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If you're like me, you know how annoying it is to use up 9V batteries on your guitar effect pedals. Its wasteful, and brand name 9V's are almost $9 for a two-pack. If you forget to turn off your pedals you've thrown away big bucks. Its an extreme waste of money when you can build your own power supply for only about $25.
The power supply I designed and built delivers steady, regulated 12 volts, 9 volts and 5 volts all at the same time. Each voltage has two outlets, but they can be "daisy chained" with a custom cable to connect many more pedals.
The styling is an homage to the old days of vacuum tubes, when components generated so much heat they needed to be on the outside of the casing instead of inside. I used some gigantic capacitors that I thought would look cool, other than that they are major overkill.
In this Instructable I am going to assume that you know some basic electronic skills and know what I am talking about when I say capacitor, resistor, LED, transformer, AC and DC, etc. There are lots of introductory electronics Instructables and soldering Instructables you can check out if you'd like to gain a better understanding of basic electronic principles and components.
The power supply I designed and built delivers steady, regulated 12 volts, 9 volts and 5 volts all at the same time. Each voltage has two outlets, but they can be "daisy chained" with a custom cable to connect many more pedals.
The styling is an homage to the old days of vacuum tubes, when components generated so much heat they needed to be on the outside of the casing instead of inside. I used some gigantic capacitors that I thought would look cool, other than that they are major overkill.
In this Instructable I am going to assume that you know some basic electronic skills and know what I am talking about when I say capacitor, resistor, LED, transformer, AC and DC, etc. There are lots of introductory electronics Instructables and soldering Instructables you can check out if you'd like to gain a better understanding of basic electronic principles and components.
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Signing UpStep 1Planning and Schematic
The first thing to do is design the circuit. Many guitar pedals and stompboxes have 9V DC power jacks on the back (if your's doesn't and you're feeling ambitious, you can add your own) which we will use to power them instead of the 9V internal battery clip.
The schematic I designed can be modified for whatever voltages you would like. For example, if you don't have any 5V pedals, you can just swap the 5V power regulator for a 9V regulator, and now you'll have double the 9V power.
The schematic uses a simple power supply circuit converting AC to pulsating DC, smoothing it with capacitors and running it through voltage regulators for fixed DC outputs.
Here is a higher resolution version of the schematic if you can't read the one below very easily:
http://img.photobucket.com/albums/v321/mattthegamer463/Schematic.png
The schematic I designed can be modified for whatever voltages you would like. For example, if you don't have any 5V pedals, you can just swap the 5V power regulator for a 9V regulator, and now you'll have double the 9V power.
The schematic uses a simple power supply circuit converting AC to pulsating DC, smoothing it with capacitors and running it through voltage regulators for fixed DC outputs.
Here is a higher resolution version of the schematic if you can't read the one below very easily:
http://img.photobucket.com/albums/v321/mattthegamer463/Schematic.png
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Do you hear the noise out of your amplifier or is the noise from the power supply itself?
My design its simpler ,I did it for only 9v,. It took me a long time to understand the diagram and I more than triple check everything and did everything very carefully
One question..How many pedals can I daisy chain from a single line(or whatever its called)? , for what is worth I used the smaller 100uF capacitors and currently Im daisy chainning 2 overdrives and a wah without any problems, but I may add another one or two pedals more in the short future.
Thanks
Heres a couple of pics
Txs for the tutorial man, it's great
To find the current through the LED take the supply voltage minus the LED voltage (5V - 2.1V = 2.9V) and divide it by the resistance in series with the LED (220 ohm) and you get 13mA. A little lower than the maximum for the LED which is 20mA so it will work fine and not be too bright.
Thank you very much for the prompt reply.
If you have 30 pedals, 100mA each, thats 3A @ 9V you need, which is 27 watts.
So find a 9V 3A transformer, build a bridge rectifier circuit, add capacitors, put some large heatsinks on three 1A 7809 regulators, add output capacitors, and wire the output of each regulator to 10 output connectors.
It is very easy to scale the design almost indefinitely. You may want to consider a switch mode power supply to produce less heat and have higher efficiency.
I have a EHX Germanium OD witch is a little sensitive to power supplies.
It hums like crazy with "one spots" and daisy chains.It likes only batteries but i don't,for obvious reasons!
Do you suggest i build this?
Thanks!
A regulated supply made with a 7809, they are accurate to a few mV, more accurate than a battery, and with one small cap and several large caps on the output they are extremely stable output, virtually no ripple.
In short, yes I think it will work for you.
-how do I add a negative voltage in it?
-it has 6 outputs right? so does each output have one regulator? if it only uses one regulator for the nine volts, how many outputs could I create?
-what is the use of the switch for?
-and would it be possible to run both 9v and 12v together?
This has six outputs, each regulator has 2 output connectors. Depending on your current demands for each pedal, you can calculate how many pedals you can connect to each regulator. Each regulator can deliver 1A, the average pedal will not exceed 100mA, you can probably put up to 10 pedals on a single regulator. If you exceed the available current, the regulator will automatically shut down if it exceeds its maximum temperature.
The switch is to turn it on and off...
I'm not sure what you mean about 9V and 12V together, but you can put different voltage regulators in place anywhere you want. You can have any kind of voltage that the 78xx series regulators offer. Just don't connect different voltage regulator's output pins together or they'll be damaged. For example, plugging a cable from one output directly into another output. Bad.
what I meant about using 9v and 12v together is, is it possible to have two voltage outputs, both 9 and 12 in one circuit?