Is this possible to do?

SparkyCal

Mar 11, 2020
863
Joined
Mar 11, 2020
Messages
863
That's worth doing. Thank-you. I will have to see if I have one.

Is it possible to use some sort of tri-color LED that would shine a different color depending on how much voltage it receives?


P.S. I have a bunch of Diodes. How would I know if a diode is a Zener?
 

crutschow

May 7, 2021
984
Joined
May 7, 2021
Messages
984
s it possible to use some sort of tri-color LED that would shine a different color depending on how much voltage it receives?
Depends upon what connections are available to the tri-color LED.
Likely, using a Zener, you could get one to light dimly when off-hook and two to light simultaneously when on-hook.
I have a bunch of Diodes. How would I know if a diode is a Zener?
Look up its part number.
Otherwise, apply a voltage in series with a 10kΩ resistor in the reverse direction and see at what voltage it breaks down.
 
Last edited:

Externet

Aug 24, 2009
943
Joined
Aug 24, 2009
Messages
943
It would be better if it were the other way around, but it still works and is useful.

Put a red? > 50mA led in series to either one MagicJack wire ? That I have not tried. Should lit when in use; off then not. -no zener- Come back with results/findings... ;)
 
Last edited:

SparkyCal

Mar 11, 2020
863
Joined
Mar 11, 2020
Messages
863
Thank-you. I have already built this and now its wire is snaking through my desk. I will try a different build next time I rearange my desk. It would be difficult to retrieve at this point.
 

crutschow

May 7, 2021
984
Joined
May 7, 2021
Messages
984
Put a red? > 50mA led in series to either one MagicJack wire
That's a good idea.
The LED will light when the phone is off-hook, and it will take no power when the phone is on-hook.

You could use a smaller LED (such as 20mA rated) in parallel with a resistor (say 100Ω) to keep the LED current below its rating.
 

SparkyCal

Mar 11, 2020
863
Joined
Mar 11, 2020
Messages
863
Attached is what I believe to be a multi coloured LED. I don't know anything about how to hook these up. Is it possible to use this LED to flash a different color when the phone is on hook as opposed to off?
 

Attachments

  • IMG_5288.jpg
    IMG_5288.jpg
    21.6 KB · Views: 6

Audioguru

Sep 24, 2016
3,656
Joined
Sep 24, 2016
Messages
3,656
Of course the 4-wires LED can produce different colors at different times because it has 3 LEDs (red, green and blue) inside. You can even activate 2 or 3 colors at the same time to make many more colors. You can connect the activating circuit to your "Magic jack" but not to an ordinary phone line.

I have a wireless phone (with answering machine) that has a "line in use" LED on its base station but not on the portable handset.
 

crutschow

May 7, 2021
984
Joined
May 7, 2021
Messages
984
Attached is what I believe to be a multi coloured LED. I don't know anything about how to hook these up. Is it possible to use this LED to flash a different color when the phone is on hook as opposed to off?
Need to know how the LED connects internally to the leads.
 

SparkyCal

Mar 11, 2020
863
Joined
Mar 11, 2020
Messages
863
@AG- mine handset has a Line in Use text, but it is so DIM that is hard to see. That's why I sought another solution.

@crutschow- I think the LED I posted was part of a beginner's electronics kit that I have long discarded. Thus, I have no specs on it.I plan to look up some YouTube videos once I have a chance
 

SparkyCal

Mar 11, 2020
863
Joined
Mar 11, 2020
Messages
863
Bertus. I think you are right in that it came with an Audrino kit
 

SparkyCal

Mar 11, 2020
863
Joined
Mar 11, 2020
Messages
863
So, is this a matter of splitting the + lead three ways and giving each lead a different step down resistor according to Ohms law?

I want to be careful cause I only have one of these.
 

SparkyCal

Mar 11, 2020
863
Joined
Mar 11, 2020
Messages
863
Thought more about this. As the voltage changes when the phone is off hook, I probably need only one resistor to the + lead, but it has to trigger a different colour when the phone is picked up. It doesn’t matter to me which colours but I’d prefer blue and red.
 

crutschow

May 7, 2021
984
Joined
May 7, 2021
Messages
984
Below is the LTspice simulation of a circuit that should work for you using two colors of the tri-color LED.
The blue LED draws about 2mA when the phone is on-hook [green trace low], (which shouldn't affect the MagicJack operation), and the red LED draws about 10mA when off-hook.
(Note that this assumes the LED is common cathode, which needs to be determined.
The circuit can be easily modified to accommodate a common anode LED if needed.)

upload_2021-8-17_17-27-24.png
 
Last edited:
Top