This script for a chatbot give chatters a +voice when they type, as they say 15 minutes nothing the +voice get removed automatic.

on *:TEXT:*:#: { 
    if ($me ison $chan)  { 
    if ($regex($nick(#,$nick).pnick,/(!|~|&|@|%)/)) { halt }
    if ( power isin $1- ) || (Nickname isin $nick) { halt }
    else {
    set %devoicechan $chan
    mode # +v $nick
    timerdevoice. [ $+ [ $nick ] ] $+ . [ $+ [ $chan ] ] 1 900 mode # -v %devoice. $+ $nick | unset %devoice. $+ $nick
    }
  }
}

on *:nick: { if $me ison %devoicechan && $newnick isvoice $v2 {
    timerdevoice. [ $+ [ $v1 ] ] 1 900 .mode $v2 -v $v1
  }
}

on *:ACTION:*:#:  { 
    if ($me ison $chan)  { 
    if ($regex($nick(#,$nick).pnick,/(!|~|&|@|%)/)) { halt }
    if ( power isin $1- ) { halt }
    else {
    set %devoicechan $chan
    mode # +v $nick
    timerdevoice. [ $+ [ $nick ] ] $+ . [ $+ [ $chan ] ] 1 900 mode # -v %devoice. $+ $nick | unset %devoice. $+ $nick
    }
  }
}