Electronics / USB power issues - can someone help?

[carlsim]

Hi all,

 

I am trying to power my Chocolate Plus MIDI pedal and GP-5 via the power supply I already have - standard 9v daisy chaining thingy. Not expensive but I don't have loads of pedals. Chocolates will only run via 5V USB so I need to adapt my 9v PSU to run a 5V supply.

 

A friend of mine (also read this online) told me a standard USB cigarette lighter will work with 9V so try one of those. I had a spare, took the innards out, fashioned (quite crudely) a 9V supply via a 9V battery and YES! It came alive!

I wanted to double check the output was 5V - so I plugged in an old USB cable, stripped back the wires and measured across the red and black and yep - 5.10 volts. Perfect. It's stepping down the 9V to 5V. Just what it should be doing.

To be sure, i plugged the same stripped cable into my PC which I know powers and charges the Chocolate plus and again the voltmeter reads 5.06 volts.

Connect the chocolate to the PC USB port and everything comes alive. Chocolate charges and powers up and the Valeton GP-5 also comes on.

Connect the same cable to the 9V powered USB and the chocolate will charge but as soon as I plus in the USB host cable to power the valeton, the charge light goes out and the GP-5 it doesn't power up. Is there not enough in a 9V battery supply? Will connecting it to the mains 9V power supply make a difference? 

 

I am at a bit of a loss here - both outputs read the same voltage - one works and one doesn't. Is the battery not man enough to maintain the voltage when the draw is too much? I am going to try it out connected to the 9V power supply but wanted to make sure I wasn't wasting my time before I did so!

 

thanks for any advice guys!

 

Carl.