Stupid question about transistor sockets

Started by Badcircuit, May 21, 2023, 08:49:58 PM

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Badcircuit

Hi guys,

I've got a board that is calling for a traditional 3 legged transistor; but, it has 4 holes.  I see references to a socket but all the ones I have seen are just for one leg at a time.  If any of this makes any sense to anybody, I would appreciate the help.

Thank you!

Rob Strand

Without anymore info I can only guess the 4-pin socket is used to accommodate different transistor pinouts without having to bend the leads around.
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

bluelagoon

the pcb board likely has 4 holes to accomodate different pinout transistors , whereby 2 of the 4 holes will be connected by a trace on the pcb, for the same leg of the transistor, depending on the pinout, by giving this option it often saves twisting one transistor leg around another to fit on the pcb. What you need to do is figure out what pins on the transistor you are using correspond to the correct 3 of 4 transistor pads on your pcb, and in the easiest format to fit on the board without twisting pins around each other.
Check the image attached, you can see that there are 4 pads to the Fet transistor pinout being SDGS, where both the outside S (Source) pads are connected by a trace, this configuration allows for 4 different possible transistor pinout variations being SDG, DGS, SGD and GDS, without a need for twisting pins around each other to place correctly on the PCB . Hope this answers your question.




GibsonGM

If you need help figuring out how to orient the transistor you have to the board - post the build documentation & schematic and we can make sure it goes in right way round :) 

Not clear if the PCB has pin labels like the one blue lagoon posted above this.
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amptramp

The 3-pin transistor sockets i have look like this:



Is this what you are talking about?

matopotato

Quote from: amptramp on May 22, 2023, 07:57:32 AM
The 3-pin transistor sockets i have look like this:



Is this what you are talking about?
Kind of looks like your avatar "tree", @amptramp.  ;)
"Should have breadboarded it first"