azambon
commented
9 months ago I had a chance to take a look at the code.
Here is a possible issue, in that the check volts[N_OUT] > volts[N_VIN]/2 does not seem to take into account that the ground pin may be connected to something other than ground. It should probably become something like volts[N_OUT] > (volts[N_VIN]+groundVolts)/2 after moving the definition of groundVolts to the top of the method.
Same here, where the volts[N_CTL]/2 expression does not yield the expected value in case of a non-ground negative supply. (volts[N_CTL]+groundVolts)/2 should fix it, I think.
I cannot find anything else in that file, so perhaps fixing those two items would be enough?
pfalstad
Hello, I stumbled across an issue with the 555 timer. It appears that if the "gnd" pin is connected to a voltage other than 0V, the component misbehaves. Take a look at the attached screenshot: two oscillators with the exact same components and configuration and both supplied with 5V, except that one uses a positive supply (+5V / 0V) while the other uses a negative supply (0V / -5V). One would expect both circuits to behave the same, except that the voltage levels are shifted. Instead the one with negative voltages does weird things.
(please ignore the long "off" time in the upper scope trace at the beginning. I was messing around with the time step setting).
Here's the link to that sample circuit: https://www.falstad.com/circuit/circuitjs.html?ctz=CQAgjCAMB0l3EwwEx2QdnQZkgDmQGwCcR6IArJBRVeQKYC0YYAUGAeSACxe4ip8uBLvzwgC3aCWklK8BCwDG3diCxYJXVVzhRwjMmGjZIwyFlyR0RJDzIwFAJxUT2VLROQ69XdPBYA7hTont7kRMj83pCBFBFRtPFuULHhkcnkYOkEVDFBmdm0WeAhKfnFyR7gOSnOVV7uqjgiVEhwsTx8DS4JZdy8apAiVc19I0M96hJ5kxr9fFN95DxqBHzLw7ozG9y6VTq5sTaRByDouJuHQcerfDenM+cii7hNc48XgyJPau+xrxJRj9RjMAb0ft0Ys4Id5gRNWv4grhLNUqD9kqCUclka1SjMiDVsViaviat0Ca0SUcVuSydEWNDPskYbluH52spgXMfg99AwyFxoFlwuYQgQwBpkEROA5IKx2JwwQIQLgsJFldMWBp1qUMJEcl10JFDtqQEQaUazbrLYcAEo9SqqLJ8VlhPS5aDkFj29E1dHIF0+VnBz3enqnfZq927aMer0+z6nHlR11UBgy92hgD2gxVQaI63E0Ba-FzWBYOawEEDWSl7ikMlk8gQUFgLaokSrahYQA