.PS
cct_init

# Usual defs...
qrt=dimen_/4;
hlf=dimen_/2;
dim=dimen_;

{gap(up_ 2*dim); llabel(-,V_z,+)}
line right_  
resistor(up_); rlabel(,r_z,)
battery(up_); rlabel(,V_{z0},)
line left_; 

"\tiny ZenerMod " at (dim,-qrt)
.PE