Absolutely, it is called a crowbar circuit and it is very simple. It requires an SCR, zener diode, resistor, and small capacitor. The capacitor in combination with the resistor prevent triggering due to noise.
http://electronicsinfoline.com/pin/12440/
http://axotron.se/index_en.php?page=26
Usually a fuse is included before the crowbar circuit so that when the crowbar triggers, the fuse blows for safety.
What value should I need to adjust for a 19.5V power brick and +- V range that should be given to this power brick? Is there anything than a fuse that I can use so that I don't need to change it every time if it blows? Something that would reset itself once going back to normal condition.
The crowbar should never activate under normal circumstances so using a fuse is not a big deal.
The crowbar voltage is set by the zener voltage plus the forward voltage drop of the SCR's gate which is roughly 0.6 volts. To protect the output of a 19 volt supply, you want to be at least 10% high or even better 20% high so a 22 or 24 zener diode would be suitable.
The value of the resistor across the SCR gate is set to sink leakage current from the zener diode and should be as low as possible. Typically the gate voltage divided by the zener test current is a good value. The zener test current at about 24 volts is about 5 millamps so 0.6V/5mA=120 Ohms.
Put a 0.01uF capacitor across the SCR gate in parallel with the resistor to prevent false triggering from noise.
Some designs include a low value resistor in series with the gate to prevent the SCR from being damaged if the zener diode shorts but in that case, I just replace the SCR when I replace the zener diode anyway.