SoulBay 30W Reverse Polarity Universal AC Adapter Multi Voltage DC Power Supply, with 9pcs Adaptor Tips, Compatible with 3V to 12V Household Electronics, 2Amp Output

This is designed and intended for use as a power supply and not a recharger. It is designed for use with a variety of electronic devices whose power needs fit within the 3-12V at 2.5A range (or lower current levels) and where it can replace or be a permanent alternative to disposable or rechargeable batteries.The "SoulBay 30W Reverse Polarity Universal AC Adapter Multi Voltage DC Power Supply, with 9pcs Adaptor Tips, Compatible with 3V to 12V Household Electronics, 2Amp Output" supplies voltages mostly stepped at 1.5v intervals in well-marked and positively engaged steps when set by the enclosed key - a medium flat blade screwdriver will work equally well. It is unusual in that it has a means to reverse the polarity of the output voltage such that the numerous devices with a positive centre core connector are readily accommodated but, by reversing the tip, allows the relative few with a negative core to also be served.Some reviews appear to suggest that it is potentially dangerous to use, not to the user but to devices, because there is no certainty about tip orientation. That is INCORRECT and MISLEADING! The output lead is clearly labelled on its 'normal' side and provides a positive core when a tip is properly connected. Each tip is also very obviously labelled on both larger surfaces, one showing the core as positive, the other negative. It could not be much clearer unless in flashing red neon!In addition to subsequently purchasing one for personal use, one identical was first purchased by a family member as a power source for a single device, the alternative being an OEM PSU at more than twice the price as it requires a negative core supply and they are almost impossible to find as third-party alternatives! It was set up to meet its specific voltage and polarity needs and works perfectly.The tips are a very tight fit and need to be firmly connected until fully engaged - they will not easily accidentally disconnect - it needs a strong grip! The voltage dial, once set, will stay as-is and cannot easily disengage without the aid of the key or a screwdriver.Safety considerations are better implemented than with a similar product from another brand where its tips use an easily disconnected co-axial method and voltage adjustment is by a large knob whose position could be easily altered by a careless touch, passing pet or young child and pass unnoticed, risking the device should the voltage supply be beyond its limits - it does have a small LED display for output voltage but that cannot prevent an accidental voltage increase, only show that it occurred.

Does the job. Just used for a couple of weeks. No issues. Full range of voltages available to be able to run small battery powered equipment from mains power.

Works well, the only thing that would improve it would be to be able to change the power settings without the special key provided. Like a slider selection switch. That would have made it 5 stars.

dose what it says on the box, good quality

Packaged well. Nothing missing. Worked perfectly for a 12v ctr neg device that I needed to use. I would say that the polarity is a little ambiguous compared to others I've used.

It works a treat.. Covers all my needs in this one stop power source.. Highly recommended..Fast delivery..

This is a compact, quite powerful and versatile mains adapter at a sensible price that will provide 2 amps of output current throughout its range from 3 volts (where 2 amps = 6 watts) to 12 volts (where 2 amps = 24 watts).I bought this unit mainly for the reversible output polarity feature which consists of a decent length lead that terminates in a two-pin socket.What I liked:Nine of the more common sizes of DC barrel connectors are supplied, each of which 'plugs into' this in-line socket either way round.Output polarity (i.e. centre pin positive or negative) depends on which way round you insert the barrel connector onto the lead and polarity is marked on both the lead and plug-in connector: simply line up the arrowhead on the lead with the required polarity on the barrel connector and push the connector firmly home.The output voltage selector switch is quite stiff to turn, very positive and cannot be accidentally changed.The barrel connectors sit firmly in the socket and take some effort to remove, so they should not fall out inadvertently.Voltage regulation is very good: less than 0.05 volts drop from no load to half load - that's pretty stable!A separate USB A female socket is provided on the base of the unit with a 5 volts 2amp output rating.The unit stays very cool in operation and barely warmed up in over an hour's use on a warm day.The 5 Volt output from the built-in USB socket was almost right on the button at 5.06V: that's very good!What I wasn't so impressed with:The output voltages on the barrel connector were a tad high for my liking: nothing to worry about, but they were up to 10% high at the lower voltages. This is highly unlikely to cause any damage to connected equipment as a freshly-manufactured unused 1.5 volt alkaline battery can initially provide in excess of 1.6V. The output voltages on my unit are recorded below.Rated Actual3V 3.33V4.5V 4.71V5V 5.21V6V 6.18V7.5V 7.67V9V 9.06V12V 12.18VThe unit is double-insulated and does not have an earth connection (the earth pin is plastic, not metal), which results in a tiny amount of mains leakage current, but this is very low and I could only JUST detect it by rubbing the barrel connector across the inside of my wrist (it felt like a barely detectable nibbling sensation).Hint:If you find the range of barrel connectors included with the adapter is somewhat limited or does not contain the one you need, I extended the range by:1) purchasing this set of barrel connectors: Amazon part no. ASIN: B07F7776T62) connecting the 5.5x2.1mm barrel plug that came with the Soulbay mains adapter onto the two pin lead, selecting the required polarity.3) pushing the appropriate Aceyoon barrel connector for the equipment I was using onto the end of the 5.5 x2.1mm Soulbay barrel connector.A little bit of a christmas tree admitted, but it worked!Overall, versatile and not bad for the price, but the unit lost one star with me for the slightly high output voltages at the lower end of the range. This could just be that my unit wasn't terribly well calibrated: you may fare better.

My old switch mode psu, decided to call it a day, so I decided to go for a psu where the end connector of the PSU cable allows a polarity reversal to be made. I have two retro radios where the inner DC pins are negative polarity, so the two PSU l got do give you this polarity reversal option , and also allows you to set dc voltage output via switch on the PSU. A word of warning. Please see the diagram on the seller's Amazon site before connecting the PSU to any equipment. Most equipment with low DC voltage input do not tolerate a polarity reversal. Check your product manual for DC power rating. I have given 5 stars as the PSU are working.