12v wallwort modify to 4.2v?

I am trying to set flex drives as precise as possible, but I do not have a bench supply. I do however have a 12v wallwort, is there any way I can modify that to simulate a fully charged li on battery?

Have you even measured the voltage coming out of your wall wart, or just read the label on it, 99% of the time they are unregulated so you could have 19 volts coming out with no load.
I suggest you buy the correct equipment if your going to do what your trying to do, mass produce lasers for sale, this is where a little experience would help you a great deal.
but I forgot you already know everything, your 16 :crackup:

how about going to goodwill and buying a 5 volt wall wart instead of trying to modify the one you have. if you are smart and look for a regulated one you may just come up with one that will only put out 5 volts.

Peace All...

Yes it is 12v I have measured it, it was an external sata powersupply, that I snipped the ends off.

I have bought the correct equipment, but it is in the mail and I want to set some flex drives.


Oh and don't worry, I have plenty of experience, and referring to "mass produce" not even close, I am just planning to offer a cheap DIY laser kit for all of the people wanting to learn, and the drivers I am planning on using will be pre set. So there is no need for me to even use a bench supply.

About the being 16 part, age has nothing to do with it, I'm sure you know a lot more then I do about some things, and I know a lot more then you about others.

I don't see why you must feel to always be an ass to me.

Flaminpyro said:

Have you even measured the voltage coming out of your wall wart, or just read the label on it, 99% of the time they are unregulated so you could have 19 volts coming out with no load.
I suggest you buy the correct equipment if your going to do what your trying to do, mass produce lasers for sale, this is where a little experience would help you a great deal.
but I forgot you already know everything, your 16 :crackup:

how about going to goodwill and buying a 5 volt wall wart instead of trying to modify the one you have. if you are smart and look for a regulated one you may just come up with one that will only put out 5 volts.

Peace All...

Click to expand...

Good day,

Simplest way I can think off to get your voltage, is for you to re-view the LM317's datasheet (im bringing that IC up since its so common).

This is one of the most common way to get adjustable voltages via a linear approach, and there are many ICs and circuits that can do so.. endless to list, so for the LM series:

set it up as a simple voltage regulator rather then the current version we see so often here.

if you want some better regulation, you can add a zener diode appropriate to the required voltage and a larger filter capacitor (1000uF or so) on the final output side of your 4.2V. (should spike suppression be nessasary, add a fast responce TVS with a clamping voltage of 5V or so, and a RC snubber)

Alternitavly, this is a linear approach were all that excess voltage is wasted as heat, so you can build a buck-converter and bring down the voltage this way, but parts and simplicty wise, LM317/350/338 is a good approach.
(I like the 338's because of thier 5A capability and same voltage referance)

Partially to the topic of LM338s... they come in two packages. the metal can and TO-220. Disecting one I found out that thier dies are identical and the TO-220 LM338 seems to be a good approach IMO.. a nice hermatic seal and a copper tab, not to mention a the same die.

Below a picture of the LM338 die in a steel can, if your going with those ICs, get the TO-220 ones.



Versatile little buggers. ...... For a linear

helps out a little?

Perception is everything in your case it must be your perception of me as I have tried to help you many times but you come off as knowing it all already ( you even just stated that, I have plenty of experience you said) so I refer to your inexperience of being 16, so please inform us all of just what it is you know a lot more of than me, is it something that was invented after I stopped learning things :thinking: :crackup:

If you had bought the correct equipment you would have a nice bench power supply and not be asking how you can hack a wall wart to do the job of the proper equipment !

Age has every thing to do with it and when you get a little bit older MAYBE you will grasp that fact that you have become a little bit smarter, I'm not sure you already seem to know everything.

tell me can I make a 12volt wall wart look like a 5 volt wall wart ?

I gave you some good advice and all you can say is why do you have to be a ass to me, wake up and smell the coffee kid !

I'm done with trying to help you, you only see what you want to see
and say screw all the rest...

bhwollen said:

Yes it is 12v I have measured it, it was an external sata powersupply, that I snipped the ends off.

I have bought the correct equipment, but it is in the mail and I want to set some flex drives.

Oh and don't worry, I have plenty of experience, and referring to "mass produce" not even close, I am just planning to offer a cheap DIY laser kit for all of the people wanting to learn, and the drivers I am planning on using will be pre set. So there is no need for me to even use a bench supply.

About the being 16 part, age has nothing to do with it, I'm sure you know a lot more then I do about some things, and I know a lot more then you about others.

I don't see why you must feel to always be an ass to me.

Click to expand...

Whats this have anything to do with the OP's question and topic?