Electronics 2000

Hi everyone, I am very new to electronics and need help with an automated gate. The gate has a magnetic lock which must be disabled prior to the activation of the gate opening ram. The gate motherboard has a 12v output which which gives a signal around half a second before powering up the 220v gate ram but only lasts for about 0.5s. I have bought a simple generic 12v time delay relay which operates opens the 230v contacts to open the gate 5s after the 12v signal. The problem is the motherboard sends the 12v signal for such a short time it is too quick for the time delay relay to react. Is there a way to take a rapid 12v impulse and increase the length of time it is active for. Say, 3-5 seconds or so? Thanks

How about a R S flip-flop circuit that uses the impulse to set the output and a timer, then using the timer to reset it. It is basically a pair of NAND gates. You will probably need to use some a transistor to power a relay which can in turn power the solenoid and timer.
http://www.google.co.uk/imgres?imgurl=h ... AQ&dur=461

Thanks Paul
I will give it a try

Some sort of counter, impulse triggers the counter then it switches off after a few secs.
Something like that.

Tar&stuff.