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Subject: Starting RockBox from the hard drive with connected power supply...

Starting RockBox from the hard drive with connected power supply...

From: Kay Bruns <>
Date: Wed, 22 Oct 2003 18:32:40 +0200

I bought a JukeBox Recorder 20 two weeks ago to use it as a CD changer replacement.

I'm one of these guys that cannot flash RoxBox because the flash is a SST37VF020
that is not in circuit programmable.

So I searched for a solution to turn on my AJB with the external power plug
without starting the original charging routine.

The solution is pretty simple:
-Pulse the power for a few milliseconds to turn the AJB on
-switch the external power off until the hard drive is turned
 on (after something around 12 seconds) and
-switch the external power on again and keep it on.

In the Attachment you see a picture of a little circuit that I designed
to do the power on job. I currently use it in my car.

 -The FET can be any enhancement p channel FET with at least 1.5A drain current.
 -The two transistors should have a hfe of min. 100.
 -The 1M resistor may need to be changed if the 100uF ElKo has too much leakage current.
  You'll see that if the power ON time is too long. I've got 330K instead in my car.
 -My AJB handles the 13.6V as charging power very well. It does not get any hotter
  than with the original charger. If you worry about the health of your AJB anyway you
  can still put a 10V power supply before my circuit.

Have fun.

Kay Bruns

PS: I'm offline until 2003-10-31. If you have questions I'll answer them after.

Received on 2003-10-22

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