Problem on telephon hold circuit..... - Electronic Circuits Projects Diagrams Free

smorteza · 13th March 2004, 03:09 AM

Hi.
What should I do to hold four telephone_line with one hold_circut that none of them can hear speaking of other lines.
Thanks.

Russlk · 13th March 2004, 03:22 AM

To hold the line "off hook" you just have to put a current load on it. Use an opto isolator with transistor output and resistor load on each line. Do you have a power supply for the LEDs?

crazymonkey · 13th March 2004, 09:43 AM

Check out this site http://www.aaroncake.net/circuits/phonhold.htm. I don't know if it will work, you'll prob have to build 4 as well.

ljcox · 14th March 2004, 03:22 AM

You can hold the line by connecting a 470 Ohm 2 Watt resistor across the line.

Len

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13th March 2004, 03:09 AM	#1
smorteza	Problem on telephon hold circuit..... Hi. What should I do to hold four telephone_line with one hold_circut that none of them can hear speaking of other lines. Thanks.

13th March 2004, 03:22 AM	#2
Russlk	To hold the line "off hook" you just have to put a current load on it. Use an opto isolator with transistor output and resistor load on each line. Do you have a power supply for the LEDs? __________________ see my website: www.geocities.com/russlk

13th March 2004, 09:43 AM	#3
crazymonkey	Check out this site http://www.aaroncake.net/circuits/phonhold.htm. I don't know if it will work, you'll prob have to build 4 as well.

14th March 2004, 03:22 AM	#4
ljcox	You can hold the line by connecting a 470 Ohm 2 Watt resistor across the line. Len