5V Power supply

zo0o0om

Hey I am working on a project involving the basic stamp 2 chip, and my problem is how to get power running through it. I was thinking of getting a phone charger with a 5V output, cutting the wire and attaching it to the breadboard. Would that work? or are there any other simple/cheap solutions?

Thanks

allanlane5

Go to Radio Shack and pick up a $5 to $10 "6-volt DC" adapter. http://www.radioshack.com/product/index.jsp?productId=2049709

Oh, excuse me, it's $1.47.· Get the right "Adapta-plug" with it -- 2.1 mm inner, 5.5 mm outer.

And hook it up "Center Positive".

Post Edited (allanlane5) : 8/5/2010 6:17:08 PM GMT

zo0o0om

sweet, and how would I connect that to a breadboard?

allanlane5

Worst case, you could simply push a couple of wires in where the "adapta-plug" would plug in, plug the other end of the wires into your bread-board. You'd have to power everything from the BS2's regulator output on "Vdd", which isn't a very good idea, but can work for very small circuits.

A better approach: you can use one of these http://www.kronosrobotics.com/xcart/product.php?productid=16304&cat=287&page=1 for $15 or so, along with the wall-wart -- that will give you an amp of current at 5 volts for your BS2 AND your other circuits.

Oh, and if you use the KronosRobotics unit, you'll need a 7.5 volt wall-wart -- the 7805 regulator used on it won't put out 5 volts with a 6 volt supply.

Franklin

This would give you 3.3, 5, or an adjustable voltage

http://www.adafruit.com/index.php?main_page=product_info&cPath=38&products_id=184&zenid=a84f4dd5e6753457ce1613ef616db7e4

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- Stephen

zo0o0om

Bah, I'm kind of on a tight budget and I found a bunch of old phone chargers that all say they output 5V on them. That is why I was hoping maybe there was some way to just use one of those somehow by stripping the wires and maybe throwing in a resistor or something.

Franklin

That's OK to do if you don't mind blowing up a stamp or two in the process. The stamp can be powered from 6 to 12v if I remember but your other parts can't be powered by the stamp if they draw too much power.

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- Stephen

Martin_H

If you are using the stamp to control servo's then they can probably handle the output of the AC adapter. So power the middle pin from the adapter output. But IC's need regulated power and as Franklin points out the current supplied by the stamps on board regulator is only enough for the stamp. So if you want to control something like a PING))) you'll need an additional voltage regulator.

Eventually you'll want to spring for one of those nifty breadboard regulators as they are really handy. When you do that you may find that a 5V adapter isn't enough. This is because the voltage regulator is not 100% efficient and you need higher than 5V to supply 5V.

Spiral_72

zo0o0om wrote: »

Bah, I'm kind of on a tight budget and I found a bunch of old phone chargers that all say they output 5V on them. That is why I was hoping maybe there was some way to just use one of those somehow by stripping the wires and maybe throwing in a resistor or something.

You might be ok if you have a charger for one of the really old phones.... that used NiCd or NiMh.... I don't know that I'd try to use a recent charger for Lithium cells.

Do you have any old printers? Scanners? Maybe a cordless phone wall-wart??

I'd use batteries before I used the newer cell charger.

zo0o0om

Ok Thanks for all the help guys, let me see if i got all the info you gave me. I should be fine as long as the voltage and current doesn't exceed the maximum aloud voltage/current for any of the parts on my breadboard right? The chip has a regulator on it in the VDD so I don't have to worry about that, but lets say the adapter is supplying 6V when the IR detector only needs 5V, it might start overheating and eventually burn out? What if I just powered it shortly, I am only trying to receive codes from a TV remote, and then I will be changing the circuit to output those same codes with an IR emitter.

I am new to electronics and programming, I would be completely lost right now without this forum. Help is appreciated

Phil Pilgrim (PhiPi)

If the wall wart is labeled "charger" do not use it as a power supply! Typically, these units have zero filtering, and a unit spec'd as 5V can have peak voltage outputs as high as 15V or more.

-Phil

Peter KG6LSE

but then again MOST 5V "CELL"phone chargers are SMPS with a USB ( hence 5v) output and are Very stable ...
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My rule with ANY PSU . Is to use a O scope . or at least a meter on the AC scale to see the AC ripple and how bad it is .
And in DC mode I put a load on it just to see if its regulated well and what not .

When ever I get a walWart I wil do theas tests and label my bricks with there Real Specs .

If its heavy and what not its Iron core and may or may not be Regulated . if is light like a cell charger then is most likely a SMPS and will have good regulation for the most part ..
Most of those cell chargers are not the active part of the charge loop . the IC IN the Phone is doing the chargecontroll .

EDIT looking at the spare charger for my palm Centro , its a flat 5 V
the only down side is its .5A so for a ton of servos it may glitch in to protection mode . .

Peter KG6LSE

Mike Green

It really depends on the parts involved and their power requirements. Some parts will only accept power supply voltages up to 5.5V. Some parts will work with voltages up to 6V. For some parts (like LEDs) only the current flowing through the device is important and something external (like a resistor) is used to limit the current. You have to know your devices ... read the datasheet and look for maximum operating voltage. If you exceed that, your device may be toast!