Sustainability is the name of the game! Anything (that has been tested and still functioning properly) should be repurposed creating saving in wasted Ee and reducing the poisoning our environment when items are buried in the earth at the local tip needlessly.
Never heard of Ee? It is a concept that creates a measurement of ALL things (not just electronics) that humans have made and the energy used in obtaining the raw material, processing the materials right through to a finished product and even should include the shipping of the item to the distributors/retailers.
If you would like to know more about Ee values, please take a look HERE
HISTORY:
This type of lever keyswitch was the backbone of telephony subscriber switchboards, exchange 'test desks' and auxilliary linesman equipment for many years, I even saw some of these used in old recording studio "talk back" systems ... many many years ago!
Robust, reliable, long operating life and easy to maintain
The switch(s) I have 'dug out' of my "all things olde world telephony" box are all of the same type, DPDT and the action is momentary i.e push down ON, release OFF
This type of action was often used on switchboard 'manual ring' circuits but I have found these on other completely different systems where they were used for talk-back systems i.e push the lever to talk, release and it's silent.
IMPORTANT NOTE:
The user of this switch(s) will need to have the 'screw on' front knob - I cannot find them!
Geez it was a long time ago since I worked with this type of switch, I was looking for the manufacturer and expected to find something like STC or even AWA but alas, although there is a logo, I do not recognise it but I will take a 'educated guess' at this being a PED lever keyswitch.
PED was Pye Electro Devices who supplied parts to the GPO and its suppliers. Why choose them?
A company logo is stamped into the metal (inside & between the contact sets), imagine a triangle with an extra vertical line in the centre and within this shape is a large P
The only other marking (stamped into the metal body) is TP.67.72
PED (United Kingdom) - Lever Keyswitch
Made in United Kingdom
Part number: TP.67.72
Type: Double Pole Double Throw
Action: Momentary i.e not locking
Switch is break-before-make on both contact sets
Leaf type construction with sandwich assembly used. This looks to be of 70's vintage due to the Green plastic being used for the spacers.
Solder terminations to the rear, both hook and hole type.
Front shaft is threaded, waiting for a knob to be fitted (NOT SUPPLIED) - you need the long knob with a centre hole which is threaded, this mates with the switch shaft.
The 4x front panel securing screws ARE supplied
DIMENSIONS:
Body: 63mm length x 18mm wide x 28mm height
Front shaft extends from the body 25mm
Rear solder terminals extend from the body 15mm
Weight: 68g
COSMETIC CONDITION:
USED
Clean (very)
NO corrosion or oxidisation at all - afterall, these were inside the equipment Oak switchboard cabinet and well protected from the environment. Being open frame, it is always best to use these within an enclosure of some type.
Contact points look fine, DC resistance test was also fine - if ever the need arose, these contacts are easy to clean up anyway.
I have now put this nice relic from the mists of telephony into a sealed clear plastic packet, hoping that someone may put them to use once again.
