I wouldn't rely on this though unless using non-symmetric component values.
QuoteI wouldn't rely on this though unless using non-symmetric component values.It is impossible to have anything other than non-symmetrical component values. All components even if marked with the same value have a tolerance. Even when you try and match components you only acheave a match to a certain number of places. Even if you acheave the impossibility of exactly the same component values, transistors with the same gain, and so on. They are physically diffrent things in physically different places. There willbe differences.
Initial power-upWhen the circuit is first powered up, neither transistor will be switched on. However, this means that at this stage they will both have high base voltages and therefore a tendency to switch on, and inevitable slight asymmetries will mean that one of the transistors is first to switch on. This will quickly put the circuit into one of the above states, and oscillation will ensue. In practice, oscillation always occurs for practical values of R and C.
plus they mentioned random circuit noise
The name for all oscillators of this sort is "relaxation oscillator" -
this is a cross coupled bistable oscillator.
Different side of the pond definitions here I think.
I hate resistor colour codes.
The first multivibrator circuit I created on a breadboard was based on the 7404. I later built the 2 transistor version. I always thought was backwards... but the simplicity of the 7404 circuit made understanding the transistor circuit easier. I really wish I could find a book I had in 1978 that described discrete transistor astable multivibrators. monostable multivibrators, bistable multivibrators and Schmitt Triggers.