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I got two ways to get 5V from the bridge rectifier connected to 110VAC:
Thanks.
I got two ways to get 5V from the bridge rectifier connected to 110VAC:
1-By using the LM7805
2-By using Zener diode 1N4744A
My question is which approach is better?
Thanks.
Just the opposite. The voltage out vs load current of an IC regulator is much flatter than a series resistor-shunt zener regulator.Zener based regulation is usually more precise. IC regulators deliver more current.
Just the opposite. The voltage out vs load current of an IC regulator is much flatter than a series resistor-shunt zener regulator.
Isn't the 4744 a 15V zener, not a 5V one?
Just the opposite. The voltage out vs load current of an IC regulator is much flatter than a series resistor-shunt zener regulator.
You are right. I meant 4733A.
The reason I am posting this question is because my boss saw this zener circuit and said that zener-resistor based regulators are crude, cheap, and they wont handle situations where the AC voltage drops to 100VAC.
For some reason, I used to think that inside the LM7805 there is a Zener!
Thanks guys.
Actually I built two circuits, one using the LM7805, and the other using Zener diode 1N4744A. They both work OK, and I am getting 5VDC.
My question is not about how to get 5VDC; I am just wondering if the LM7805 is a better regulator than the Zener diode 1N4733A. I know the Zener is cheaper, and does not require heat sink.
There might be some Zeners somewhere in there, but only used to set up an internal voltage reference not the output voltage. That is set by a bandgap reference.You are right. I meant 4733A.
For some reason, I used to think that inside the LM7805 there is a Zener!
There are three zeners in there, they just are not used for setting the output voltage.Slightly more than a Zener.