{{fa>pencil?32}}
The following circuit depicts a simple voltage reference circuit. There, a Z-diode provides a constant output voltage $U_\rm L$ on the load - despite a fluctuating input voltage $U_\rm S$ from the source. \\
The following quantities shall to be used:
* Source voltage $U_{\rm S}=7.0 ... 13.0~\rm V$ (e.g. via sinusoidal input voltage with $f = 50 ~\rm Hz$),
* series resistor $R_{\rm V}=1.0~\rm k\Omega $
* load resistor $R_{\rm L}= 10~\rm k\Omega $
* Z-diode $D_\rm Z$ as $\rm BZX84C6V2$ ($U_\rm Z = 6.2 ~\rm V$)
{{drawio>circuit_design:diagram1.svg}}
An ideal Z-diode would be assumed to hold the breakdown voltage $U_\rm Z$ at all reverse currents $I_\rm S$. \\
This is to be checked for the real diode.
- Model the circuit in Tina TI and insert a picture of the circuit.
- Compare the progression of $U_\rm L$ to $U_\rm S$. In particular, measure the maximum and minimum values of $U_\rm L$.
- Change the load resistance to $R_\rm L=1.0~\rm k\Omega $ and perform the same comparison of $U_\rm L$ to $U_\rm S$ again.
- How can the difference be explained?