Timeline for Negative Inputs For Diode Transistor Logic
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
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| S May 18, 2021 at 21:19 | history | suggested | Glorfindel | CC BY-SA 4.0 |
broken image fixed (click 'Inline' or 'Side-by-side' to see the difference; image retrieved via Wayback Machine); for more info, see https://git.io/JqCQN
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| May 18, 2021 at 13:22 | review | Suggested edits | |||
| S May 18, 2021 at 21:19 | |||||
| Mar 9, 2017 at 18:04 | history | edited | CommunityBot |
replaced http://people.seas.harvard.edu/ with https://people.seas.harvard.edu/
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| Apr 28, 2015 at 7:56 | comment | added | Russell McMahon♦ | .... so Q1 is on. | If either of Da or Db cathodes are grounded then R1 bottom is clamped to 1 diode dropabove ground and Q1_b gets no drive so Q1 is off so Q1C is pulled up[ by Rc (which is higher than usual at 4V for LED drive) and LED is on. IF you can understand how it works then all about it soon becomes (almost) obvious.|| Reverse Da and Db. Remove R1 and place it from Q1_b to ground (becoming R2 which you have not supplied). Add a resistor < R2 ) say 1K in series with 2 unnamed diodes . Now you have a gate with LED ON when inputs are low and OFF when either input is high. | Then ... | |
| Apr 28, 2015 at 7:49 | comment | added | Russell McMahon♦ | You need to learn to understand how the circuit actually works and not work by "rote". This really really is a very easy circuit to inderstand once you grasp the basic principles. Omce you do you will be easily able to not only see how it works but to build other versions. Presumably "The LED" (unshown) is from collector to ground. || The transistor is turned on by current via R1 providing base drive., When Q1 (the transistor) is on then Q1_c is low and LED is off. If Da and Db float as whoen then R1 top is at 4V and current flows via R1, 2 series diodes (one on breadboard) to Q1_b .... | |
| Apr 28, 2015 at 2:33 | answer | added | Tom Carpenter | timeline score: 1 | |
| Apr 28, 2015 at 2:04 | history | edited | JohnnyStarr | CC BY-SA 3.0 |
Had to post different logic circuit
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| Apr 28, 2015 at 1:59 | history | asked | JohnnyStarr | CC BY-SA 3.0 |