Here is a teleremote circuit which enables switching on and off of appliances through telephone lines. It can be used to switch appliances from any distance, overcoming the limited range of infrared and radio remote controls.
http://www.electronic-circuits-diagrams.com/remotecontrolsimages/remotecontrolsckt2.shtml
Here is a teleremote circuit which enables switching on and off of appliances through telephone lines. It can be used to switch appliances from any distance, overcoming the limited range of infrared and radio remote controls.
http://www.electronic-circuits-diagrams.com/remotecontrolsimages/remotecontrolsckt2.shtml
Designed for a model hovercraft, the controller consists of a Dual-tone multifrequency (DTMF) encoder based on the UM91214 Telephone dialler IC.
http://wiredworld.tripod.com/tronics/remote_control.html