Timeline for Why do the 2N2222 and PN2222 avalanche differently?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| May 15, 2022 at 22:13 | comment | added | Vladimir | At my opinion, this is not real avalanche which takes place in collector body at high voltage and is initiated by extracted carriers as at usual BJT operation. This is breakdown junction avalanche like in Zener diodes (historically, Zener studied tunnel breakdown so naming is wrong) and added reverse b-e current (increasing with temperature), slightly amplified by inversed transistor. Breakdown current is very noisy by the way. | |
| S Jul 30, 2018 at 0:37 | history | suggested | adamaero | CC BY-SA 4.0 |
There was a lot of incorrect grammar.
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| Jul 29, 2018 at 21:12 | review | Suggested edits | |||
| S Jul 30, 2018 at 0:37 | |||||
| Sep 24, 2016 at 11:56 | comment | added | Nick_F | Read about Jim Williams pulse generator. It uses a 2N2369 in avalanche mode. I used a similar circuit with 2N3904 transistor (but with a different power supply, that generates 200V and it works). The transistor is not connected backwards (emitter is connected via a 50 Ohm resistor to ground and the base to ground via a 10 kOhm resistor) | |
| Feb 19, 2015 at 16:12 | answer | added | Spehro 'speff' Pefhany | timeline score: 8 | |
| Feb 19, 2015 at 15:55 | comment | added | George Herold | I don't understand the avalanches and then resets itself. If you are above the avalanche voltage then current should be on all the time. Maybe a circuit and /or 'scope shot. | |
| Feb 19, 2015 at 14:15 | comment | added | HKOB | To be honest, maybe I don't know what I'm talking about. I have done a bit of googling, and it could be that it is avalanching since you connected it in reverse. I would suggest you try to connect the base like in other typical avalanche transistor circuits though, just with collector-emitter swapped like you were trying (not the typical way), unless you have a higher voltage available (then try the typical way). | |
| Feb 19, 2015 at 13:43 | comment | added | Dehbop | yeah... the 2N2222 is an old component... probably just noise... but it's too regular though... | |
| Feb 19, 2015 at 13:29 | comment | added | HKOB | That doesn't sound like an avalanche effect. To get that you need actively reverse bias a PN junction. According to the 2N2222 datasheet that should happen around -5V for the base-emitter voltage and 30+ for the other. So what you are seeing is more likely noise being amplified. For the rest you should perhaps explain better how you actually want this to work like. | |
| Feb 19, 2015 at 11:51 | history | edited | Dehbop | CC BY-SA 3.0 |
added 142 characters in body
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| Feb 19, 2015 at 11:25 | history | asked | Dehbop | CC BY-SA 3.0 |