Switch log (WAL)

Hello,

I'm new to the list, and I'm intereted in PostgreSQL replication (using WAL)
As I didn't find any script to do that, I make mine, that seems to work.

However, I wonder how can I "switch WAL logs", in order to have the standby
database not too much late.
The database actually generates few logs, and I would like one WAL to be
generated once per hour.

How Can I do that ?

Regards,