Timeline for Voltage controlled oscillator design: NPN transistor BC238BP vs BC238 equivalency
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 6, 2020 at 8:48 | vote | accept | Nabla | ||
| Nov 6, 2020 at 8:32 | comment | added | Bimpelrekkie | @Reinderien pre-amp sections that are very sensitive to hfe I agree but then you would need to use NPNs which have an \$h_{fe}\$ that falls within a certain (small) range. You would need to "hand pick" these NPNs and/or buy pre-selected ones, all that is quite expensive. My preference would be to try to avoid that so that \$h_{fe}\$ doesn't become so critical. | |
| Nov 5, 2020 at 21:21 | comment | added | Jerry Coffin | Going well beyond suffixes, many (most?) circuits that specify a 2N3904 will work perfectly well if you use a 2N2222 instead. The 2N2222 is generally more expensive, but if you have a few dozen lying around. Going the other direction often works as well, but you have to be more careful (the 3904 has a lower limit collector current). | |
| Nov 5, 2020 at 21:10 | comment | added | Reinderien | Generally I agree with this. almost any NPN transistor is somewhat of a stretch. Surely there are pre-amp sections that are very sensitive to hfe and won't just work with a general-purpose BJT. | |
| Nov 5, 2020 at 20:48 | history | answered | Bimpelrekkie | CC BY-SA 4.0 |