5 volt regulated Supply

Gramps

Senior Member
Looking for a source for a really decent plug-in regulated 5 volt power supply.
Among the thousands of online parts, what are you long time "Picaxe Pros" using?
A unit that would work for breadboarding and for finished projects would be great. We don't mind paying a little more for quality!
Thanks, Gramps
 

datasmith

Member
I bought this from Amazon.com for $40 US last September.
It's just 2AMPS but plenty to breadboard micro-controller circuits and small servos, etc...
Adjustable voltages include 5V, 9V and 12V among others. This allows me to test my voltage regulated circuit designs against 9V and 12V battery sources.
Small, light weight, clean voltages. It's been working great for me non stop since I purchased it.

Battery Eliminator, Power Supply, AC to DC, 3V, 5V, 6V, 7.5V, 9V, 12V Outputs 2 AMPS Regulated DC Power
 

lbenson

Senior Member
really decent plug-in regulated 5 volt power supply
Not sure exactly what you mean. If a bench power supply, then the suggestions above could work for you, especially Tex's if you are looking for current limiting to guard against shorts in your projects under development (though you're not likely to want to use it for finished projects, especially if they're going somewhere away from your bench).

If you're just looking for a beefy plug-in, I've been using these 2A and 3A units:

 

techElder

Well-known member
and for finished projects
Sorry, Gramps, I didn't retain that you were looking for something to go with a finished project.

Like you said, there are so many options. Lance's choices certainly would be adequate for normal low-power projects and development. I also use something like that to power my development platform (AXE091.)

You definately should look for "universal" input voltage (90 - 240 vac) units, although the mechanically different plug situation is usually ignored.

Mostly, I'm building to fit protected 18650 batteries with external recharge capability. Seems like the way to go anymore.
 

datasmith

Member
Sorry Gramps. I read that wrong too. Didn't catch that you wanted a supply that you could also use for the finished project. I'm typically building battery powered projects. Ergo I need a true bench supply.
 

lbenson

Senior Member
Do you have a source for these batteries and their charger.?
Here is my latest for nearly-off-the-shelf 18650 battery holder + charger UPS:
18650 UPS A.jpg
Like this: https://www.aliexpress.com/item/4000200690185.html
As this youtube video points out, there's an issue with these if used as a ups--if mains gives out and the battery is discharged, if the load upon the return of power exceeds a certain, small, amount, the battery won't recharge:
I've made the following modifications to get around this problem:
18650 UPS B.jpg
As shown in the photo, I cut the trace between the ON switch pin and the V+ pin on the usb connector and replaced that link with a 1N5818 schottky diode. I ran a wire from the diode near the USB charging connector (S1) to another 1N5818 also connected to the same V+ pin. If mains comes back on when the battery has been discharged, the mains current supplies the load with (assuming not too great a load current) a surplus to charge the battery.

This has not been extensively tested, but seems to work--if your circuit can tolerate a little less than 5V because of the schottky diode voltage drop.

These are available with slots for 1, 2, or 4 18650 batteries. Runtime on battery will depend on how good your batteries are. I always use "protected" 18650 batteries because of various dangers. These battery chargers are also quoted as having battery protection. Belts and suspenders, I hope.
 
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hippy

Technical Support
Staff member
Looking for a source for a really decent plug-in regulated 5 volt power supply.
It really depends on what you consider "decent" and what specification you are after. For 5V would normally just grab a USB power supply, measure it's voltage to check it's within a reasonable 5V spec.

USB supplies are usually very generic so hard to recommend any particular brand but anything which is used with high-quality kit should be good enough. The higher the current rating the more likely it is to have a better spec in my experience.

For breadboard work I would always use a bench supply which has current limiting.
 

rq3

Senior Member
I've purchased this model (have two for various reasons) and have been satisfied with their load carrying and sufficient regulation. I don't remember who recommended them to me, but someone did.

I bought the 30A version.

I see that they are not in stock, but perhaps you could do a search for other suppliers.

30V 10A/5A DC Power Supply Adjustable Variable Dual LED Display Digital Lab Test
I have what looks like a 30 volt/30 amp (1 KW) supply from the same manufacturer. They're all over the Bay, and seem to work pretty well. I've had mine for years, and it works well for everything from micro-welding, to massive lead-acid battery charging, to electroplating and anodizing, to powering breadboards. But it's one of dozens of supplies I drag out (or build) and use depending upon need.

A few provisos:
1) Mine is VERY slow to respond. It even takes several seconds to power on, or off.
2) The constant current, or current limiting, function, is very strange. Not unusable, but takes getting used to. As a retired Hewlett-Packard engineer, I find having to short the supply to set the current limit a tad...odd. It's reliable and functional, but...odd. Regulation is acceptable. Not great, but acceptable. Noise is good per wideband oscilloscope, and stability is good.

Overall, a good supply for the price. Just be aware that you will get what you pay for.
 
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lbenson

Senior Member
How much would you limit the current when working with micros?
Whether to even bother depends to a considerable degree on how much you have to lose. You can burn out a picaxe pin with, say, 30mA. Or a chip with 100mA or less. If you're attached to $50 worth of gear which can be damaged, perhaps you'd choose to use a current-limiting supply. If you're controlling industrial equipment, surely you should.

To answer the question of how much, you'd need to know how much of a load you would expect given the conditions you want to operate under.
 

Gramps

Senior Member
I have a 28X2 That has a burned-out pin. We were quite surprised to see that the rest of the chip still works fine. Don't know how we did it. Would running a load on a pin without a resistor smoke it?
 

lbenson

Senior Member
Would running a load on a pin without a resistor smoke it?
If you change "would" to "could", the answer would be "Yes, definitely".
Suggestions are to not exceed about 20mA on a picaxe pin (maybe 25mA--exact limits to be found in the microchip documentation). If you hook an LED to a picaxe pin without a resistor, you will probably burn out the pin.
 

Gramps

Senior Member
So basically use a wall wart for finished projects and a current limiting power supply for experimental work. That makes good sense.
 

Gramps

Senior Member
This from Adafruit Industries
LED
current use is measured in milliamps (mA). As a rule of thumb, we usually use 20 mA as a guideline for a single LED at full brightness, and each color “pixel” contains three LEDs (one each for red, green and blue), for a total of 60 mA per pixel when displaying white at full brightness.
 

premelec

Senior Member
FWIW I use a module from Ebay that shows and regulates voltage and current - a step down regulator that I attached to an old HP 30V 2A switching
power unit - the module I got was 30v 4 amp so can produce up to 12v 4 amps out - for example of the units I'm referring to: search DC32V/3A DPS3003 DP20V2A 30V5A on Ebay - I'll try post a photo later. I also use a 2x lithium battery case with switch - use only one battery and put an up converter in the other battery compartment to set 5 to 12 volts out [with 1 amp battery over discharge protection bit].
 
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Hemi345

Senior Member
FWIW I use a module from Ebay that shows and regulates voltage and current - a step down regulator that I attached to an old HP 30V 2A switching
power unit - the module I got was 30v 2 amp so can produce up to 12v 4 amps out - for example of the units I'm referring to: search DC32V/3A DPS3003 DP20V2A 30V5A on Ebay - I'll try post a photo later. I also use a 2x lithium battery case with switch - use only one battery and put an up converter in the other battery compartment to set 5 to 12 volts out [with 1 amp battery over discharge protection bit].
I was just going to ask if anyone had used one of the RD Tech power supplies and could recommend one. I've had the DPH5005 in my Ebay cart for months. They have software that allows you to use your computer to connect to it with either USB or bluetooth (if you get a model that has those capabilities). I downloaded and played around with the software a while back and it seemed very mature and easy to use. The logging function is pretty neat too. I'll order one when I finish up some of these other non-electronic projects hopefully in the next couple months 🙃
 

premelec

Senior Member
@Hemi345 - that looks similar to what I've been using - just at higher price - there are units as low as $12 if you can deal with monocolor screen... The one 'complaint' I have is that I forget just how the multi function clicks work - not simple twist of knobs like on my old Heathkit CC CV supply - anyhow once you get used to how the controls work they work quite well and the unit is pretty efficient... the higher current ones may need a fan on their heat sinks running higher currents - I bought my 35v 4 a unit for about $25. a few years ago.
 
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