Author Topic: How to raise 5V DC to 9V DC - use USB chargers/batterybanks with Guitar pedals?  (Read 2511 times)

Offline Skylark

I got a Korg Guitar pedal that along with the typical power sources guitar pedals use - 9V battery/9V DC power in from power brick/wall wart it also has USB-in for power. Amazing!! So now instead of needing R500 BOSS rip-off power supplies(or cheapies) I can use any decent quality USB wall charger or Powerbank for battery power, what a revelation.

So now I need some way of converting 5V to 9V to use with my other guitar pedals that use the typical BOSS style 9V DC input.
 
Is there anything like this avail in SA(shipping from US is crazy):
https://www.adafruit.com/products/2777
USB to 2.1mm DC Booster Cable - 9V


This may be an affordable option at R86, does the design/parts look decent enough?:
http://www.aliexpress.com/store/product/DC-DC-USB-5V-to-9-16V-Step-Up-Boost-Converter-Voltage-inverters-Module-Adjustable-Output/1525466_32264776580.html


« Last Edit: March 05, 2016, 11:18:22 PM by Skylark »
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Online Michon

That is cool!

How do these devices create 9V from 5V?  :thinking:
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Offline JimGore

You can easily find a switch mode power supply (SMPS) that will convert 5V DC to 9V DC.  Take a look on the websites of the normal electronics parts suppliers.

Kind Regards,
Ian.

Offline Atom8

If you could start with 9v and reduce it to 5v, these seem rather inexpensive. I have not dealt with the seller or the product, though.
http://www.giga.co.za/ocart/index.php?route=product/product&path=78&product_id=115
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Offline Rick

Search for "5V-9V charge pump" or "5V - 90V boost inverter" on Ebay, or just on the web, returns many results and options.

USB is current limited though, so make sure whatever you are drawing is within the USB socket spec or whatever 5V source you plug it into.


Offline Skylark

Finally found exactly what I was looking for on ebay and only R25:
http://www.ebay.com/itm/USB-DC-5V-to-DC-9V-12V-Step-up-Module-Converter-2-1x5-5mm-Male-Connector-Plus-/401215703430

Nice form factor, voltage booster is all integrated, but also only low current. Rated around 800mA would imagine 500mA would be a better idea of the maximum useable/stable continuous output, that's plenty for what I need though. Trying to find a decent wattage 12V booster now to power a Wireless router off a battery bank, need min 12V 1A.
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Offline ScottulusMaximus

Won't get 12V at 1A out a battery bank, is over 2A at 5V which is above USB standard.
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Offline ingenieus

That is cool!

How do these devices create 9V from 5V?  :thinking:

It is all possible thanks to switched-mode DC-to-DC converters. It stores the input energy and then releases that energy to the output at a different voltage. The storage can be a magnetic field (inductors, transformers) or an electric field (capacitors).

Here is a simple circuit that does exactly more or less what the OP desires.


Offline kubusi

Such a device exists about the size of a 24 pin IC, they can be salvaged off old scrapped PC motherboards and most are marked 5v to 9v, I am not sure as to the available current from them but that information will be found on the Internet. I have a few laying around somewhere which were harvested from old computers. Alternatively  without the trouble of  building up the device just get hold of a wall cockroach as I call them that puts out 9 volts from a stepdown transformer, they should be freely available with current ratings of up to 1 amp.
One point to be aware of the cellphone chargers these days are switchmode and put out a lot of noise that can be picked up by nearby radios and audio systems unless they are adequately shielded
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Offline Skylark

Such a device exists about the size of a 24 pin IC, they can be salvaged off old scrapped PC motherboards and most are marked 5v to 9v, I am not sure as to the available current from them but that information will be found on the Internet. I have a few laying around somewhere which were harvested from old computers. Alternatively  without the trouble of  building up the device just get hold of a wall cockroach as I call them that puts out 9 volts from a stepdown transformer, they should be freely available with current ratings of up to 1 amp.
One point to be aware of the cellphone chargers these days are switchmode and put out a lot of noise that can be picked up by nearby radios and audio systems unless they are adequately shielded
What wattage is the output?
Won't get 12V at 1A out a battery bank, is over 2A at 5V which is above USB standard.
Good Battery banks have at least one 5v 2.1a output, all my Romoss banks have that feature.
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Offline ScottulusMaximus

Good Battery banks have at least one 5v 2.1a output, all my Romoss banks have that feature.

12W at 5V is 2.4A and that's ignoring the inefficiencies of the converter, it's unlikely your router will draw 12W continuously but it's something to look out for.
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Offline Contrabass


Offline Skylark

This will do the trick - and is available locally...

https://www.robotics.org.za/index.php?route=product/product&path=59_387&product_id=535

More info
https://www.pololu.com/product/799
Thanks, I have found plenty of those on eBay for under R50 incl shipping, just have to wait 8-12 weeks, I'm in no rush though so eBay it is for me.
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Offline Skylark

12W at 5V is 2.4A and that's ignoring the inefficiencies of the converter, it's unlikely your router will draw 12W continuously but it's something to look out for.
That is true, was thinking of switching off wifi completely or just run one of the wireless bands to reduce the current needed.

Or I may build a higher output voltage DIY 18650 bank to supply the router, will first test  with the 2.1a bank and see how it goes.
Music is in the Mind