Help identify this component..

Thread Starter

bushrat

Joined Nov 29, 2014
209
Hello everyone,

I have few of these parts, and I have no idea what they are.
They look like oversize transistors (TO-18)
Writing on the side says SD7014, but I cannot find any datasheet for it.

IMAG1371.jpg

Microscope zoom.
IMAG1372.jpg
 

jpanhalt

Joined Jan 18, 2008
11,087
Does it have a window over the presumed "active area?"

If it has a window on it, then it is probably a light detector. If there is no window, it may still be a light detector, but it may also be a pressure detector. In the 1990's, I got several similar looking sensors form Electronic Goldmine that were from radiosondes. I will pick one up on my next trip to Cleveland.

John
 

Lundwall_Paul

Joined Oct 18, 2011
236
My best guess is-- phototransistor is a light-sensitive transistor. A common type of phototransistor, called a photobipolar transistor, is in essence a bipolar transistor encased in a transparent case so that light can reach the base–collector junction.
 

ian field

Joined Oct 27, 2012
6,536
My best guess is-- phototransistor is a light-sensitive transistor. A common type of phototransistor, called a photobipolar transistor, is in essence a bipolar transistor encased in a transparent case so that light can reach the base–collector junction.
If its intended application was known - that might clear things up.

Photodiodes are very fast - phototransistors are a lot slower.

The case style can be inconclusive - photodiodes often have 3 leads to conform to a case style standard and to prevent reversed insetion, phototransistors sometimes don't have a base lead brought out of the case.

With the 6-pin DIL opto-couplers; most use a photo transistor, all the pins are there but the base pin isn't connected on some versions.
 

ian field

Joined Oct 27, 2012
6,536
The base pin (or the middle pin) is connected to the case.
The first thing to do is use a DMM Ohms range to check for any path between the case pin and either of the other pins.

Then check the other pins for any resemblence to a diode - bear in mind you might get different results depending on whether the active area is exposed to light.
 
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