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Electronics => Beginners => Topic started by: jmctech on February 27, 2018, 02:57:43 am

Title: C556 and C546 transistor
Post by: jmctech on February 27, 2018, 02:57:43 am
Hello,

I have been tasked with trouble shooting a board for a obsolete machine, the board controls a couple of motors, looks like current limiting resistors for the motors failed short and over loaded the main transistors (bvd64b & bvd67A) and these transistors pictured which were hooked to the base of the main transistors. My question is, I was able to find c546 transistors in a cross reference, but all I can find for the 556 is BC556. I have not been able to find any info on a c556. Are these BC### and the B is just not on the case? Or are they different?(https://uploads.tapatalk-cdn.com/20180227/8ed3647111281630cc5cdc93f3648a0e.jpg)

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Title: Re: C556 and C546 transistor
Post by: amspire on February 27, 2018, 03:03:03 am
It is the BC546 (NPN general purpose) and BC556 (PNP general purpose) transistors. Originally designed by Philips.
Title: Re: C556 and C546 transistor
Post by: jmctech on February 27, 2018, 05:20:56 am
Quote from: amspire on February 27, 2018, 03:03:03 am
It is the BC546 (NPN general purpose) and BC556 (PNP general purpose) transistors. Originally designed by Philips.
Thank you

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Title: Re: C556 and C546 transistor
Post by: Peabody on February 27, 2018, 06:17:23 am
Could be 2SC546 and 2SC556.
Title: Re: C556 and C546 transistor
Post by: amspire on February 27, 2018, 06:30:31 am
Quote from: Peabody on February 27, 2018, 06:17:23 am
Could be 2SC546 and 2SC556.
They are Philips BC546/556. I have a some Philips BC557B transistors with the silvered front and the same PH code.