[Mr.PD]

I have spent most of the day searching for information on ac to dc power adapters, know around here as walwarts or wall warts. I have not been able to find much. What do you use to power things like a META 42 that is using 2 nine volt batteries? How important is a "regulated" unit? For that matter what is the difference between regulated and not, other than 30 bucks? The Elpac brand was mentioned, and I found their website. The only retailer mentioned here for Elpac was Digikey, but they don't carry the 18 volt model I was looking at. Heck, do I even need the full 18 volts?

So many questions......................

 

[john_jcb]

I am unfamiliar with the META's voltage needs but you definitely want a regulated supply. Simply put a regulated supply puts out a constant voltage no matter what the load or supply voltage fluctuations (within limits).

 

[puppyslugg]

You should be able to use a regulated 24v ps.

 

[qwerty870]

Your voltage reqirements depend on the opamp your are using. The Burr Brown OPA-627 deffinitely needs 18V or higher. While the OPA134 needs at least 5. More power is usually better than less until you get to about 27V. To find about the max power tolerated by your opamp you would have to look at a spec sheet. In unregulated power supplies the output voltage varies with the input. In a regulated power supply the outputted voltage is more stable. I would strongly reccomend a regulated power supply.

 

[puppyslugg]

Hi Mr.PD ,

A 24v reg. psu would give you +-12v which would be ok for most opamps, including the ad8610. If your meta uses ad843, opa627/37, etc., you can use a higher voltage psu. Not much more than 30v.

I think the 24v psu would give more flexibility in terms of opamp swapping. Particularly, if your meta doesn't use the ad8610 and you want to try them in the future. If opamp swapping isn't in the cards, then you should pick a psu optimal for the opamps in your meta now.

 

[Mr.PD]

op amp ad843kn. Also I may be using 8620 in the future.
I am sorry I didn't add that in the begining.

Thanks Puppyslug where is a good place to buy a walwart?

 

[JMT]

Try looking here: Elpac

 

[Mr.PD]

To order from Elpac is a minimum of $250.
How about Newark? They sure have a hell of a mark up for Elpac products.

 

[puppyslugg]

Digikey carries elpac's.

 

[JMT]

Allied Electronics has them as well.

Check them out here.