BACKGROUND:
To many this old semiconductor is "junk" but I am big on reusing or repurposing old electronic components and hardware, particularly from the point of view of sustainability.
Sustainability far more than NOT burying waste material back into the earth but consciously recognising the energy expended to create the item through it's various "stages" in life, beginning with the raw materials being extracted from the earth, processed, finished and then fitted into equipment - every single step used energy which is referred to as embodied energy.
To give an approximate representation of how much energy was used in the WHOLE production process of an item, I have created what I refer to as the Ee (Embodied Energy) value, measured in Mj
The Ee value is an approximation only and usually measured in Mj.
Coming up with an Ee value is an attempt to take into account the energy used for extracting and processing of the raw materials, manufacturing of the component, distribution of the component(s) and final assembly of the component. In fact the measurement of Ee can become extremely complicated and technical, many tertiary institutions are involved in this specialised field of science.
I have used various reliable sources online to arrive at approximate Ee values, these are approximations and the sole purpose is to raise awareness of the extraordinary energy consumed in the creation of various electronic components and hardware - it may give you cause to think twice before wasting all that energy and burying it in the ground, with the possible side-effects of poisoning the environment due to leeching.
HERE is a page I have created which gives some tables and more detailed information about specific Ee values for different materials plus a link which you can use as a starting point to investigate Ee for yourself.
This old and difficult to source (at a reasonable price) transistor was extracted from the JVC BR-6400TR Professional VCR machine which has recently been on the "operating table"
MATSUSHITA - Medium Power Darlington Transistor
Type: 2SD837
NPN
Vcb 60V
Vce 60V
Pc 40W
Ic 3A
hFE minimum 1000 - not able to be measured by my equipment, see below
TO220 package
COSMETIC CONDITION:
USED
Clean
Leads de-soldered relatively cleanly
TESTING:
Basic testing indicates the device is functional
Note that due to this darlington transistor's architecture (internal resistor between the Emitter Base junction & Emitter) it is not possible to obtain an accurate hFE reading with my simple transistor tester ... see the internal resistor indicated in the datasheet below (lightly highlighted)
As each device was tested, the hFE result has been written onto the rear heatsink area although in the case of this 2SD837, the hFE results are pretty meaningless.
Lead lengths 7.8mm (the two shortest leads) and 13.25mm for the single transistor with longer leads, all are reasonably clean, non-oxidised - perfectly solderable
These transistors has now been packed in a sealed clear plastic packet awaiting a new purpose in life!
