DIY Hacks & How To's: Phone Intercom

[@BrandonFrancey]

I did this years ago when I was in college. My buddies room was upstairs and mine was down stairs. When we did some LAN gaming it was a pain in the ass running up and down stairs getting things set up so I made this. What I did was I added a LED to the circuit on each end so when he picked up the phone, the LED would light up on my end and vice versa. What I found was that while I would always notice the LED and pick up, he rarely ever would notice. It was like he was studying or something. So I added a momentary push button on my end and a piezoelectric buzzer on his. I think I ran cat5 between the to jacks so I had extra pairs to work with but it all ran off of the 9 volt battery.

[@lachlanblack2469]

Hi Brandon Francey I was just wondering where on the circuit you added the LEDs - Your idea sounds interesting. Thanks

[@AbhishekRaj-hb4nu]

How to add led light and the buzzer. Will u please tell me about this

[@Abdulisbasith]

Dude , would love to know how you configured the led in it. Thanks :)

[@daanslager6815]

Could you tell us where on the circuit you added the led lights?

[@BrandonFrancey]

Sorry guys. I never received a single notification until today for some reason but I'll tell you exactly what I did. I picked up 2 external phone jack boxes. They are little plastic cheap boxes you plug your phone into. I ran CAT5 cable (4 pairs) between them because it's what I had but CAT 3 (2 pairs) would work too. In each box I drilled a hole and added an LED light. Then wiring isn't too hard once you understand it. For reference CAT 3 wire pairs are Red Green, and Black Yellow. The thing to keep in mind is we are making a simple circuit. With 1 phone in the first jack box we would go, battery + -> resistor -> red wire - >phone -> green -> battery - The circuit is completed when we pick up the receiver or push talk on a cordless phone. We could slip in an LED anywhere in this circuit and it would light up when we pick up the receiver but all that tells us is when we pick up the phone, and we already know that. To add a second phone we add the CAT 3 cable and connect the red wire to the same place as above to the resistor which goes to the second box. When a phone is connected to the second box, power comes back on the green that goes to battery -. If I add an LED here, it will tell me when the second phone is picked up. To tell when the first phone is picked up at the second location, I need to send power back up to it so on the first phone, instead of connecting the green line to negative, I connect it to black wire which goes to the second box, add an LED there between the black and yellow, and power comes back down yellow wire to finally get connected to battery - When I added the buzzer, I was using CAT 5 so I had 2 unused pairs. I just used one to make a simple circuit of battery + -> momentary switch -> buzzer -> battery - Button was on my side, buzzer on his.

[@persebra]

normally one would not need it these days with all the cell phones. but since its recycling something, and its just about free, this is a great idea. and a big finger to the NSA

[@jayfulf]

You can actually do this with cordless as well which allows you to have the bases very close together and the handsets wherever you want.

[@MrMattperreault]

Fantastic project! I'm going to try this with my students! Someone should post the instructions mentioned below for making it ring!

[@lunhil1264]

I remember electricians doing wire runs had made battery powered handsets with alligator clips on them. They used the buildings wiring to communicate with each other through this system.

[@grodenbarg]

done it. BTW: if you want to make a phone ring, you need to SAFELY pump about 90-120 volts AC through the line. LOL

[@dinbee4611]

How do you make the other phone ring when calling that unit? Kinda missed it in the video. Some comments here said you gotta add 90-120v to it? How?

[@KitMacAllister]

This hack also works with Wireless phones. You will need to supply power for the phones, but the line will still work without plugging it into a phone jack.

[@FNGFASHA]

Thanks for the video. Question. If I follow you video and put one phone in my house and the other in my shop, how can I make the one in the shop ring when my wife wants to talk to me from the one in house?

[@kiri2235]

You could do this with a Dual cordless phone set such as a BT trio/duo pack, no landline needed.

[@richkawaiipikachu]

Neat project, just would be nicer if theres a way to make the phones ring ethar via a.) picking up the handset to make the other end ring or b.) pressing a dial button to make it ring

[@GabrielleRevlock1]

Has anyone figured out how to do that?

[@MechInvent]

Dude you rock!! This was exactly what I was looking for.

[@themeantuber]

I used to do exactly this when I was a kid (minus the resistor, since the phones are able to handle much higher voltage than that of a battery.) The only problem with this setting is knowing when to pick up the phone, since it doesn't ring. Sometimes the pulse dialer may be able to create chirping on the other end, when the other phone is on hook. But it depends on the telephones you use.

[@homemadeyumies9097]

Can you make a video for multiple phones and to add a speaker

[@warnematt]

holy shit, a project made without a microcontroller! resubbed.

[@shazizz]

Cool idea, now you need a ringer so the person at the other in knows to pick up the phone! Like an obnoxiously loud air horn!

[@PrimalEdge]

LOL, exactly what I was thinking!

[@elixeroflife]

just do a web search on how to build a Frequency Shift Key Modem. you can even program numeric designations into it and have phones all over the house with your own private phone network.

[@austins_creations]

you could hack into button on the phone or add one, add an extra few wires to the cord (or us an ethernet cable and swap the jack for the phone jack and use the extra wires in the cable to add an extra connector to wire up a switch. and a buzzer, then on the other end set it up so that the switch on one phone taps into the buzzer and vise versa. if you wanted multiple phones and wanted to select who gets the buzz you could add a selector switch to the phone. (or use the dial pad and each button could be for a different phone.

[@austins_creations]

phone intercom | austinscreations3000 this might help. (my personal website)

[@austins_creations]

thanks.

[@okamijubei]

That's neat but what if you want to hook up more than two phones for intercoms?

[@canairsoftregiment]

this was really a cool idea :D but what would be amazingly cool would be to be able to connect multiple phones, or rather, make a multi line type intercom so separate phones could have separate lines

[@kathrynmullins2640]

Or just use walkie talkies. Then you're not fixed into set positions, should you have to move.

[@electronicsNmore]

Very Good Idea.

[@amberschlegel9326]

can you make one that has 8 phones and a buzzer for the phones and a zoneing system for them

[@kaosthecosmicreviewer1055]

could you solder a momentary switch to the 9v battery, and then from the switch to a small piezo speaker, pressing it would make the piezo sound and alert someone that you are trying to call them? Also, could you install a headset and mic into this, if so how?

[@ethanroland59]

Is there a way to connect 3 or more phones? Very important so if someone can help please!!

[@sk8emilio00]

I'm thinking making a two way switch with led/ringer next to it

[@vpleric]

Is there a how to video to add a ringer or led to these phones?

[@AndrejSpilevoj]

Any idea how to make the phone ring so person on the other side of the line knows when to pick up?

[@NemuiJin]

This is awesome. I wonder how long of a phone line this works with. Would've been a cool thing for neighborhood kids to talk to each other back before cell phones. We were always getting yelled at for tying up the phone line.

[@RobertBeck-pp2ru]

You need to safely impose 120 volts AC into the low voltage DC system you just built. Use a momentary push button rated for 120 volts to make the phones ring. ( They will both ring together when the button is pressed. )

[@oakeydokey2]

If I modified this project, used 8 phones and a 36 volt power supply, what resistor would i need?

[@sethhorst6158]

One of the public buildings in the City My Family lives in has something like that. There's a box on the outside of the building on the wall that says phone, when you open it, there's a telephone in it. When you pick up the receiver, an employee of the building will answer. I experienced one by mistaking one as a public pay phone.

[@video48s]

Great video. Do you think this can work in an old pulse phone?

[@Quiroztube]

it should work too!!

[@Bills724]

When you pick up one phone does the other ring ?

[@lumiredes123]

Great, any ideas for a ringing sistem

[@kophein]

on very old phones, you just need to push the receiver switch a few times on any of the phones, and the other one will start making noises...

[@itzryland]

I did exactly everything he did but I used a 330 ohm resistor and a 12v adapter it works but I can't get voice to work nor dmtf tones. If anyone knows the solution please help me ASAP.

[@ryanamberger]

Is it possible to add another line in with it wired into an led glued to each phone thatll light up when one handset is picked up?

[@nathanalaneller]

Can U make the phone ring to get the other callers attention?

[@Quiroztube]

Can you tell me why you are using a resistor? What is its function in the circuit?

[@AtomIntention]

Could you possibly tell me the basic steps to just simply power a phone with a 9v? I just want the sounds, seems like it would be just like this video but even easier, I’m definitely a beginner at this stuff Thank you!

[@SuperSparr01]

Or just buy a Viking Electronics DLE-200B. That way you can get ringing on both ends. Then you know when someone is calling you. 9VD is very low talk battery. Any hands free phone will require more voltage and loop current.

[@scottconner5401]

What about make it a school intercom that is basclily just a landline not a. Intercom intercom is when you speak into a mic and add a speaker into a ceiling and connect the mic to the intercom

[@Alpha-Alpha]

I know this sound stupid... but why do we need the resistor? what is its function? It will be great if someone can briefly explain it... thanks :)

[@zaidhussain5206]

Thank you so much for this project

[@yamspaine]

I need a ringer. I bought an old crank from a really old style phone... it provides AC power sufficient to ring a phone... but I need to figure out how it disconnects the battery or not...

[@SirMilad]

I am looking for a simple door phone with a normal sound not loud like video door phones. What do you suggest?

[@nathunder1]

I've done this project before with great success, but with the 9vdc that you mention at the end, but on my current project I am getting so much "static" or "buzz" that I can't hear anything else; what am I forgetting. Is this why I need the resister (which I didn't use)? Thanks.

[@turbojurpo]

That is why you need a resistor

[@nathunder1]

@@turbojurpo , wow I guess better late than never.LOL. Thanks for the input. I have installed this project (using a 9VDC converter at several location.); it has been a huge help.

[@support12-b2t]

Can u do this with out the resistor

[@random_tek]

No. Resistor is required, or else it would fry the phones

[@79sketches]

Ok, now I know it can be done. Now... I want to do this to create an intercom between my helmet and my passenger helmet for log motorcycle trips. How Can I miniaturize or minimize the components?

[@mihaim3587]

Can you link two small wireless phones with the same cord trick ? I hope you understand my question.

[@louiesrego]

if I have a phone line then I use a splitter, is it possible to call to the other phone?

[@nickkilcoyne8265]

Any way to make the phone ring?

[@AREA_FIFTY_1]

is it permanently live or will it ring the other side of the line until its picked up? Cheers mate'

[@dipulator]

anybody have info on how to add a ring option to this so you can signal for someone to pick up the other end>?

[@mistersync100]

nice and simple

[@technicalsupport6573]

How can i do same connection for 3 way intercom. I want to connect 3 telephone in the house instead of 2

[@sayrith]

Its cool. I did something like this when I was a kid. But how do you let the other person know you want to talk to them? You need to be able to make the phone ring.

[@ThoolooExpress]

60+V, 20Hz, and you're in business.

[@Waadee101]

The volume on these is very how. Any idea how to increase the volume ?

[@AlanAlanAlanDave]

How do you know when some one is calling? and what distance can this reach?

[@biesasuk]

Would be amazing if anyone could put a video on how to set up intercom phone in your apartment, so that the person downstairs when presses the button at the front door, doors would open automatically without manually lifting the phone and pressing #9. Could never ever find one!

[@or2169]

What is the maximum length in wire you can use? Also can you make a junk yard circuit? You know multiple phones on that one circuit?

[@SuperSparr01]

Not many since your talk battery will be so low.

[@yaytfan]

Very useful, nice job. Just one question: why we need a resistor? Thanks.

[@Prime96]

Queria saber tambem

[@LarsTechTipsDe]

The phone cable has multiple wires inside and it look like you only need 2 for the phone, so you can use the other wires to connect a door bell by each phone. For that 3 wires would be enough as well. 1 Ground and the other one for the switches.

[@ThoolooExpress]

Not to be captain obvious, but don't phones already have ringers? All it needs is 60+V and 20+Hz to activate.

[@LarsTechTipsDe]

ThoolooExpress I guess that would be possible, but there is some sort of circuitry in the phone, that I have no clue of :D

[@ThoolooExpress]

Lars Reviews There's a capacitor that prevents DC from flowing to the ringer, so the ringer doesn't complete the circuit on the 9V. (If this happened, the exchange would think you picked up the phone.) The problem is that phones have no capability to produce the necessary signal to activate the ringer, as it is normally handled by the switches at the exchange. You'd need to create an external power supply that could be activated by either pressing a button on the keypad, or get cranky with a magneto.

[@LarsTechTipsDe]

ThoolooExpress That is why I would use a doorbell :D

[@cameramandanno]

How do you make it ring to alert for pick up ??

[@Jbrese58]

Pretty Slick. Thanks!!!!

[@rudraswamy.c.tswamy822]

Hai , I am from India and saw video BT78A Impressed but have a beetel m78 landline 1+1 and i have a challenge that in my shop want to use this without any external connection provider like (BSNL,MTNL,Airtel or etc..) how can i connect only for intercom....do you have any device....

[@johngilmour8945]

I need Advice? my building intercom does not function without a landline connection? would it be possible to modify the intercom to not having to use a landline phone? as we do not use our phone for communication (Calling Friends Or receiving calls? we would prefer a single standing intercom system without having to use a bell, or rogers supplied telephone line?

[@random_tek]

Landline is required. You can't do anything about it

[@AikoukaOokami]

i did a vid on this about 2 years ago phone jack intercom

[@callumj.p.r1714]

Hi. Would it be possible to do this with more than two phones? and if so could you explain how. Thanks

[@callumj.p.r1714]

And also if possible to add a ringer

[@gamingit1]

Can i use 12v dc adapter?

[@darrylm1333]

Will the phones ring?

[@nathanscott1975]

What is the resister needed for?

[@gabriellelapalme1417]

Hi there! How would it work with the telephone cable that have 4 ends?

[@random_tek]

Yes, it would work, but you have to be very careful and figure out which wire to connect

[@ke0wpc]

I got it to work with a more common 470ohm resistor

[@LaneB217]

how do i change this to work with two 3.5mm jack headsets?

[@random_tek]

You can watch one of electroboom's video

[@GRAVESAUDIO]

I made this but am getting a loud feed back out of my speakers? any help would be great

[@Themysterymove]

How do you activate the ringer?

[@lachlanblack2469]

Hi, I am going to do this project in my room however I was just wandering what type of telephone wire do I need like a 2 wire or 4? And where do I attach the LED's to the circuit? Thanks

[@lachlanblack2469]

Make: ^^^^^

[@chrispulley94]

Lachlan Black two wire u can get a cheap phones at walmart

[@Danjls-Long]

Does it only work with analog phones

[@random_tek]

you can also use cordless phones, fax machines etc.

[@sidgurjar]

Can you tell how to convert a wired intercom into a wireless one?

[@fourwindbadger8066]

How to get it to go ring ring?

[@mariandeacu]

What is the distance at which they can communicate ?

[@harabisj]

Endless

[@LarsSveen]

Long enough for any house. You might run into issues over a thousand feet or something. That's not a hard figure, I just mean at some really long length the power will attenuate to the point that you won't be able to hear the other person. There are calculations to figure out voltage drop.

[@RainbowCorpses]

I need halp my phone wire has 4 wires, i got confused n cut them all. I got a spare cord though, there's no sound heard what did i do wrong, how have i failed in this simple task.

[@escapetoparadise2226]

Can u make it ring?

[@kavindugilshan]

Which value of resistor suitable for 12V supply ??

[@ulises5369]

Kavindu Gilshan 600 oms

[@MrJamesbowen]

The best intercom phone hack i've seen is to use a 2 port ATA device (cheap off eBay) and have the loopback to itself on the alternate line. Add a dial plan which makes a call a soon a the phone is off-hook and it will ring the other line and vice-a-versa. pap2t-ringdown-test

[@drincogni]

I found an easier method, i scream.Both people scream. I live on an island .

[@jlastname6133]

So if one were to to paint the phones in a black with a matte finish, could they be called "bat phones"? Actually.. as I started to type I remembered that the bat phone in the commissioner's office was actually red and quite lumpy-looking. Wasn't it kept under one of those pie covers you see in every old-timey diners? What was the deal with that? Security? Aesthetics?

[@TheRacingEarPodcast]

Is the 300 ohm resistor a 1/4 watt at 5%?? Just to be clear, it isn't a 300K ohm resistor right? Is it the same as a 1K ohm resistor?

[@nextstorming3908]

He said ohm NOT K-ohm

[@LarsSveen]

1k = 1000 =/= 300. FYI, pretty much anything under 300 ohms should be fine.

[@bassing1019]

How long can the cord be

[@michalnemecek3575]

Can it run on USB?

[@katykab00m]

Sooooo cool!!

[@ZBvids]

Why do you need the resister?

[@random_tek]

Did you skip physics class?

[@christophertaylor87]

But how will the other person know when to pick up the phone? Will it ring?

[@mayaahoki]

is there any possible way i could connect 3 phones to that intercom system

[@johnsmith-qn2gd]

yes, but it would get a little more complicated

[@gwapojudkoalangan]

can you do it with a headset? that would be really cool

[@mineciberkay]

Is it dialing?

[@bluetorch13]

I want to make this but with a speaker on the other end, like an intercom! relay so when I pick up, it turns on, and an amp for the speaker.

[@creeperzone2215]

replace the siny speaker on the phone with an amp, connected to a speaker.

[@coachgeo]

what is purpose of resister?? .... lot of folk have done this w/out resister.

[@crazyjoeshorts5256]

From what I've heard, it cuts down on noise. Without it, the line has a lot of static. Maybe they had some natural resistance built in due to using a poor conductor wire or lower actual voltage. I really want to try this.

[@trezythirdy3527]

I don't know how to solder. What do I do?

[@guedosha]

does it matter which wire the stuff is connected to

[@random_tek]

Yes, it does actually matter

[@dablet]

anyone got it working with 10 phones in 10 rooms?

[@mongkydanchiko8235]

Good videos

[@joedebosco3047]

Here is an issue: You do not explain how to "ring" the other phone!! Sure it works if both parties are aware they need to talk and pick up the phones in unison. But ---what if I need to call the other line?