The package is a TO-202 with the tab cut off or at least the MPS-U51 uses a TO-202 package. Be careful when you replace it because the pinout is EBC which is deprecated in power transistor packages.
Ic = 2.0 A Vceo = 30 V Pd = 1 W @ Ta 25 C hfe = 60 @ 0.1 A Ft = 50 MHz min This is a very non-critical application. I agree with Brooke Clarke that a 2N4403 will probably work fine. If you want something closer then there are any number of TO-126 and TO-225 transistors like the MJE170 which will work but again, be careful of the pinout. On Sun, 22 Jan 2012 10:41:23 -0800, Chris Albertson <[email protected]> wrote: >I have an eBay HP5328A counter with two dead digits on the display. I >figured out the problem was two dead transistors. I can swap >transistors with a good digit and the problem moves. > >I'd not worked on LED displays before. Turns out only one digit is >lit up at a time, they strobe the digits in sequence. The dead >transistor is the one that controls the all the anodes in the >7-segment LED module. The service manual describes the transistor >like this: "part number = 1853-0326", "description = TRANSISTOR PNP >SI ... FT-50MHZ" >The p/n 1853-0326 cross references to a Motorola MPS-U51. The MPS-U51 >data sheet matches the part that fails so I'm sure I got a correct >cross ref. >I took a photo of the dead transistor. It is on .1" perf board for >scale. You can read the "3-326" p/n and see the Motorola "M" logo. >http://www.dropbox.com/gallery/28915695/1/HP5328A?h=da35c1 > >I look up the spec in the mps-u51 and see it is a to-220 like case and >can handle 1W. I'm really surprised it burned out as I doubt an LED >requires 1W even if showing an "8". Reading the mps-u51 spec sheet I >see it has a low saturation voltage. Maybe that is why the selected >it as it is being driven by 7400 TTL logic that goes through a >connector and has some resistors involved. > >Question: These seem to be hardtop find. Can anyone suggest a good sub" _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
