Hz overload

Since the 9v battery supply is quickly used up, I am using a ac
battery eliminator/wall wart to run the Led timer.

Although the eliminator provides the needed 12v to 15 v, it also
changes the 50 hz dramatically to several khz.

The khz output from the eliminator completely upsets the 555 timer
input, so there is no timing available from with the circuit.

I tried a 1000uF with several diodes placed at the eliminator=92s
output, but there is hardly any production of dc.

Thanks.

Steve.