DC Power Supply that says 12-24V

[DW1961]

I was thinking about getting one of these units for other than critical use, such as testing LED strips, and so on. However, for instance, my laptop (not that I would use a cheap unit on my laptop) says the power supply in 19V. So, how does a 12-24 V PSU regulate its voltage to make sure it isn't over volting? For instance, if I want to test a 12V LED strip, and the PSU says 12-24V?

[bob91343]

It's unclear what you are asking.  I know of no power supply that puts out 12-24 Volts.  It's one or the other, or something else, but it can't be two voltages at once.

[SmokedComponent]

It could mean it has an adjustment trimpot.
But you never know with the cheapies...

[DW1961]

It just says 12-24V. See, that's what I was thinking that it's either one voltage or another, unless it can automatically switch or something. The output on teh supply says 19.5V, so I think the description is misleading.

If you plug that into a 12V device, isn't it going to over volt it? Or would the devices circuitry keep it from doing that, and just take the volts it needs?

[radiolistener]

It looks like unregulated power supply. It can produce different voltage and your equipment will be burned out if you connect it to such PSU.


I recommend to buy KORAD KA3005D. It allows to setup output voltage from 0V to 30V and current from 0A to 5A precisely, also it has OCP and OVP protection.

[tooki]

I was thinking about getting one of these units for other than critical use, such as testing LED strips, and so on. However, for instance, my laptop (not that I would use a cheap unit on my laptop) says the power supply in 19V. So, how does a 12-24 V PSU regulate its voltage to make sure it isn't over volting? For instance, if I want to test a 12V LED strip, and the PSU says 12-24V?

Please post a link to or photo of the power supply in question.

It's unclear what you are asking.  I know of no power supply that puts out 12-24 Volts.  It's one or the other, or something else, but it can't be two voltages at once.

Unless it’s a constant-current power supply, which are common for LED lighting. Those adjust the voltage to maintain a constant current.

[DW1961]

Here it is:

https://www.amazon.com/dp/B07X8PV2JZ

[james_s]

Maybe the interchangeable tips contain a resistor or other component used tell the PSU which tip is installed and thus which voltage to select? I'm not a fan of these "universal" solutions but it could be handy to have one around.

[Twoflower]

The product description at Amazon is optimized to generate as many hits as possible. If the product description tries to cover the whole data sheet usually I don't trust the description at all.

Here's the manufacturers page of the supply: http://www.tenwei.com/index.php?c=product&a=detail&id=40
(Data sheet; site is in Chinese but PDF is english: https://pan.baidu.com/s/1S89Ys5zwFEh6hwqD1oBdLQ)

● Dimension: 105*60*26mm
● Input Voltage: AC 100–240V
● Output Voltage: 19V/3.42A
● Output Power: 65W
● AC Input Cable 1000mm
● DC Power Output Cable 1000mm
● Storage Temperature -40 to 40° C • Operating Temperature 0 to 40° C
● Built-In Circuit Protection Overvoltage, under voltage, over temperature

So nothing 12-24V. It's fixed 19V

[james_s]

Well that's annoying. Sometimes Amazon really drops the ball in how items get listed. If there's too much noise in the search I sometimes end up just shopping somewhere else.

[TimFox]

Was that Amazon listing for the device itself, or did Amazon sort the universe of devices into bins, and this one fell into "12 to 24" with its 19 V rating?
Elsewhere, I complained about several DC power supplies listed on eBay as "250 V, 1 A", which was actually the rating of the line fuse on the nameplate.

[radiolistener]

Here it is:

https://www.amazon.com/dp/B07X8PV2JZ

according to product description it has 19.5V
12-24V is probably possible customized version which needed to ask seller to sell customized item

[DW1961]

It's just a 19V 65 watt PSU. I hope when people plug this into their devices, the device itself has it's own voltage regulation.

Ohhhh gawwwwd. It never ends.

[tooki]

They’re just banking on the fact that pretty much all modern high-tech gadgets use lots of internal regulation. (Consider that in a laptop, outside of the power supply/battery charging infrastructure, the only component that doesn’t use 5V or less is the LCD backlight.)