|
|
| transistor with two emitters | ||
| Author yutcxa Views 41 Posted at 2008/8/26 07:44 [View In Forum] | ||
|
I guess this doesn't require much explanation. I found a transistor drawing where the transistor have two emitters. Actually, I know about drawings where transistors have many emitters.yhnnist yhnnist Question is: Is this realy just a transistor with diodes on its emitter (see atachment)? Would it be possible to replace a multi-emitter transistor with a regular transistor with sereral diodes attached on it's emitter?yhnnist yhnnist My guess is that the multi-emitter transistor (met.) realy have two or more emitters and that it'l work if I replace it as suggested above. I also guess that the met would have a base-emitter voltage of 0,6 volts when saturated (that's what I'm guessing) while the replacement transistor supplied with several diodes must have at least 1.2 volts to get saturated (common knowledge - Vbe Vdiode = 1.2 volts). |
| Reply No. | Replier | Total Replies 4 [View All Replies] [New Reply] | Replied at |
| 1 | edu | transistor with two emitters No you can't replace succesfully a multi-emiter transistor with one emiter transistor OR-ed logic with diodes. The key of this design is egual output impedances on emiters outputs (matched emiter currents on all emiter paths). |
2008/8/26 07:44 |
| 2 | chdd | transistor with two emitters |
2008/8/26 07:44 |
| 3 | htc2498 | transistor with two emitters Reason why I ask is that I have a little private project where I'm trying to assemble some basic logic ports using regular transistors, diodes and resistors. Most of the easy schematics actually works for simple tasks that doesn't require high speed nor low power. Example schematic:
Then I got the idea of replace the multi-emitter transistors as described in first post. The image below shows a simple nand circuit:
And here it would be interesting to know if the dual-emitter transistor could be replaced by a single transistor with two diodes instead - and if it still would be a nand circuit
|
2008/8/26 07:44 |
| 4 | netlgc | transistor with two emitters TTL diodes would need a compensation for the additional voltage drop, LSTTL (actually DTL input with schottky diodes) is more simple. |
2008/8/26 07:44 |
Total Replies 4 Thread Per Page 10
|
|||
