4. Wendy

    Moderator

    Mar 24, 2008
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    The receiver is the hard part. I would look to something like a cheap radio, either AM or FM, then build a really simple transmitter. You would probably need to add a tone to give some circuitry to detect.

    As far as on/off goes, a simple 555 circuit would work.

    555 Bistable Multivibrator

    This could drive a logic level (or if the power supply is 12V) a regular MOSFET.

    The part that needs designing is the tone detector and relay.

    Rereading you post I suspect you are working with an existing design, I was thinking of starting from scratch.
     
  5. Pusle

    Thread Starter New Member

    Dec 23, 2009
    15
    2
    but why do i need to rebuild a circuit?

    this doorbell circuit's wireless receiver system all works. it transmits and receives. I just need to find out how to take a signal from 2 wires, and make it latch and unlatch a relay or MOSFET.

    - One press, latches, another press unlatches. it is pretty much just a wireless pushbutton
     
  6. t06afre

    AAC Fanatic!

    May 11, 2009
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    It is doable and not very hard. But how skilled with electronics are you. Have you build something on bread board or stripeboard before. And do you have some place that you can get hold on electronics parts
     
  7. Pusle

    Thread Starter New Member

    Dec 23, 2009
    15
    2
    t06afre, lol yes bro for sure

    i have my cousin to help, he has all the electronics and does the soldering. He does programming now, so yea thats no prob at all.

    i should be able to do it maybe lol, but it should only be like a couple of transistors with other basic components, true cuz?
     
  8. t06afre

    AAC Fanatic!

    May 11, 2009
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  9. Pusle

    Thread Starter New Member

    Dec 23, 2009
    15
    2
    t06afre, thankz cuz

    exactly what i need.

    No need for simplification, i could do that. I dont get all the new boiz they see an IC and say wallaahh i cant do that bro.

    Easy, only thing is i havent made my own printed circuits for about a year, i jus used project board. but yo ill assemble it on a breadboard, see is the dog works, and ill print it and use

    Also, will the 3v my doorbell applies for 8 seconds be enough for this circuit to work? i see there is an optocoupler, if thats wat the doorbell connects to it will work, cause this boy lights an LED easy

    Thanks Bro
     
  10. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    It won't work for you as-is.
    The input (from 3 to 5) is expecting either an open circuit, or a short to ground.
    You seem to have two fixed voltage levels for an output from your circuit.

    You will probably need to use an NPN transistor as an emitter follower to supply current to the IR emitter, instead of sinking current from the IR emitter. If you tried using a common emitter configuration, the logic would be inverted and the output would toggle states when the 8 second count expired, not immediately when you pressed the remote button.
     
  11. Pusle

    Thread Starter New Member

    Dec 23, 2009
    15
    2
    I dont understand what any of that means, but if i can get an LED to work, couldnt i connect an LED, and put it infront of a photoresistor as a switch.

    or, could i use that 3v to power some transistor, which will allow a MOSFET to turn on, and use the MOSFET's drain as the short to ground which will activate this circuit. Then exact same will happen to turn it off?
     
  12. Wendy

    Moderator

    Mar 24, 2008
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    I'm not sure whether you are aware of this or not, not really knowing your experience level, but an LED must have a current limiting resistor. I cover LED basics in Chapter 1 and the first half of chapter 2 of my article. It also has to have a power supply voltage greater than its voltage drop (Vf).

    I originally started this article about LEDs, the rest kinda just grew as I kept typing.

    LEDs, 555s, Flashers, and Light Chasers

    Many people try to treat LEDs as simple light bulbs, which obviously they are not. People using them have to pick up the beginnings of electronics, such as Ohm's Law, to use them proficiently. After you learn it you wind up wondering why it seemed hard at first.

    You should be able to modify your signature now. Use the power wisely.
     
  13. Pusle

    Thread Starter New Member

    Dec 23, 2009
    15
    2
    yeah its cool bro i know bout that, but it works out fine luckily as it is.
     
    Last edited: Nov 4, 2011
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