e-scale power supply

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spitballer

spitballer

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My e-scale did not come with an a/c power supply and I seem to be going through a lot of 9 volt batteries because the scale takes so long to truly stabilize. It would seem a simple matter of contacting the manufacturer to order an a/c power supply, but I have a feeling it's not quite that simple. I know I've been criticized for being a perfectionist but doesn't any power supply have to be regulated to insure accuracy? I mean, if the a/c adapter is rated at 115 volts and I'm running 110 or 118 or 120, wouldn't that affect accuracy? What is the correct way to handle this? Should I get a regulated a/c power supply to control voltage the adapter, or should I instead get a regulated d/c power supply and connect directly to the unit with the plug? Anyone else ever deal with this problem?
 
which e-scale are you using? Does it have a barrel plug to accept external power? If so, what voltage and amperage does it say it requires?
 
Most wall packs will have a broad range of input voltages, the one next to me is good for 100-240vac. As long as your input is in that range the output will be in it's range 5vdc in my case. So just find one that has a9 volt output and you should be good. You can even go to Walmart and get a wall pack with several interchangeable connectors and selectable output voltage so as to be "universal".
 
While i may not know a ton about reloading (learning quickly thanks to folks help here), i *do* know these small electronics.

On almost all electronics that plug in you should see the input voltage and amperage. Here is an example i found on my desk - a small video device that requires 5v 3a:
20160128_111011-1.jpg

And here is it's matched power cable. Looking on the back you can see the specific output voltage and amps (matches the needed 5v 3a):
20160128_111123-1.jpg

A bit blurry, but i hope this helps you find the right power plug (AC Adapter) to power your scale. Someone mentioned a "universal" AC adapter - those work great if they can select the correct Voltage and amps - then you swap the barrel plugs to fit/match your scale.

I hope this wasn't too remedial and not intended to over simplify. if you give me the model number of the specific scale you have i can look and find the voltage specifications (usually in the detailed specs). Possibly even quickly find a AC adapter on amazon that would work.
 
sl33py pretty much nailed it. Only 2 things to add. If the device requires say 2 amps current, it's ok to use a supply that is rated for more. And even if the plugs mate be very careful to check that the polarity is correct from the power supply. Some devices have protection for reversed polarity and some don't even care, but most will release the magic smoke if you get it wrong.
 
Good catch SCC! I meant to mention the polarity (look at the symbols w/ + and - below output) you can see the negative is the outer barrel, and the positive is the inner post connections. Just make sure those graphics match any power supply you get.

again if you let me know model i can check and recommend if that's helpful?
 
Since the OP did not say if the scale has a AC adapter input jack or not ... I'll pass along an idea for his and for other battery powered devices that use 9 Volt batteries ...

You can buy a battery pigtail for 9 v batteries that has the red & black leades and you can solder the correct wires from an AC adapter to the pigtail ... just make sure to get the +/- in the correct place ...
Connect the pigtail connector in place of the 9v battery ...

You can also take a 9 Volt battery apart and use the connector that is on top of the battery ... there is no acid and junk like batteries of years ago ... inside is several smaller battery cells connected to the connector on top of the battery ... you can simply solder this connector to the AC adapter using the correct +/- wiring order...

My Pact chronograph uses a 9 V battery .... I don't have 110/120 AC near my shooting bench ... 9 v batteries don't last very long when using it ... I made an power pack using AA rechargeable batteries using the 9 v pigtail like above... I can shoot pretty much all I want and not have to worry about my 9 v going dead and giving screwy readings ...
 
Depends. Most electronic devices likely wouldn't operate off the 9 VDC directly anyway. Certainly not the 110-120 VAC, rather have a regulator internal that goes to say 5 volts. There would be a transformer/rectifier from 110 vac to 9vdc minimum. You could always test this yourself with just about any single item, at least for repeatability.

Weigh the same exact thing over and over., If your scale says it's not the same, you know it's not telling the truth.
 
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Never mind. I don't think my information applied to the original posters question
 
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1. I have saved every power supply transformer from every electronic device I have owned over the last 40 years,.
It is rare that I don't have the exact one I need for anything.

2. My older PACT scale uses a simple 9v battery.

3. Or, the 12v 200 mA plug-in power supply that came with it.

4. Seems to make no difference at all in accuracy.

5. I think the 'regulated' power is built into the circuit board on any decent digital scale.

rc
 
Until the original poster comes back with additional information it's hard to answer much of anything. Would be sweet to know exactly what the original poster has because e scale really doesn't say much. :(

Ron
 
On almost all electronics that plug in you should see the input voltage and amperage. Here is an example i found on my desk - a small video device that requires 5v 3a:
Click to expand...


Great photo example!

Any AC to DC generic adapter with the right output will work fine.

I'll add that photo indicates center pin is + as is the case in 95% of these.

Make sure the output says VDC or DC.

Amperage rating can be anythig equal to or above.

Anything within the AC input range will still produce the same DC output.

Make sure the jack on adapters can come in several standard sizes, and may not plug in, even if everything else is right. You can solder a new or different connector if required.

The device (scales) will usually work over a short range of input voltages. (9v battery or 12v adapter for example). It is a digital device, and input voltage within parameters has no effect on accurracy whatsoever. Any AC to DC adapter with correct voltage and amperage rating will be regulated sufficiently to remain well within the device parameters.

Regulated power supplies are usually used for analog purposes when maintaining a precision output is critical, requires filtering, and tends to vary with conditions or spike up and down under load. For example, CB radios would hum, and transmission output would vary with an unregulated power suppy.

I have a whole basket full of saved adapters from a wide array of junked devices. They come in handy, often.
 
jmorris said:
Had to do a search in case "e-scale" was a brand or model...
Click to expand...
Same, took e-scale as a brand name. :) Did a Google and up comes music scales.

Hopefully the original poster will add some information. Sitting here looking at an old RCBS scale I have actually made by PACT. It uses an AC adapter but the AC adapter in this case is little more than a transformer with 120 VAC in and 12V AC out. The DC rectification takes place on the scale's circuit board.

If the original poster has a strictly battery powered scale (no AC adapter) he can likely just get a 9 volt battery snap connector and connect it to a 9 volt wall wart. I doubt a regulated 9 volts is necessary. Just connect the connector Red to negative to simulate a battery. The Male snap being + and female snap being -.

Again, it would be nice to have the data for the scale. All any of us can do is speculate.


Ron
 
First two responses nailed it down - sl33py this would be an Ohaus Scout, no longer in production. I got it on sale from Edmund Scientific years ago to mix aquarium chemistry. and yes, there is a great deal of information on the back but no barrel connector. It also did not come with a complete set of weights.

theothermike - your suggestion was spot on, and in fact I went by radio shack to get a temporary fix and ended up with a permanent solution. The a/c power supply I bought has multiple settings and works very well at 9v - stabilizes more quickly than it did with the battery - a winner!

As usual I overcomplicated this thing and I should have gone to radio shack sooner, but I can remember years ago buying a regulated power supply to use indoors with an automotive CB radio that was as big and complicated as the radio itself and I thought for sure I was going to have to repeat this process. The visit to the Shack turned out great, I got fitted with a barrel connector and even got an education on modern power supply units by the good-looking female manager there! Thanks for all the help guys
 
All the Radio Shacks closed around me ... Amazon works in it's place !!

I saw those "E" scale too ... that was pretty much all that did show up in my searches!
 
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