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Re: AppleColor RGB all-red display
- Subject: Re: AppleColor RGB all-red display
- From: Michael J. Mahon <mjmahon@aol.com>
- Date: Wed, 19 Oct 2011 16:08:48 -0500
- Newsgroups: comp.sys.apple2
- References: <j7m45u$u64$1@speranza.aioe.org>
- User-agent: NewsTap/3.2 (iPhone/iPod Touch)
- Xref: news1.google.com comp.sys.apple2:18572
Alex Freed <alex_news@alexfreed.com> wrote:
> On 10/18/2011 10:41 AM, D Finnigan wrote:
>
>> I just researched the transistor number, and it appears to be a standard
>> part: C2688.
>>
>> <http://search.digikey.com/us/en/cat/discrete-semiconductor-products/transistors-bjt-single/1376376?k=c2688>
>
> Standard, yes. But not a stocked item. Nothing magical about it: easy to
> find a substitute. Key parameters are 300V, 10 Watt, 200 mA max current,
> hFE 40 to 150 and 50 MHz.
>
> http://alltransistors.com/crsearch.php?mat=Si&struct=npn&pc=10W&ucb=300V&uce=300V&ueb=5V&ic=0.2&tj=150%C2%B0C&ft=50MHz&cc=3&hfe=40/160&mnf=&caps=
>
> 81 results found :)
>
> -Alex.
Wow! That seems inordinately beefy for a video output transistor. ;-).
10W? And 300v seems like a lot for a transistor stage that only needs to
drive a CRT grid/cathode...
Sounds like a significant overdesign.
-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon