Instructions for constructing and installing fifteen telephone accessories, including a remote ring indicator, a speakerphone, a scramble, an autodialer, an answer machine, and a telerecorder, are enhanced by pertinent schematicsRemote Ear 25 When RY3 is activated it switches RY2 out of the control circuit of SSW2 and replaces it with RY4. ... R6 a 1M ohms RY1 a 12V spst relay R7 a 470 ohms RY2 a 12V dpdt relay R8 a 100 ohms RY3 a 12V spdt relay C1anbsp;...
|Title||:||Telephone Accessories You Can Build|
|Author||:||Jules H. Gilder|
|Publisher||:||Sams - 1976-01-01|