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General Chat => Technical Area => Topic started by: level42 on June 21, 2012, 08:55:52 AM

Title: All Transistors, Nice to find transistor equivalents
Post by: level42 on June 21, 2012, 08:55:52 AM
http://alltransistors.com/

Very handy if you are looking for an equivalent transistor that is still (cheaply/locally) available.

Title: Re: All Transistors, Nice to find transistor equivalents
Post by: level42 on June 21, 2012, 09:15:37 AM
Mmm, I just used it to find a replacement for the 2N6044 used on the Lunar Lander mission light PCB.
For some reason it shows the Hfe of this transistor at 1200 times, but the datasheet for it say 2500 times, quite a difference...... so use with caution. (Hfe means the number of times the transistor amplifies the input signal)

ALWAYS check the datasheets of both transistors after finding an equivalent transistor to confirm they are indeed equivalent.

Here's another nice tool, even though it only translates to the manufacturers own transistors, often with that type you can find other equivalents again.

http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/$$Search?OpenForm
Title: Re: All Transistors, Nice to find transistor equivalents
Post by: level42 on June 21, 2012, 09:28:29 AM
Sometimes you have to "play around" with these tools and google.

F.I. All transistors mentions only the 2N6045 as equivalent for the 2N6044 when I search for 2N6044

When I enter 2N6044 in the NTE site I find the NTE261 as replacement. Checked Datasheet, looks good.
Tried to search it on RS online and they have it, but it's expensive and only available from their Allied partner in the US which means a long delivery time 10 days).

So...I enter NTE261 in All Transistors database and get a whole list of equivalents:
http://alltransistors.com/crsearch.php?mat=Si&struct=npn&pc=65W&ucb=100V&uce=100V&ueb=5V&ic=8A&tj=-&cc=&hfe=1000T&mnf=&caps=TO220

Than it's doing a search with those types on the RS site to see what's available and I find they have the BDW42 form Europe and at a good price:
http://nl.rs-online.com/web/p/darlington-transistor/5452513/?searchTerm=bdw42&relevancy-data=636F3D3226696E3D4931384E4B6E6F776E41734D504E266C753D6E6C266D6D3D6D61746368616C6C7061727469616C26706D3D5E5C772B2426706F3D313326736E3D592673743D4D414E5F504152545F4E554D424552267573743D62647734322677633D424F544826

My experience is that transistors starting with the number 2 are usually "American" ones. You have more chance of finding the ones starting with B in Europe.

Final step is to compare the datasheets of both the BDW42 and 2N6044 and it looks fine. Especially since in this application the transistor is used only as a switch to turn the lamp on and off the specs are not extremely critical, so these should work fine.

Title: Re: All Transistors, Nice to find transistor equivalents
Post by: level42 on June 21, 2012, 09:59:32 AM
...even better, the datasheets indicated that the BDW42 is somewhat over specced in max. voltages (100V) compared to the 2N6044 (80V).

The datasheet indicated that there is also a BDW46 which is specced the same as the 42 but at....80V.

Since they are operating at about 10v in this application it's a no brainer to go for the 46.

Turns out RS sells these too, they are even cheaper AND availble per piece, so I ordered 4.
http://nl.rs-online.com/web/p/darlington-transistor/5450113/?searchTerm=bdw46&relevancy-data=636F3D3226696E3D4931384E4B6E6F776E41734D504E266C753D6E6C266D6D3D6D61746368616C6C7061727469616C26706D3D5E5C772B2426706F3D313326736E3D592673743D4D414E5F504152545F4E554D424552267573743D62647734362677633D424F544826


If there are any subtle differences between the 2N6044 which would be visible I can always replace all the transistors, else I have enough spares for the coming 40 years ;)
Title: Re: All Transistors, Nice to find transistor equivalents
Post by: Blanka on June 21, 2012, 11:18:10 AM
Don't get how it works yet. When I search 945C I don't see anything.
I have a very old DOS program, Torbase, that seems more reliable and efficient. But I might need to dig a bit more into this site.
Title: Re: All Transistors, Nice to find transistor equivalents
Post by: level42 on June 21, 2012, 11:48:56 AM
945C doesn't sound like a transistor number to me.

In this case you can try leaving of the trailing letter, in this case the c.

Maybe it's 2N945 ?

Did you find it in TORBASE ? Not sure if it was that program, but I remember I once bought a software transistor database in the early 90s while I worked at a Taiwanese computer monitor company and after having searched ALL the transistors that were used in "our" monitors and finding ZERO, I sent it back with a nice note and a demand to get our money back.... :)

There are also apps that promise to provide transistor bases (Dutch electronics magazine Electuur has one f.i.) The thing is that these often only produce the specs of the transistor and not equivalents, and also often pretty limited databases. Plus they cost money....
Title: Re: All Transistors, Nice to find transistor equivalents
Post by: Blanka on June 21, 2012, 03:31:31 PM
F.I. All transistors mentions only the 2N6045 as equivalent for the 2N6044 when I search for 2N6044

Torbase says BD650 or BD702
RS comes up with this:
http://nl.rs-online.com/web/p/darlington-transistor/5449882/
mmmmm tube of 50
Title: Re: All Transistors, Nice to find transistor equivalents
Post by: speleo_de on June 21, 2012, 03:57:35 PM
You need NPN Darlingtons in TO220 with >=5 Amps and >=80 Volts. Hfe doesn't really matter for Darlington.

These are massively used in Pinballs, but they are working as well in Video games :-) and they are cheap.
5 Amps: TIP121 (80V) or TIP122 (100V)
8 Amps: TIP131 (80V) or TIP132 (100V) or BDX53B (80V) or BDX53C(100V)

Title: Re: All Transistors, Nice to find transistor equivalents
Post by: level42 on June 21, 2012, 04:46:07 PM
Yikes !!!!!! The 46 is PNP.......duuuuuuhhh....

Title: Re: All Transistors, Nice to find transistor equivalents
Post by: level42 on June 21, 2012, 06:07:39 PM
I assume you meant that info for me Andreas ?

Found the TIPs at RS and indeed, even cheaper, a lot cheaper :)