Converter? A electrical component question...
 

Here's the thing... I am making something.

I have taken apart an old dancing cactus that responds to sound. I want to use the sound sensor and the circut board (3volts) to run a 9volt motor and two 110volt appliances. I can't use a 9volt bnattery to run the board, as it would undoubtedly fry it. (or would it?)

I have the second half of the thing set up, relays, wiring, the whole bit. It all works perfectly when switched with a 9volt battery. The problem is that the activation signal has to come from the circut board, which runs of 2 AA batteries, 3volts, whereas all of the relays that I can find need a minimum of 9volts to operate the electromagnetic coil.

So here's my question...

Can I buy a 3volt to 9volt converter? or are there 3vot relays out there? If so, where?!?!?! I've been looking all over the web for this stuff, I think the problem is that I just don't know where to look. I've been to my local RadioShack a number of times, and they've hooked me up with all the other stuff I need, but they don't deal with 3volt doo-hickeys!

Maybe I'm barking up the wrong tree...

Oh well. thanks in advance.

GO HERE FOR RELAYS there are pretty fair priced

once you set up one small relay to trigger the 9 volt motor you can then use that relay to trigger a bigger 12v actuated relay (they will operate on as low as 9 volts) that really can switch a 110v motor or two..depending on size...

Okay, thanks a bunch!

That site gave me a couple of options, ordering now...

You can use resistors to tap different DC voltages from one DC source (i.e., the battery).

www.digikey.com is your friend. Type in relays into the search function, pick what kind of relay you need, and then it'll set up a parametric search function. Go from there.

If you want to know how to bump up a voltage from 3 volts to something bigger, you can but together a boost switching power supply circuit, but then again that may be too advanced for you. I did a Google search on boost voltage regulators and here's the
link for that, if you are so inclined to want to learn more.

It looks like you got the help you need, but for future reference:

1. You can use a resistor network to lower the voltage of a source. However, you need to be careful of the amount of current that you need at the lower voltage.

2. You can also buy DC-DC converters that can either step up or step down a DC voltage.

3. Instead of a relay, you may also be able to use a transistor. They can switch large amounts of current with a low input voltage and very low input current.