You can do this with HTML meta tags, insert them in <head>
:
With time interval of 10 secs in each, in your case:
From panel1.php to panel2.php, insert the following meta tag in panel1.php:
<meta http-equiv="refresh" content="10;URL=painel2.php">
From panel2.php to panel3.php, enter the following meta tag in panel2.php:
<meta http-equiv="refresh" content="10;URL=painel3.php">
From panel3.php back to panel1.php, insert the following meta tag in panel3.php:
<meta http-equiv="refresh" content="10;URL=painel1.php">
This will be looping