purchasing new power supply

Hi,

I am looking into purchasing a power supply. I came across two that I am interested in. The only difference is the amps - one is 3Amp and the other is 5amp. The cost difference is about $60.00. Being a 2 amp difference is there a significant difference. Here are the two I am looking into.

HY3003D-3 30V 3A Dual Output, 4 Digital Displays Variable Regulated DC Power Supply Extra independent 5 V/3A output


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HY3005D-3 Dual Output, 30V 5A, 4 LCD Digital Display Variable Regulated DC Power Supply, extra independent 5V/3A output


I am not sure which one to purchase, like I mentioned, basically the one difference is one is 3A and the other is 5A. Does the 2A difference really make a significant different for using on testing your basic circuit boards.

Any input would be greatly appreicated, or you suggest another brand/type I would welcome any input.

Thank you in advance your response.

Lisa

2Electrified said:

. . .not sure which one to purchase
Does the 2A difference really make a significant different for using on testing your basic circuit boards.
Any input would be greatly appreicated, or you suggest another brand/type I would welcome any input.

Click to expand...

For each supply, plot the current on the Y-axis and the price on the X-axis. The third data point is zero amps for zero dollars.

If you collect data (from catalogs or the Internet) for several supplies around 3A to 5A you may see a flattening of the curve. This area probably shows where the manufacturers are competing for the best $/amp ratio, other things being equal.
Then you can see how your two supplies are doing in the whole scheme of things. Outliers
https://www.google.com/search?hl=en&q=define+outliers&aq=2&oq=define:+outlier
should be disregarded or researched.

Hopefully a bargain will jump out at you.
Then the question of quality becomes important. I doubt that any manufacturer is going to tell you the real value of his calculated MTBF.
https://www.google.com/search?hl=en&q=define+MTBF&btnG=Search

I used this method on another forum to rate two cordless electric drills for watts/$, A-h/$ and torque/$. Some parameters came within pennies (~1%) of each other and I do not believe this was a coincidence.
Then another poster came up with a drill that beat the pants off of the first two using the same system and was also rated a Consumer's "Best Buy".

2Electrified said:

I am not sure which one to purchase, like I mentioned, basically the one difference is one is 3A and the other is 5A. Does the 2A difference really make a significant different for using on testing your basic circuit boards.

Click to expand...

For most electronic testing 3A should be adequate. Typical circuit boards generally take no more than a few watts. You would likely only need more current if you were testing something involving motors, such as stepper or servo devices, or high power amplifiers.

The 3A should serve you well for general electronics projects.

I agree, 3 amps is enough. I do many of my projects with either a 1A or 2A supply and find that these cover about 80% of the work. Another 18% of the time I need to work on something for a car, like for example a two-way radio, and in these cases I use a 13.6V 20A supply or a GelCell (12V battery) just for that purpose. The remaining 2% need something that these won't supply.

I have the HY5003 which is a 3 amp 60v power supply, and it works great!!!

Get adjustable current limit; it's great for tracking down shorts without smoking stuff or using up fuses.

For more flexibility, you can also build your own modular supplies with a diode bridge/heatsink, a Variac, rheostats, etc., with dirt cheap parts from Hosfelt.com or Allelectronics.