Questions tagged [telephone]
A telephone, is a telecommunications device that converts sound into electronic signals suitable for transmission via cables
18
questions with no upvoted or accepted answers
3
votes
0
answers
752
views
Connect speaker directly to Samsung Galaxy S6. Minimum impedance accepted
I want to connect an external (passive) speaker (3W/16 ohm) directly to my Samsung Galaxy S6 using the headphone jack. I want to do this on my bicycle using the smallest space possible. Connecting the ...
- 834
1
vote
0
answers
192
views
Why are old RJ-11 modular telephone cables reversed?
I've checked all my old modular phone cables and all of them have the terminal plugs attached so that the wiring is reversed. That is plug 1 is Black-Red-Green-Yellow and at the other end of the ...
- 709
1
vote
0
answers
397
views
Connecting 4P4C RJ9 Headset to 3.5mm pc port
I have a Plantronics CS520 Binaural headset that I'm trying to connect to my PC instead of a desk phone.
I'm using a TRRS with T connected to speaker+, R disconnected, R connected to Mic, and S being ...
- 19
1
vote
0
answers
65
views
Leaky Bucket Example
I have an image below of a leaky bucket image that I am trying to understand for my telecommunications class, and I was hoping for some guidance/verification if my train of thought is on the right ...
- 187
1
vote
0
answers
483
views
Are the two wires in a telephone cable swappable?
I am in Switzerland.
Our landline is delivered through an unshielded twisted pair cable.
Are the wires in the pair swappable ? Or does it have a polarity ?
The lines is supposed to provide ADSL ...
- 6,651
1
vote
0
answers
400
views
Is it technologically possible for IVR systems to recognize and support pulse dialing
I understand all the concepts behind IVR systems.
I've never been able to quite understand why pulse dialing can't be used with IVR systems. Tones are obviously sent to the other party, but a pulse ...
- 373
1
vote
0
answers
359
views
hijack project microtransformer doesn't work well
I am working on a project that need to get energy harvest from smartphone headset jack.I find hijack project has a solution.the energy harvest circuit of it is below:
it use coilcraft transformer ...
- 11
1
vote
1
answer
127
views
Getting two way audio from/to a landline telephone, and making it ring
I have a "land line" telephone (ie. with an RJ11 plug) and a CSR8615 HFP bluetooth module (datasheet) — I'm looking to make my mobile's phone calls ring the land line phone, as well as being able to ...
- 624
0
votes
0
answers
110
views
How to connect a Battery Charging board / Management system, directly to a phones PCB to provide an alternative port for charging?
I have a Welcome phone (a no name phone) where I'm hoping to use the standard phone charging port for other uses. So I thought that I could solider a Battery Management system (BMS) directly to the ...
0
votes
1
answer
180
views
Intercom from old corded telephones
I'm experimenting with making a simple intercom from two old corded telephones.
I'm including a buzzer and momentary switch on each end for an incoming call alert.
Below is the circuit I made using ...
- 709
0
votes
1
answer
118
views
Solar lamp/phone charger output current too low for modern phones
I am building a solar lamp/phone charger following this page, with the circuit here below.
I have two 18650 batteries in parallel. The charger module is the usual TP4056 taking 5 V input, and limited ...
- 1
0
votes
0
answers
92
views
Telephone headset adaptor weak microphone and speaker sound
I have made a simple adaptor for a telephone P4C4 -- RJ9 -- separate headset output (The wiring diagram of a telephone handset can be viewed in this wikipedia article) to two TRS jack for an ordinary ...
- 11
0
votes
0
answers
60
views
Two phone batteries connected in series not working
I have two, fully charged, 3.7V standard Nokia phone batteries, that I want to connect together to use as a 7.4V battery, I connected the (+) of one to the (-) of the other, and then tested it but it ...
- 101
0
votes
0
answers
93
views
About live telephone line voltage
I have a question about the telephone line voltage.
When I make a short for 12 volt I see the spark and heating, my question is why I can’t see anything (spark, heating) when I make short with the ...
- 1
0
votes
0
answers
123
views
How could landline telephone service cause fire alarms to activate?
Someone I know informed me that their home’s fire alarm is occasionally triggered when he uses his home phone (landline). His alarm system company stated that they do not know why this occurs. They ...
- 101
0
votes
1
answer
56
views
How does a video entry system send audio and video, as well as ring/unlock over 4 wires?
I’ve been trying to understand how my door entry system works.
Between the monitor/base station and the bell/camera/speaker there’s only 4 wires:
12V DC
GND
Voice (2 way)
Video (1 way)
I opened it ...
- 145
0
votes
1
answer
61
views
3x AA battery phone charger input voltage drop
I am using a 0.9-5 V to 5 V dc-dc step up converter to charge a phone using 3 AA batteries, but whenever I plug in the phone it starts charging but the input voltage drops from ~4.5 V to less than 2 V ...
- 3
0
votes
1
answer
69
views
DC power filter curicut
I have a problem in powering my wireless Panasonic landline telephone. It works on 9v power with a transformer that work on 220v and gives as output 9v and it works fine with this way. I try to power ...
- 11