Convert files to specific encoding with converting, solving special chars

ConvertToEncoding.ps1

Add-Type -typedef @"
  public class EncodingHelper
    {
        public static System.Text.Encoding GetEncoding(string file)
        {
            System.Text.Encoding encoding;
            using (var reader = new System.IO.StreamReader(file, System.Text.Encoding.Default, true))
            {
                reader.Peek(); // you need this!
                encoding = reader.CurrentEncoding;
            }
            return encoding;
        }
        public static string ConvertFile(string file, System.Text.Encoding targetEncoding)
        {
            var sourceContent = System.IO.File.ReadAllBytes(file);
            var sourceEncoding = GetEncoding(file);
            return targetEncoding.GetString(System.Text.Encoding.Convert(sourceEncoding, targetEncoding, sourceContent));
        }
    }
"@
function Convert-To-Encoding([String]$filter, [System.Text.Encoding]$encoding) {
    Get-ChildItem -Recurse -Filter $filter | ForEach-Object {
        write-host "Start.... $($_.FullName)"
        $data = [EncodingHelper]::ConvertFile($_.FullName, $encoding)
        write-host "Converted..."
        [System.IO.File]::WriteAllLines($_.FullName, $data, $encoding)
        write-host "Written... "
    }
}

Usage. run file, then use method "Convert-To-Encoding" provide filter and encoding