Battery timer switcher

Hi! I have a simple project I want to make, but I have limited knowledge in electronics component variety, so I hope to get a little bit of advice.

Scenario:
I have arduino and hobby king transmitter connected together. On button being pressed, transmitter sents signal to receiver. Receiver will establish connection between battery/heating wire, keep it connected for 4 seconds, and disconnect them back.

Ok, I've got arduino and transmitter working together. Now as for battery-receiver-heating wire part: what is the best way to make it reliable? Ideally, I want to use only 1 battery source for receiver and heating wire to keep place usage at minimum. Receiver needs 4.2V, heating wire around 9V, so I'll probably end up using 12V battery and 2 voltage regulators.

What is the best way to make system reliable?

I can imagine this draft:

  1. When receiver gets signal, its activates (?) something.
  2. That something(?) connect battery and heating wire together.
  3. Adruino wait 4 seconds.
  4. Signal again, now that (?) something disconnect battery and heating wire.

So, my question is, what that (?) something might be? And...
Is it possible to use only 1 battery? Like, at some point, it will have to power receiver and heating wire through some voltage regulators together - is that reliable? Or I have to stick to 2 separate batteries here?

Thanks!

Do you have any specs on the transmitter /reciever?
The arduino can send a message saying whicherver, but u may need another arduino on the other end to translate that into on or off,
The switching device will depend on the current draw of the heater, a relay setup or transistor can do that
and yes it will be reliable with one battery so long as the battery can handle the draw and that the voltage doesn't drop too far,

Arduino/TX using virtualwire sends signal out

Arduino/RX using virtualwire receives signal.

Some examples
http://www.robotshop.com/433mhz-high-sensitivity-transmitter-receiver-pair-rxa30.html

9V to heating wire to N-channel logic level MOSFET to ground. Arduino drives Gate for 4 seconds, turns back off & waits some more

Make up standalone arduino with switching power supply to run efficiently from 9V.

Thanks a lot for the answer! N-channel logic level MOSFET will do the trick, will google everythign about it now.

Best regards,
K.