Electronics help! Need to make an auto switch delay (for a small bartop project)

[Bender]

I'm working on a little arcade project as a Christmas gift and I'm using an portable DVD player as the screen, but it doesn't automatically switch to the line in, I have to hit a button a few seconds after it turns on to get it to switch. I want to make it so that it will do it automatically, anybody know how to do it?

[Bender]

anyone?

[mountain]

These will give you either a timed off or a timed on, and they are adjustable. So you could get 2 of them and make it work. The first one would set the delay you need, triggering the second one. The second one would be needed to simulate a momentary button press. I am assuming this is what you are trying to do. I have seen them as cheap as $10 before.

Also, I work with some electrical engineers, I can ask them how easy it would be to design a circuit.

[Beley]

You are looking for a "delayed one shot" circuit

check out:
http://www.bowdenshobbycircuits.info/page9.htm

and scroll down to "Generating a Delayed Pulse Using The 555 Timer"

...or you could just buy a "time delay relay" however the ones with at function are usally ~$100

[mountain]

You are looking for a "delayed one shot" circuit

check out:
http://www.bowdenshobbycircuits.info/page9.htm

and scroll down to "Generating a Delayed Pulse Using The 555 Timer"

...or you could just buy a "time delay relay" however the ones with at function are usally ~$100

Nice! Great job Beley. Very interesting projects on that page.

[protokatie]

555 timer! W00T! I have dealt with them before (albeit in a 500 in 1 electronics kit designed for us "kids" to learn about electronics).

I would have suggested a capacitor with a relay myself, but go with the timer IC as it would be cleaner.

[Bender]

555 timer! W00T! I have dealt with them before (albeit in a 500 in 1 electronics kit designed for us "kids" to learn about electronics).

I would have suggested a capacitor with a relay myself, but go with the timer IC as it would be cleaner.

can you explain the capacitor w/ relay and what a timer IC is

assume I'm  a little slow (cause I am)

one other thing, I need this to be as cheap as possible I'm trying to bring the whole project in at $100 or less

[DillonFoulds]

555 timer ICs are somewhat common among electronics hobbyists. Basically, and i mean very basic, it's an IC that you can set up with a trigger or variable resistor to control the internal timing clock. Someone jump in and correct me if I'm wrong here

It's useful for an automated looping event, such as rapid-fire buttons in a game controller.

I'm not 100% on this, memory's a bit hazy. Maybe there was a crystal in place of a variable resistor. I'm fairly certain you can find these ICs in common electronics stores.
RatShack has them, too! Also their big brother the 556, which is essentially 2x 555s in one IC.

[Beley]

Another idea you may want to think about is modifying a standard "LED chaser" or "LED sequencer" you can usually find these as kits. you would only need to cut one connection and add a jumper.  below is a generic circuit and then one showing the changes needed to make it do what you want