Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Solution for Phone-In-Use indicator

Status
Not open for further replies.

e2k

Newbie level 1
Joined
Dec 14, 2005
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,286
I want a "telephone in use" indicator circuit that does not Interrupts internet speed or modem when I am using internet from modem?
 

E-design

Advanced Member level 5
Joined
Jun 1, 2002
Messages
2,014
Helped
507
Reputation
1,016
Reaction score
408
Trophy points
1,363
Activity points
14,193
Re: Need Circuit Help

You have to sense the voltage on the line. If the modem is using the line the voltage will be low 11-17VDC. If the line is available, the voltage will be around 48VDC. So your circuit could easily lockout the phone by activating a relay when the modem is in use.
 

IanP

Advanced Member level 5
Joined
Oct 5, 2004
Messages
7,929
Helped
2,311
Reputation
4,624
Reaction score
531
Trophy points
1,393
Location
West Coast
Activity points
66,416
Re: Need Circuit Help

Try "Telephone-related ASCII Schematics" at:
**broken link removed**
and have a look at several options of: "Phone-In-Use indicator" ..

Regards,
IanP
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top