Servo crashing arduino?

I've been working on a project that requires multiple power-consuming components (RTC, 7-segment LED, and servo. For more info see Anniversary Gift - Programming Questions - Arduino Forum)

When I add the servo, however, the led-display begins flickering and eventually goes blank. I'm using a classic 9-volt battery as a power source, and I only need the servo to work once at a specific time after which it will have no use. I've tried connecting the servo to its own power source (another 9V), but that doesn't work for some reason. I also know little to nothing about how to wire capacitors. Any suggestions on how to make it work?

I'm using a classic 9-volt battery

. Well, don't do that. Use four AAs or AAAs, and put the smoke detector battery back where it belongs.

Do not attempt to power motors and servos from the 5V output of the Arduino. It is best to use a completely separate motor supply (not a smoke detector battery), and connect the grounds.

  1. Servos need 1A or more peak current, need a power supply capable of that.
  2. small 9V batteries are good to upto 100mA or so before fading fast - no good for motors (though
    rechargables are higher current)
  3. servos and motors should not be run from the 5V logic supply rail, they put spikes, noise onto
    their supply and can crowbar it if the supply isn't upto the peak current demand - use separate supply
    for motor/servos