View attachment 146170
Hello everyone
I am learning Zener diode but something stuck in my mind
Is this zener diode called a wave shaper? So is this information true or false?
Hi,
As many others here have said, it's probably a voltage regulator. However, when you ask this kind of question we probably want to stay a little more general. The question then becomes, in keeping with the most general interpretation what do we call a circuit that has a zener diode. If I draw a single zener diode with nothing else, what kind of circuit is that.
The only thing I can think of at the moment is that a zener limits the voltage across it, so the circuit must be limiting something, and that would be voltage, current, or power. That I guess would mean that if we want to stay completely general, we'd have to call it a "limiting circuit". The problem then is we have to ask what it is limiting.
It's funny because when we see an op amp in the circuit we might call it an "op amp circuit". We might not yet attribute any specific function to it, but we usually do. For example, "amplifier circuit", and then we may get even more specific, "voltage amplifier circuit", "current amplifier circuit", "photo diode amplifier circuit", etc.
Ok, so what do we call the zener diode circuit then? Oh wait, I just called it a "zener diode circuit", didn't I. I guess that's the general name then. Now we'd like to get more specific, if possible.
This is where we have to try to interpret the intent of the designer, which is sometimes hard to do. In this circuit we see a 20 volt DC source being applied to a resistor and zener diode, with a resistor across the zener which is the load.
Now we know that zener diodes can be used as voltage regulators, voltage references, and clipping circuits, at the least. So, how does any of that fit with this schematic.
Since we see circuits like this all the time and they are usually referred to as "voltage regulators", I think we can call this a voltage regulator circuit. If we saw a wave generator on the input then I think it would be more appropriate to call it a wave shaping circuit or a clipping circuit. Clipping circuit might have an AC sine wave input and the output is clipped on both peaks to be limited to some required output value. A wave shaping circuit is usually more elaborate, but we could call it that. There's no wave generator on the input though, so that's an indication that it is not a wave shaper circuit or clipping circuit. That does not mean it cannot be used for that, but since the author of the drawing did not show a wave generator, it is much more likely that it is just a voltage regulator or perhaps a voltage reference.
Did the person drawing the diagram make a mistake, maybe it was not the circuit designer that copied the design into a digital form that could be displayed on a computer. If that's the case, then we could argue that no circuit on the web is what it appears to be and so we could never conclude anything about any circuit we see on the web, ever. Although that is a very general outlook, it's not the right stance to take. We believe what we see until we have reason to believe otherwise.
All this means to me that the intent is to show a voltage regulator or voltage reference, and not a wave shaper or clipping circuit. If this is not the original intent, that's too bad, but it would not be our fault for interpreting it wrong because logically that's the most reasonable interpretation.
It does however make sense to question this a little bit because of the rather 'large' 220 Ohm series resistor, but then again some regulator circuits do not have to deal with higher currents. For example, this could be a 9v battery eliminator circuit, and that would most likely not have to put out much current (45ma max with 20v min input) because circuits that run with a regular 9v battery usually do not have to put out much current, and the circuit might be meant to be used with a 15v wall wart (with higher low-current output voltage).
I also want to make it clear that this does not mean it cannot be used for another purpose such as a wave shaper or clipping circuit, but then again you could use this as a paper weight if you really wanted to