Phone Busy Indicator

phone busy indicator


Have you ever been using the modem or fax and someone else picks up the phone, breaking the connection? Well, this simple circuit should put an end to that. It signals that the phone is in use by lighting a red LED. When the phone is not in use, a green LED is lit. It needs no external power and can be connected anywhere on the phone line, even mounted inside the phone.

Phone Busy Indicator circuit

PARTS LIST
R1 3.3KΩ 1/4 W
R2 33KΩ 1/4 W
R3 56KΩ 1/4 W
R4 22KΩ 1/4 W
R5 4.7KΩ 1/4 W
Q1 2N3392 NPN Transistor
Q2 2N3392 NPN Transistor
BR1 1.5 Amp 250 PIV Bridge Rectifier
D1 Red LED
D2 Green LED
MISC Wire, Case, Phone Cord

Notes:

1. This is a very simple circuit and is easily made on a perf board and mounted inside the phone.
2. LED1 and LED2 flash on and off while the phone is ringing.
3. Do not worry about mixing up the Tip and Ring connections.
4. The ring voltage on a phone line is anywhere from 90 to 130 volts. Make sure no one calls while you are making the line connections or you’ll know it.
5. In some countries or states you will have to ask the phone company before you connect this to the line. It might even require an inspection.
6. If the circuit causes distortion on the phone line, connect a 680 ohm resistor in between one of the incoming line wires and the bridge rectifier.

Please send your ideas, those are very important for our success…

Tags:
0 comments on “Phone Busy Indicator
  1. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Info very well taken..

    men and ther comments on viagra free trial pack of viagra
    viagra without a doctors prescription
    jimmy kimel viagra for women video – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  2. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Good posts. Thank you!

    mdma viagra generic viagra and india
    buy generic viagra
    cialis online compare discount viagra – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  3. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Regards, Useful stuff.

    femail effects viagra viagra effect on heart
    cheap viagra
    where to buy viagra safe – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  4. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Factor well taken!!

    viagra nitrite cipla viagra
    generic viagra online
    advice about buying generic viagra online – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  5. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    With thanks! Lots of knowledge.

    viagra doctors houston how much is viagra at cvs
    viagra generic
    most recognized brand viagra – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  6. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Fantastic knowledge. Regards.

    viagra usage reviews does viagra result in longer erections
    cheap viagra
    free sites results computer viagra – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  7. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Perfectly voiced of course! !

    plant viagra flower viagra kitchen commercial
    viagra for women
    drugs like viagra – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  8. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Nicely put. Cheers!

    herbal viagra that works buy viagra pills cheer
    viagra for sale uk
    driving on viagra – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  9. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Wow tons of valuable information!

    psa and viagra how often can someone take viagra
    buy generic viagra
    viagra cursor – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  10. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Nicely spoken really. !

    generics mexico viagra femail viagra
    generic viagra 100mg
    buy viagra online – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  11. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Cheers. I enjoy it.

    generic viagra cost viagra latest side effects
    buy viagra
    viagra blue vision – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  12. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Tips certainly utilized.!

    female liquid viagra viagra online online a href
    viagra without a doctors prescription
    by viagra in uk – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  13. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You mentioned that exceptionally well!

    viagra treats teenren s lethal hypertension plant viagra flower
    viagra online
    side effects from viagra – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  14. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Cheers! Plenty of stuff.

    finding viagra in the philippines women consume viagra
    viagra without a doctor prescription
    viagra k pes – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  15. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    This is nicely put! !

    viagra liver effexor and viagra
    generic viagra 100mg
    generic viagra 3a caverta cialis cheap – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  16. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Nicely put, Regards!

    viagra cialis and relationships harvard study viagra advice for consuming 2 tablets
    viagra for women
    when viagra does not work – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  17. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You expressed this adequately!

    buy overseas viagra viagra buy australia
    viagra 100mg
    viagra absorption problem – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  18. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Kudos! An abundance of write ups!

    india pharmacies generic viagra online viagra order
    generic viagra
    marketing ideas for viagra – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  19. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Wonderful write ups, Thank you.

    viagra daily use viagra in peru
    generic viagra 100mg
    cheapest viagra substitute sildenafil – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  20. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You’ve made your point quite nicely!!

    2 free viagra shop and compare charles linskaill viagra
    viagra pills
    viagra hom eoffice toronto – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  21. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Thanks a lot. I value this!

    next day shipping on viagra moon flowers viagra
    generic viagra
    ringtone viva viagra – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  22. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Cheers, I value this!

    viagra photophobia viagra to combat propecia
    generic viagra 100mg
    viagra from china – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  23. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    With thanks! I enjoy it!

    female viagra europe viagra high school college males
    generic viagra online
    viagra message boards – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  24. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Very well spoken really! !

    herbal viagra in stores viagra pharmacy
    viagra for women
    viagra add men singing – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  25. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Thanks, Awesome information.

    cheapest viagra anywhere viagra quotations
    viagra generic
    make viagra – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  26. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You explained that superbly.

    viagra side efects viagra and parkinsons
    generic viagra 100mg
    search viagra viagra find 74k generic – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  27. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You revealed this perfectly!

    viagra find sites free viagra slutload
    viagra online
    ways to givr viagra – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  28. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Cheers, A good amount of stuff.

    viagra cock sertraline viagra
    buy viagra
    viagra addictive – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  29. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Many thanks. An abundance of information!

    buy online viagra where viagra in the news
    generic viagra 100mg
    medicaid coverage viagra – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  30. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Nicely put, With thanks!

    buy viagra online online a href how many hours for viagra
    viagra for sale uk
    viagra purchase online – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  31. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Truly quite a lot of beneficial information!

    aspirin vs viagra viagra or cilas
    buy generic viagra
    russia status of viagra – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  32. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You expressed it perfectly!

    free trial viagra levitra onde comprar a viagra no brasil
    buy viagra online
    viagra ill effects – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  33. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Excellent information. With thanks!

    cialis viagra viagra what do you use after viagra
    viagra without a doctors prescription
    viagra type of medicines – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  34. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Truly a lot of helpful data.

    viagra sale free generic where to buy viagra in bangkok
    viagra for sale uk
    discovery of viagra – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  35. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You have made your stand pretty nicely.!

    email viagra virus solution mushrooms and viagra
    viagra online
    viagra and mastrubation – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  36. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Regards, I enjoy this!

    priscilla presley and viva viagra find viagra edinburgh search pages
    viagra for sale uk
    natural supplement viagra – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  37. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Appreciate it! Numerous forum posts.

    bought viagra fuerteventura viagra marketing personalities
    viagra without a doctors prescription
    viagra order online – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  38. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Nicely put. Kudos.

    cheapest viagra super active pills thc female viagra
    viagra online
    buy online pill viagra – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  39. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Helpful content. Thank you.

    what ingredients are in viagra viagra video commercial
    generic viagra
    viagra news edinburgh cfm moo tid – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  40. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You have made your point pretty nicely..

    where to buy viagra on line rinoceronte viagra
    generic viagra 100mg
    generaic viagra – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  41. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Nicely put, Appreciate it.

    different mg of viagra 90 for 135 viagra
    cheap viagra
    viagra kitchen commercial – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  42. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Position certainly considered!!

    what pharmacys sell viagra reversing the effects of viagra
    buy generic viagra
    viagra trial packs – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  43. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Whoa plenty of superb advice!

    holistic viagra viagra pro online in usa
    viagra 100mg
    watermelon viagra – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  44. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Kudos. Valuable information!

    herbal viagra tablets viagra prices united states
    buy viagra online
    viagra carvedilol interaction – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  45. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Thank you. Lots of postings.

    pfizer viagra and its cautions viagra ans cialis
    buy viagra
    edinburgh viagra mmr find search – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  46. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You mentioned this perfectly.

    viagra rx online louisville commercial viagra
    viagra generic
    herbal viagra walgreens – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  47. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Amazing material, Thanks.

    benefits of recreational viagra use viagra 3
    viagra without a doctors prescription
    viagra for momen – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  48. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Really many of good material!

    low blood pressure taking viagra viagra thailand
    generic viagra 100mg
    proven competitor to viagra cialis levitra – https://genericviagrarcp.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  49. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Thank you, I value this.

    online viagra pills edinburgh uk viagra search computer find
    viagra online
    zoloft and viagra – https://genericviagrantx.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  50. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    Regards, I enjoy this.

    coleman 2000 viagra last free viagra hotline
    viagra for women
    acheter du viagra – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

  51. Larryhog says:
    Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.

    You made your point.

    internet viagra legality of cum 3 times with viagra stories
    viagra 100mg
    does viagra help keep it up – https://genericviagramsl.com

    GeraldZiz
    Dwaynemom
    KevinOriep

Leave a Reply

Your email address will not be published. Required fields are marked *

*

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Electronic Circuits

LINKS

Enter your email address:

Electronics

Top