We know what you meant. It’s the only time you don’t have to 100% test a batch - when they come from Digikey, et al. Well, parametric test a sample and make sure they’re all the same anyway.
So why bother with a 100% test at all? When you do run across a batch of 70 MJL1302’s for $100. It’s worth getting a couple (even at $5 a pop) to crack open and otherwise put through their paces on the chance that that they are good.
So why bother with a 100% test at all? When you do run across a batch of 70 MJL1302’s for $100. It’s worth getting a couple (even at $5 a pop) to crack open and otherwise put through their paces on the chance that that they are good.
Hey Chris, I have used MJE15032/33G since the Motorola days but if you have not noticed, many OnSemi hi-power bjt parts are on long back order, (MJE15032G as one example), thus of late, they are not a very reliable supplier for a manufacturer. A service shop can manage better than a mfr. I op. as a mfr not a service shop, so need a more reliable & greater supply of said parts. I have managed to find a US source that sells them however but do not need 1000's or I'd be in trouble. So on to qualification process,
I have a new amp design on the bench, in which I can compare them, op. in circuit, under load and measurements, stay tuned ...
I have a new amp design on the bench, in which I can compare them, op. in circuit, under load and measurements, stay tuned ...
Hi Rick,
I hear you. Have you tried MJE15034 and 15035? That's what I went to wehn those were on back order. Sometimes I have to order compliments from two different distributors. What PITA !!!
New Toshiba part numbers may work, I haven't surveyed them yet. How many do you try to keep on-hand?
Anyway, keep us tuned in. I'm hoping these shortages ease as we move away from COVID, but that damage is long lasting. The cure may have killed the patient.
I hear you. Have you tried MJE15034 and 15035? That's what I went to wehn those were on back order. Sometimes I have to order compliments from two different distributors. What PITA !!!
New Toshiba part numbers may work, I haven't surveyed them yet. How many do you try to keep on-hand?
Anyway, keep us tuned in. I'm hoping these shortages ease as we move away from COVID, but that damage is long lasting. The cure may have killed the patient.
The 034 and 035 are only rated 4A instead of 8. Probably because the gain falls off too fast at 8A due to the processing differences required to get that high a VCEO. If you only need 1 amp of collector current they are in general better than the 032/033. Above 1A, the 032/33 are better at low Vce where the higher current is typically drawn. It’s similar to the difference between the MJL4281 and original 3281.
How a second source is going to do is a crap shoot. The ON parts don’t really need any special sauce that can only be found within their walls. Other makers copies will be different in some ways, but whether that matters is design dependent. I guess all one can do is try. Just DONT use anything marked “ON” that you can’t verify in some way. A true copy that could be good would be marked by its maker’s logo, and come through their designated channels. ISC for instance, makes stuff that is just fine. And others you wouldn’t touch with a 20 foot pole.
How a second source is going to do is a crap shoot. The ON parts don’t really need any special sauce that can only be found within their walls. Other makers copies will be different in some ways, but whether that matters is design dependent. I guess all one can do is try. Just DONT use anything marked “ON” that you can’t verify in some way. A true copy that could be good would be marked by its maker’s logo, and come through their designated channels. ISC for instance, makes stuff that is just fine. And others you wouldn’t touch with a 20 foot pole.
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Mouser and Digikey both have approximately half of every complementary pair in stock. Funny how one stops being depleted about the same time one runs out completely. Then they hang onto those residuals until hey have both back in.
Looks like a pretty good shipment from ON for all sorts of types is coming to Mouser in April. I plan on ordering two more tubes of MJL21194, as that will give me equal-ish quantities on both. I’d have them on backorder already, but I honestly dont know which address they’ll need to be shipped to - here or the new place. The BUILD won’t happen till I’m at the new place, because there simply isn’t room n my old shop to set up a proper production line, and most everything is boxed up. That “production run” is likely a year or more out still so if I miss this shipment (ie they all get gobbled up before I get an order in) it’s not the end of the world. PCBs are in final optimization now, and probably do a big (for me) order to JLC after the move too.
Man, am I glad I got the last of the 2SB1647 Sankens. It got designed into two more things (a 150W sub in progress for my small temporary office) and a batch of 4 2x200W class H dedicated for HF driver use in the PA rigs (so TIP142/7 is less desirable). Looks like they will end up going on MOQ when stock is gone. Of course, DK still has some of the NPNs, which they may be sitting on for a while now.
Looks like a pretty good shipment from ON for all sorts of types is coming to Mouser in April. I plan on ordering two more tubes of MJL21194, as that will give me equal-ish quantities on both. I’d have them on backorder already, but I honestly dont know which address they’ll need to be shipped to - here or the new place. The BUILD won’t happen till I’m at the new place, because there simply isn’t room n my old shop to set up a proper production line, and most everything is boxed up. That “production run” is likely a year or more out still so if I miss this shipment (ie they all get gobbled up before I get an order in) it’s not the end of the world. PCBs are in final optimization now, and probably do a big (for me) order to JLC after the move too.
Man, am I glad I got the last of the 2SB1647 Sankens. It got designed into two more things (a 150W sub in progress for my small temporary office) and a batch of 4 2x200W class H dedicated for HF driver use in the PA rigs (so TIP142/7 is less desirable). Looks like they will end up going on MOQ when stock is gone. Of course, DK still has some of the NPNs, which they may be sitting on for a while now.
Hi, I'm Sergio from Italy and I'm new of this thread, I bout a dozen of MJ21294 from Quest components , and I'm wondering if someone have tested this device (double Die) for 350W of power, in some diy project.
Unfortunely this device produced by New jersey semicon was not double die but single, and it seem a another similar MJ21194 rated for 250W instead of 350W.
Sorry for my bad english
ciao Sergio
Unfortunely this device produced by New jersey semicon was not double die but single, and it seem a another similar MJ21194 rated for 250W instead of 350W.
Sorry for my bad english
ciao Sergio
The 21294 never went anywhere, and was obsoleted very quickly. Recall one of the corollaries to Murphy’s Law - If nobody uses it there’s a reason.
Motorola/ON experimented around with double die versions of their high power darlingtons, and still continued to make them for a long time - ie, MJ11032/3. As amplifiers, they were no better than the single die version (MJ11015/6). One die hogs all the current at any Vce>10V. As switches, they worked well - doing the full 50A, but only at very low VCE. But the MJ21194 is not a switching transistor, and the 21294 probably had the same problems as 11032 did at high Vce. If the SOA is no better than the single die version, why eff with the double?
NJ Semiconductor (affiliated with the same company as NTE, BTW), as is Solid State Inc, may be selling 21194 as a 21294, because there is no real improvement in SOA.
Motorola/ON experimented around with double die versions of their high power darlingtons, and still continued to make them for a long time - ie, MJ11032/3. As amplifiers, they were no better than the single die version (MJ11015/6). One die hogs all the current at any Vce>10V. As switches, they worked well - doing the full 50A, but only at very low VCE. But the MJ21194 is not a switching transistor, and the 21294 probably had the same problems as 11032 did at high Vce. If the SOA is no better than the single die version, why eff with the double?
NJ Semiconductor (affiliated with the same company as NTE, BTW), as is Solid State Inc, may be selling 21194 as a 21294, because there is no real improvement in SOA.
NTE (and all their affiliates) get their stuff from Wherever They Can these days. If multiple solutions exist, its the low bidder. People are making ON copies these days. Newer stuff like MJE15023/3 and even MJW3281 out of China now. Mospec and others making the old JEDEC stuff (And some of the MJ TO-3’s). ISC making “clones” of the Jap stuff (Sanken, Toshiba, Hitachi). CDIL India making a lot of generics. That’s what you get. The quality is all over the map. Most of the old stuff is relatively “easy” to make (say TIP41 or 2N3055 easy) so it will likely work to the data sheet spec. For higher performance stuff don’t expect miracles.
Back in the early days of ECG cloning wasn’t as common. You could only get a 2SD424 from Toshiba. So if you bought an ECG284 it usually was a D424 with the type number sanded off and labeled “SYL ECG284”. But it would be from an end run or possibly a spec fall out - Ive still got sone that fall out of hFE range of R grade. Got them all at the same time, but not suitable for paralleling. It could just as easily be a similar type, if there was any supply chain problems or if they happened to get a good deal on something like a 2N3773 (again, end run, spec fall out, surplus). Yeah, I’ve seen aluminum cased ECG284’s being sold back in the early 80’s as well as ones in the Toshiba-specific package. Those were either Fairchild or Motorola. Bitter enemies in those days too. Funny how they ended up in bed together.
Back in the early days of ECG cloning wasn’t as common. You could only get a 2SD424 from Toshiba. So if you bought an ECG284 it usually was a D424 with the type number sanded off and labeled “SYL ECG284”. But it would be from an end run or possibly a spec fall out - Ive still got sone that fall out of hFE range of R grade. Got them all at the same time, but not suitable for paralleling. It could just as easily be a similar type, if there was any supply chain problems or if they happened to get a good deal on something like a 2N3773 (again, end run, spec fall out, surplus). Yeah, I’ve seen aluminum cased ECG284’s being sold back in the early 80’s as well as ones in the Toshiba-specific package. Those were either Fairchild or Motorola. Bitter enemies in those days too. Funny how they ended up in bed together.
That's my experience with ECG and NTE. Really poor reliability some times. Forget matching as you never knew if the original parts were the same.
They only people happy with ECG were TV repair people, and some industrial users. Audio people who didn't know what they were doing would use ECG, and later NTE. Fat, dumb and happy.
If I see any ECG or NTE transistors in a unit for repair, they are on the replace list - period. Otherwise I bail on doing the job.
They only people happy with ECG were TV repair people, and some industrial users. Audio people who didn't know what they were doing would use ECG, and later NTE. Fat, dumb and happy.
If I see any ECG or NTE transistors in a unit for repair, they are on the replace list - period. Otherwise I bail on doing the job.
Scenario: Mark and Warren looking for a couple of 2SB56’s to fix an old preamp. Want parts today if possible - next MCM order not ready to go out yet, and certainly not for a couple of 60 some odd cent parts. They go into local parts store. Timeframe: 1985.
Warren: “Got any 2SB56’s?”
Shopkeeper: “Got an ECG number on that?”
Mark and Warren (together) : “But ECG is PHILIPS, and PHILIPS isn’t worth a $***!”
Walks out the door…..
He’ll still leave me prank voicemails to this day. “Got an ECG number on that?”
Warren: “Got any 2SB56’s?”
Shopkeeper: “Got an ECG number on that?”
Mark and Warren (together) : “But ECG is PHILIPS, and PHILIPS isn’t worth a $***!”
Walks out the door…..
He’ll still leave me prank voicemails to this day. “Got an ECG number on that?”