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| TL431 linear power supply |
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| Kleinstein:
A larger value for R17 is likely a good idea. About half the values of R8 (feedback from the input) could be a good start. 1 µF for C1 would be really slow and only a start. The shown 2.2 nF seem to be in a reasonable range, when looking at simulations from IMO. One should also keep in mind that the loop gain would change with the feedback divider. |
| not1xor1:
--- Quote from: imo on December 27, 2018, 08:39:54 pm ---Here is the latest LTspiceXVII, and with the latest Bordodynov library (LTspiceXVII_2018Dec21.zip). Below the TL431s offerings.. PS: tried with several TL431 models and got similar results as above.. And the library is here, for the latest download go to "Additional links :" --- End quote --- OK, but what really matters is to know which kind of TL431 library you got. The one I'm using clearly states: Model Type: Transient and AC. The one you're using might be a coarser model... might it not? :wtf: (OK... I'm downloading the huge zip and will check that myself later :D ) |
| iMo:
Here with the 2n2 (C4 in my simulation) and R4 from 100-16k. For 25V/5A pulses and 3V/5A pulses. For 3V the R4s>=1k in order the simulation works "reasonably fast" (PS:With Behavioral model TL431A it simulates fine from 100ohm up). With 25V the R4s>400ohm make more ringing. |
| iMo:
--- Quote from: not1xor1 on December 28, 2018, 10:05:21 am ---(OK... I'm downloading the huge zip and will check that myself later :D ) --- End quote --- A good move :-+ Be careful with the installation of the Library. You have to replace the 2 folders (examples, lib) in: C:\Users\..user..\Documents\LTspiceXVII\ PS: make backup of your own models/parts. Do not touch folders in: C:\Program Files\LTC\LTspiceXVII\ After the start LTspice will reindex the new Library. |
| not1xor1:
--- Quote from: imo on December 28, 2018, 10:40:34 am --- --- Quote from: not1xor1 on December 28, 2018, 10:05:21 am ---(OK... I'm downloading the huge zip and will check that myself later :D ) --- End quote --- A good move :-+ Be careful with the installation of the Library. You have to replace the 2 folders (examples, lib) in: C:\Users\..user..\Documents\LTspiceXVII\ PS: make backup of your own models/parts. Do not touch folders in: C:\Program Files\LTC\LTspiceXVII\ After the start LTspice will reindex the new Library. --- End quote --- I already did that in past, but I prefer to add just the models I need. BTW I use my own paths and just add them to the search path in LTspice settings. In any case I see that there are 4 different TL431 models which added to the one I've been using so far are 5. No wonder the same circuit may produce so different results... ;D I guess the only way to know which one works better is to build a few different real circuits and compare the results. |
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