Let's Make Robots!

A mini relay like chip?


Here is the setup, I need a picaxe to "push" 2 buttons when it receives a high digital input. 
I will be using a picaxe08M and will have 2 digital inputs(2 buttons) and to digital outputs to triger the relay.
 
I need somethink like a relay but much smaller, about the same size a the picaxe chip.
 
It only need to handle 5V.
 
Anybody know of something that would do the job ? 

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Thanks for all the help ! 
 
It turns out that connecting the switch to my Picaxe through a 330 resistor and setting the pin to LOW was all that I needed to trigger it !
 
I will try to integrate this idea in to my current robot so that reseting and starting the micro controller will be that little bit simpler.  
 
A ULN 2003 is perfect for relays and is rated at 500MA. It has 7 drivers and cheap  too.   I would send the data sheet but don't know how. Google it.
Does a switching transistor act as a relay?

They both can be considered switches, the only difference is the way you switch them on and some other things. For example, a transistor is much faster than a relay, but the relay is better if used for high voltage applications.

In vince's case, they both would do the job, so going for transistors makes it cheaper. 

I don't get the big deal....If 20 mA are enough then just to as ignoblenome suggested, if you want some more then a BJT transistor does the job, that's all!

It seems to me like he want a curcuit that is normally closed, but when 5v is applied to the controll input a connection is established between to other connectors. So he wants the funtionality of a relay, but in a smaller package...

 

I suggest you read up on the links posted by ignoblegnome and deside what kind of voltages you plan to use.

I only need to be able to control 2 buttons so only need 2 digital outputs.

The circuit I am making is to push the start and reset button on a C-Stamp (more complicated version of a Picaxe), the C-stamp runs on 5V and for a button to be “pushed” it need to be connected to G trough a resistor.      

The Picaxe digital outputs can sink or source about 20 mA each. Couldn't you just run the outputs through a 330 ohm resistor and set them to logic low to trigger the start and reset buttons on the C-Stamp?  Since you are just driving 5V logic, there should be no need for additional current drivers like a Darlington or external transistor.

Am I missing something?

It just sounds too simple if you know what i meen, but I will still try.

Just finished puting the circuit together, wil lhave to wite a simple code and test it. 

It wouldn't really work exactly like a relay, but it would be able to crank higher voltages with just a digital out ...