Hello guys,
I don't entirely get the purpose of C4 in this circuit. Correct me if I'm wrong, but does it supply the collector-emitter current through the PNP transistor when the 555 output is low?
If the output of the 555 ic is on for just as long as it is off, (50%duty cycle), and C4 charged fully, with still some time to spare when pin 3 is high (in other words, if it took the capacitor for example 0.1 seconds to charge, and the output is high for 0.5 seconds), wouldn't that mean that when the output is low, the PNP transistor will conduct the stored charge for 0.1 seconds (and for the remaining 0.4 seconds, there will be no current through the PNP collector-emitter) before the NPN turns back on?
OR is there some kind of play between the capacitor and the transformer primary? Inductor--Capacitor circuits
Also,
I have come to realize that the bjt astable multivibrator doesn't exactly oscillate at the frequency calculated from the formula f=1/1.4RC (practically). This was in my other post (bjt astable multivibrator oscillating frequency?). I was wondering which is more reliable (maintains frequency with changes in variables i.e. temperature, loading...). Is it the 555 timer IC or the bjt astable multivibrator.
I plan on using one of them for the driver circuit of an inverter.
Appreciate your time.
I don't entirely get the purpose of C4 in this circuit. Correct me if I'm wrong, but does it supply the collector-emitter current through the PNP transistor when the 555 output is low?
If the output of the 555 ic is on for just as long as it is off, (50%duty cycle), and C4 charged fully, with still some time to spare when pin 3 is high (in other words, if it took the capacitor for example 0.1 seconds to charge, and the output is high for 0.5 seconds), wouldn't that mean that when the output is low, the PNP transistor will conduct the stored charge for 0.1 seconds (and for the remaining 0.4 seconds, there will be no current through the PNP collector-emitter) before the NPN turns back on?
OR is there some kind of play between the capacitor and the transformer primary? Inductor--Capacitor circuits
Also,
I have come to realize that the bjt astable multivibrator doesn't exactly oscillate at the frequency calculated from the formula f=1/1.4RC (practically). This was in my other post (bjt astable multivibrator oscillating frequency?). I was wondering which is more reliable (maintains frequency with changes in variables i.e. temperature, loading...). Is it the 555 timer IC or the bjt astable multivibrator.
I plan on using one of them for the driver circuit of an inverter.
Appreciate your time.