\$$100\$

Testing dollar

Your transformer will convert 120\$V_{ac}\$ to 12\$V_{ac}\$. So you'll need to regulate it to 5\$V_{dc}\$.

\$I_{ce}\$ = \$I_{be}\$ * HFE

\$V_{ceo}\$ \$I_{c}MAX\$

16 - log((5 - 0)/(5 - 4))/log(2) = 13.68
\$16 - \frac{log\frac{(5 - 0)}{(5 - 4)}}{log 2} = 13.68\$

 - \$I_{F_{max}} = 30mA\$
 - \$V_{F_{typ}} = 1.7V\$
 - \$V_{F_{max}} = 2.1V\$
 - \$V_{R_{max}} = 5V\$