Quote:
Originally Posted by tangerine911S
rick: So that 10.7v wont be constant? That sucks, I thought I was all set. Can you suggest how I might get a constant voltage >9v out of this 12v battery?
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Radio Shack will have one of these
LM317 Got to page 7 to set the output voltage. Note that on page 3 it says VI – VO Input-to-output differential voltage is a minimum of 3.
Now add up how much current will be drawn by all the devices. Multiply that number by the
Highest expected input votage minus the voltage you set the regulator to. This wil give you Watts dissipated in the junction of the pass transistor. Multiply that number by 19 deg C per Watt (theta junction to ambient for TO-220) and make sure that number is less than 150 deg C.
Edit: and since you now have measured the current divide the amp-hour capacity of the battery by that number and see how long it will work.
Edit: Edit: If you register with TI and put your buisness name along with engineer or student somewhere in the application they will send you samples of almost anything you need.