1854-0003: Material: Silicon NPN Pw = 800 mW Ft = 50 MHz Vceo = 28 V Package = TO-5 Hfe = 60/240 10 mA
No JEDEC part number. On Sun, Aug 9, 2009 at 1:02 PM, Glenn Little WB4UIV<[email protected]> wrote: > 1854-0003 is a good part number. I have a few here that were removed from > equipment. > Possibly someone with the proper equipment could characterize this part and > determine a suitable parametric substitute. > > 73 > Glenn > WB4UIV > > At 11:43 AM 8/9/2009, you wrote: >> >> Double check: "Q11 is marked as 1854-0003." I can't find it in any of the >> HP cross references. >> >> Brian - KD4FM >> >> >> Jim Palfreyman wrote: >>> >>> Hi all, >>> >>> Latest update. >>> >>> With some help and phone calls from Bill the fault seems to have been >>> isolated. I have removed Q11 from inside the oven and it is cactus. Q9 >>> is also very suspect so I'm going to replace that for good measure. >>> >>> Q9 is a 2N1701 in a T08 package. Thanks to various people I should be >>> able to track one down. Q11 is marked as 1854-0003 and that's an HP >>> internal number and all I know. Might have to substitute that one. >>> >>> After all this I have some quality photos and can knock up some good >>> descriptions of the repairs and the 106B internals if anyone is >>> interested. Any websites hanging around that want to take what I have? >>> >>> Regards and thanks to all! >>> >>> Jim Palfreyman >>> >>> >>> 2009/8/9 Adrian <[email protected]>: >>> >>>> Re-read Jim's posts. >>>> >>>> To me it seems clear that he is talking about the 2N1701 Q3 in the upper >>>> right corner of fig. 5-12. >>>> He mentioned that +18 measures high, around 26V. >>>> So, the problem is NOT in the battery charger circuit. >>>> >>>> The purpose of that Q3 is to generate +17.4V (and +7V) from +26V, with >>>> the >>>> base being connected to +18V, thus the emitter voltage of Q3 is +18V - >>>> 0.6 >>>> to - 0.7V. >>>> >>>> The +18V regulator circuit is on the lower left of fig 5-8, A1A4 Outer >>>> Oven >>>> Controller. For a circuit description see 4-40 to 4-44. >>>> >>>> The +18V feed the AC amplifier (A1A2), the +15V through R14 (might be >>>> cooked >>>> if run at 26V for extended time) and CR2 on the same board, the power >>>> amplifier (A1A3), the outer oven temperature control circuit (decoupled >>>> +18V), and the inner oven control cuircuit A1A5. >>>> The 17.4V that are derived from +18V feed the dividers. >>>> >>>> Any adjustments make sense only after fixing the +18V supply. >>>> >>>> Actually, Q3 might as well be shorted. I would first remove it from the >>>> circuit to see if the +18V are then correct. >>>> If not, check the voltages at Q9 and Q7 of A1A4. Q9 is mounted on the >>>> oven >>>> housing cover. >>>> >>>> Regards, >>>> Adrian >>>> >>>> Bruce Griffiths schrieb: >>>> >>>>> christopher hoover wrote: >>>>> >>>>> >>>>>>> The 2N1701 is a general purpose transistor rated at 60V, 2.5A. >>>>>>> >>>>>>> >>>>>> I've mentioned this before, but it bears repeating. >>>>>> >>>>>> If you are having trouble with an old school linear power supply, in >>>>>> many cases you can replace the TO-220 PNP pass transistor *and* the >>>>>> reguatlor circuit (based on a 723 or whatever) with a modern >>>>>> integrated regulator in TO-220 such as an LT1581. Strip the regular >>>>>> board of everything except for the the input and output caps (if they >>>>>> are still good) and wire up a pair of resistors to set the voltage. >>>>>> Add >>>>>> a couple of jumpers to complete the circuit. And then you are >>>>>> good to go. >>>>>> >>>>>> -ch >>>>>> >>>>>> >>>>>> >>>>> That probably wont work in this case. >>>>> The supply is actually an NPN discrete darlington buffered 32V zener >>>>> with a current limit transistor to set the battery charging current to >>>>> one of 2 values. >>>>> With the battery removed the supply output should rise to 32V - 2Vbe - >>>>> a >>>>> diode drop, ie about 29.8V or so. >>>>> The series diode is required to isolate the battery from the regulator >>>>> output when the main fails. >>>>> It should be much quicker and easier to just find suitable transistors. >>>>> >>>>> Bruce >>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>>>> >>>>> >>>>> >>>> _______________________________________________ >>>> 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. >>>> >>>> >>> >>> _______________________________________________ >>> 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. >>> >>> >> >> _______________________________________________ >> 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. > > > _______________________________________________ > 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. > _______________________________________________ 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.
