The subject has come up several times concerning drive currents. This is something I've puzzled over for a long time, I have the text book examples, but I'm interested in any other ways that might be used to go about this. Here are 3 classic examples.
Figure 1 is a method for boosting a 555 output. It is quick and dirty, and doesn't have any major drawbacks other than switching current that I am aware of.
Figure 2 is somewhat similar, but in analog mode. There is some crossover distortion, but the op amp will try to minimize it to an extent.
Figure 3 is an effort to compensate for the crossover distortion, but has some major problems. The biggest is the possibility of thermal runaway, because it is possible that the transistors will both be conducting at the same time. The second is if the drive required by the transistors exceeds the current flowing through the diodes there will be a cut off of current.
I'm just interest in other possible solutions to this kind of problems. Thanks.
Figure 1 is a method for boosting a 555 output. It is quick and dirty, and doesn't have any major drawbacks other than switching current that I am aware of.
Figure 2 is somewhat similar, but in analog mode. There is some crossover distortion, but the op amp will try to minimize it to an extent.
Figure 3 is an effort to compensate for the crossover distortion, but has some major problems. The biggest is the possibility of thermal runaway, because it is possible that the transistors will both be conducting at the same time. The second is if the drive required by the transistors exceeds the current flowing through the diodes there will be a cut off of current.
I'm just interest in other possible solutions to this kind of problems. Thanks.