Alan:
Your transtor is saturating when on, and it is probably very slow to come
out of saturation. Try putting a diode from base to collector; that will
keep it from saturating. Here is the circuit:
This trick is called a 'baker clamp' for some reason. The diode prevents the
transistor from saturating, thereby increasing the speed at which it can
turn off. This circuit probably won't do more than a few MHz, but you never
know.
Re: Simple transistor NOT gate ... Try putting a diode from base to collector; ... keep it from saturating.... This trick is called a 'baker clamp' for some reason. ... This circuit probably won't do more than a few MHz, ... (sci.electronics.basics)
Re: Current flows from collector to base of PNP transistor ... The idea is that I can connect any convenient supply to the +/- connections on the left and a maximum current determined by the 0.3 ohm resistor will flow into the batteries.... I was surprised, however, to find that when no power source is connected the batteries seem to discharge into the circuit at about 20 mA. ... In my understanding of how transistors work, if the emitter is floating then no current can be flowing between the base and the emitter, and if no current is flowing between the base and the emitter than no current should be flowing between the collector and anywhere. ... Thing is, the base-collector junction is a diode as well, pointing the opposite way. ... (sci.electronics.design)
Re: Current flows from collector to base of PNP transistor ... The idea is that I can connect any convenient supply to the +/- connections on the left and a maximum current determined by the 0.3 ohm resistor will flow into the batteries.... I was surprised, however, to find that when no power source is connected the batteries seem to discharge into the circuit at about 20 mA. ... In my understanding of how transistors work, if the emitter is floating then no current can be flowing between the base and the emitter, and if no current is flowing between the base and the emitter than no current should be flowing between the collector and anywhere. ... Thing is, the base-collector junction is a diode as well, pointing the opposite way. ... (sci.electronics.design)
Re: Transistor base as a diode ... a diode where the base is also short circuited to the collector. ... The most common case that comes to mind is a current mirror circuit,... is as the OP mentioning a transistor with its CB ... (sci.electronics.components)
Re: Transistor base as a diode ... rating equal to the maximum collector current of the transistor, and tends to have a nice low forward voltage drop at moderate currents compared with average small signal diodes, but the main advantage is that the diode characteristics match the characteristics of other transistors in the circuit so you get good current mirrors, especially if both are part of the same IC, so good thermal tracking and in some situations low distortion or little error over a wide operating current range. ... (sci.electronics.components)
