[Assignment] Need to make the most simple circuit possible

[UberStrike88]

Hi,

Well I got a assignment today from school and the most simple circuit possible and it should be useful with the part you get.
Some got a easy chip like the 7805 and some got something harder. Anyway I got this chip:
AZ431-A
http://www.diodes.com/datasheets/AZ431A.pdf
So yeah it's a three-terminal adjustable shunt regulator 
Well I have no idea it should be easy useful and it needs to be with the least parts you can use.
Anyone got any idea?
(yes we may ask around on forums )

Regards,

[AndyC_772]

What's wrong with the application circuits in the data sheet?

[JacquesBBB]

Just look to the datasheet and make the first example. It looks perfect to me. To understand it, as well as the
functional diagram  schematic on page 4 is a perfect training for you.

[UberStrike88]

Just look to the datasheet and make the first example. It looks perfect to me. To understand it, as well as the
functional diagram  schematic on page 4 is a perfect training for you.

Okay will try to make it although they don't specify what rating the resistors need to be

[AndyC_772]

No, but you can work that out for yourself. You know what the input voltage, output voltage and reference voltage are. Pick sensible currents, and then you can work out the power dissipation in each component from Ohm's law.

[JacquesBBB]

As an exercise, you can demonstrate the formula of the first example : Vout = (1+ R1/R2) Vref. You will see that it does not depends
on R3 nor on Vin.

If you want to get benefit from this simple example, you will  have to determine also the minimum and max values for Vin, and as said by Andy, the required specifications of the resistors.

[Seekonk]

Love the 431, an op amp and a voltage reference.  Voltage detectors,relay driver, time delay, even turn it into an audio amplifier.

[Refrigerator]

Make the first example circuit and add a darlington transistor and you got yourself a little voltage regulator. Simple as that.

[AG6QR]

Another idea:  Add a single transistor, use the current source example from the data sheet, and you've got a constant current LED driver.  It can drive an LED with 20mA (or whatever you design it for) over a wide range of input voltages.