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Electronics => Beginners => Topic started by: Bskitter on August 08, 2017, 11:43:44 am

Title: SMD Transistor Identification
Post by: Bskitter on August 08, 2017, 11:43:44 am

Hey Guys I am doing some work on a Computer Power Supply and I need to identify the control transistor for the relay circuit.

(http://i.imgur.com/TuCjvgF.jpg)

Can anyone please help me out ?

Byron

Title: Re: SMD Transistor Identification
Post by: Kjelt on August 08, 2017, 11:53:16 am

According to the smd code book (google ;) ) it is probably a FMMT-A42R high voltage transistor.

Title: Re: SMD Transistor Identification
Post by: perieanuo on August 09, 2017, 07:58:42 pm

No way, it's nfet or pnp/npn just verify relay wiring. If it's just relay bobbin any nfet or bipolar with Vcc/Ic respect will do

Envoyé de mon HUAWEI NXT-L29 en utilisant Tapatalk

Title: Re: SMD Transistor Identification
Post by: floobydust on August 09, 2017, 09:01:58 pm

I got SMD marking code 7E as PNP MMBTA92 (https://assets.nexperia.com/documents/data-sheet/MMBTA92.pdf)
I got SMD marking code 3E as NPN FMMTA42 (https://www.diodes.com/assets/Datasheets/FMMTA42.pdf)

OP should check if the emitter goes to GND, I expect that and an NPN.

Title: Re: SMD Transistor Identification
Post by: Kjelt on August 10, 2017, 05:46:23 am

What is the coil voltage of the relay?