Help with Keypad 'Unlock'

[OsirisGuy]

Greetings from the States!

Stumbled upon over here, such a great site. I'm hoping someone could help me with this idea I have.

I want to create a keypad where the correct sequence of number must be pressed to either start a motor or unlock something or light up a light/LED. I currently plan on doing this by having four push buttons in series with capacitors in between. When the first push button is pressed the first capacitor charges and holds. When you press the second push button the charge transfers from the first capacitor to the second. This goes so on for ever how many buttons there are. However on the final push button instead of the charge transferring to another capacitor I would have it connected directly to the motor/LED as if any other switch would be. For the cancel buttons I would wire a few other push buttons in parallel, all connected to all the capacitors so if a 'cancel' button was pushed the capacitor would discharge and the correct code would have to be re-entered.

A couple of other concerns:
I would like the the final push button transfer the voltage from the last capacitor for 1 second, that is have the voltage being applied for at least a second before the capacitor is fully discharged. Would another resistor do that?
Will the voltage transfer from one capacitor to the next?

All I can think of for now. For a little visual aid I included a schematic. Joined lines have dots or blobs. If there is no blob they are not connected. And I'm very new to all this stuff so forgive my mistakes or misinterpretations and what not.

Thanks a lot folks!

[Biffo]

You could not use a keypad on its own to drive a motor- I would have thought- because the current would be too much for the delicate soldier on the pads.

A bit left field- but have you thought of studying the phone system.

A keypad from an old phone could use the DTMF sound tones to control anything you want
from a tone reader and then into some relays.

Have a look at this Stateside supplier for some ideas

http://www.motron.com/cgi-bin/motronsto ... oduct=dtmf

they are experts at making a phone keypad control, and do alsorts of tricks

[OsirisGuy]

I don't think dial tones would be able to help me, or do what I need to do. I mentioned motor just as a generic term, I just need the voltage at the end to be 12v DC, I'm thinking current won't matter too much.

I followed my example, and what I want it to be close too is here. I was browsing around and it seems what I really want is this except I don't want it to activate a solenoid for the door lock pin.

The actual purpose of the lock is to start a vehicle. I've done remote starts on cars, and I know if I can put 12v to the starter wire I should be able to start the car, it's just a matter of the lock working properly. So after punching in a 4 digit password the car starts, is what I'm after.

I'm going to try and get in contact with the second link, perhaps he knows if his schematic will work the same for the starter.