Relay and MOSFET help

hi, i have designed a circuit on chrocodile technology and everything works apart from when i press one of the 'set' switches, the MOSFET blows up and it says something about the drain voltage

any ideas?

same thing happens when using a transistor
here is what i have done:
https://i14.photobucket.com/albums/a316/madmikejt12/eto/untitled5.jpg

it is the MOSFET on the end of the 1st part of the circuit (under the relay coil) that blows up

6v should be fine, so i'm assuming its the lack of a protection diode on the relay coil? When the relay turns off, the inductance of the coil creates a brief high voltage spike which can damage both transistors and MOSFET's. Look here to see an example of how to use the protection diode:



Its rather an unusual symbol for a MOSFET too? Not the one i'm familiar with.

of course.. that did the trick

Thanks alot

**broken link removed** is that something like the symbol you are used to?

Yep, thats the one I use; not always with the circle, but broken lines at least.

yeh...

Thanks for your help anyway.

all i need now is:
Front door opend--->6 second time delay---> if code not entered alarm goes off, if it is entered, alarm is de activated

put them both together, and then my alarm is complete