How can I make coins respawn in my game?

I am trying to make a coin system in my game. It's working except that I just want the coins to respawn. What can I add to this script to make the coins respawn after a certain time limit?

local db = true
script.Parent.Touched:connect(function(hit)
    if hit.Parent:FindFirstChild("Humanoid") ~= nil then
        if db == true then
            db = false
            script.Parent.Transparency = 1
            local player = game.Players:GetPlayerFromCharacter(hit.Parent)
            player.leaderstats.Coins.Value = player.leaderstats.Coins.Value + 10
            script.Sound:Play()
        end
    end 
end)