#81 Is indeed a relay. These were used in telephone exchanges of the type Bell BTMC 7EN. A type of exchange I used to work in as a technician ages ago. The upper photo show the wire-wrap terminals. An electric drill like kind of machine was used to wrap wires around the leads. The leads were shaped so that the sharp edges would cut into the wrapped wire to make a sound electric connection without the need for soldering. Each 'switch' in this type of relay consisted of pairs of wires with tiny silver tipped contacts. The trick was that with two contacts the last one to open would eventually 'burn-in' while the other remained unaffected making sure a 'noise free' connection could be made even after significant wear of the contacts. These relays could be operational for fourty years or more without interruption or malfunction. Switching billions of times before being scrapped in the past decade for being an outdated technology.
10/28/2004 6:51 AM
Anonymous said...
82: I'm fairly sure is a lathe tool gauge, used to check the tip angle when you grinding a tool for cutting threads.
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6 Comments -
Old telephone microphone (inside handset mouthpiece)
8/16/2004 11:36 AM
Correct, it's from an old telephone.
Rob
8/17/2004 4:41 PM
#81: wire spring relay used in Telco. Industry--top picture is of terminals that correspond to the relay contacts.
8/28/2004 9:05 PM
#80 is the cutters from a pencil sharpener.
8/29/2004 9:47 PM
#81 Is indeed a relay. These were used in telephone exchanges of the type Bell BTMC 7EN. A type of exchange I used to work in as a technician ages ago. The upper photo show the wire-wrap terminals. An electric drill like kind of machine was used to wrap wires around the leads. The leads were shaped so that the sharp edges would cut into the wrapped wire to make a sound electric connection without the need for soldering.
Each 'switch' in this type of relay consisted of pairs of wires with tiny silver tipped contacts. The trick was that with two contacts the last one to open would eventually 'burn-in' while the other remained unaffected making sure a 'noise free' connection could be made even after significant wear of the contacts. These relays could be operational for fourty years or more without interruption or malfunction. Switching billions of times before being scrapped in the past decade for being an outdated technology.
10/28/2004 6:51 AM
82: I'm fairly sure is a lathe tool gauge, used to check the tip angle when you grinding a tool for cutting threads.
9/30/2005 8:18 AM