What notable telecommunication device did Almon Strowger invent?
In the late 1800 s Almon Strowger patented the first electrical-mechanical switch allowing users to automatically connect to a party without operator assistance. Electrical/mechanical switching helped independent phone companies compete with American Bell who failed to implement automatic switching until 1919. As late as after World War II, you could still find manual-switching systems. Three buttons telephone The earliest electrical-mechanical phone device was difficult to use: it had three buttons to push for its signal. Soon a rotary dial replaced it, sending pulse signals to the switch at a ten-pulse-per-second rate as the dial loaded back into position. You can still find a few rotary phones today, but they are rapidly disappearing. Rotary dial phone Replacing the rotary dial phone is a push-button phone that operates as a dual tone multi-frequency (DTMF) signaling device. With a push-button phone, pushing a button results in creating one of two tones: a low frequency tone or a hi
