Backup SQLServer 2008 DataBase using PowerShell

This script will backup all database execept "tempdb", as follow:

try{

[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SMO") | Out-Null
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SmoExtended") | Out-Null
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.ConnectionInfo") | Out-Null
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SmoEnum") | Out-Null

$server = New-Object ("Microsoft.SqlServer.Management.Smo.Server") "(local)"
$backupDirectory = $server.Settings.BackupDirectory
foreach($dbToBackup in $server.Databases)
{
  if($dbToBackup.Name -ne "tempdb")
  {
   Write-Debug "Begin backup database $($dbToBackup)"
   $db = $server.Databases[$dbToBackup.Name]
   $dbName = $db.Name  
   $timestamp = Get-Date -format yyyyMMddHHmmss
   $smoBackup = New-Object ("Microsoft.SqlServer.Management.Smo.Backup")

   $smoBackup.Action = "Database"
   $smoBackup.BackupSetDescription = "Full Backup of " + $dbName
   $smoBackup.BackupSetName = $dbName + " Backup"
   $smoBackup.Database = $dbName
   $smoBackup.MediaDescription = "Disk"
   $smoBackup.Devices.AddDevice($backupDirectory + "\" + $dbName + "_" + $timestamp + ".bak", "File")
   $smoBackup.SqlBackup($server)
  }
}
$directory = Get-ChildItem $backupDirectory
$backupFilesList = $directory | where {$_.extension -eq ".bak"}
$backupFilesList | Format-Table Name, LastWriteTime
}
catch [Exception]
{
throw "Backup database error"+ $_.Exception.message
}
Write-Debug "BackUp database Success..."