Re: Oscillators in LTspice

On Fri, 18 Oct 2024 12:38:42 -0400, bitrex <user@example.net> wrote:

On 10/18/2024 12:33 PM, Cursitor Doom wrote:

Gentlemen,
 
I've never spiced an oscillator AFAICR. Do they self-start in spice
simulators (LT in particular)? IOW, did Mike Engleheart build something
into the engine which generates wideband 'background' noise, particularly
at 'power up' as it were? I'm assuming there must be some such mechanism
and if there is, it must be present by default for all schematics one
attempts to simulate and not just oscillators?

>
They can be a PITA to start in LTSpice, like this old chestnut really
doesn't want to run at all IME in LT but is fine on a breadboard:
>
<https://upload.wikimedia.org/wikipedia/en/thumb/8/83/Forrest_Mims_hand_drawn_circuit_1983.jpg/220px-Forrest_Mims_hand_drawn_circuit_1983.jpg>

A classic blunder: turn the trimpot all the way and blow out the
transistor.

Turnoff can zener the base too, for long-term damage.

How many mistakes can be made in a circuit that has N components?