Thanks guys. I appreciate your responses.
Because of your responses to my question, I decided to use a 9 volt battery with a 5 volt regulator for my circuit. It will be a little heavier with the 9v but it shouldn't be a problem. The power is for a reversing and turning circuit for a simple robot.
The circuit will be an object avoidace sensor.
The sensor consists of a simple IR transmitter/receiver, with the output powering an led. The led is inside one end of a black tube, inside the other end of the tube is the sensor for a dark sensing relay circuit.
When the Ir does not see an object, the output is enough to light a white led. The light keeps the relay in the normaly closed position wich in turn keeps the robot moving forward.
When the IR sees an object, the output goes to 0v, the light goes out wich trigers the relay and the robot goes in reverse. When going in reverse, a second motor turns the robot. The IR sensor changes the output at about 5 inches.
I'm in the process of fitting the circuit to the robot. It should work good because I know that the IR and dark sensor work together on a test board.
I'll let you know how the finished robot works out.
Thanks again
Bill