My original AC Adapter for my Sega Genesis model 2 (10V 0.85A DC), so I found among my junk box (yeah, we all have one, right? Lol) a replacement (9V 0.2A DC). That said and considering the info perfectly explained on this post, I want to know if this new adaptor will harm my console?

That being said, I don’t recommend fudging the margin under the assumption that you can do the equivalent of driving 5 MPH over the speed limit with your electronic devices. The margin is there for a reason, and the more complicated the device, the more potential for something to go wrong.

5v Power Cables

In 2009, the EU created a common external power supply specification, a voluntary specification which encouraged mobile phone manufacturers to use the micro USB-B connector. As of 2016, most new mobile phones used this connector for charging. [ citation needed] Another example of this is zippers. Most are stamped ykk or ideal/i. These are zipper manufacturers nearly all clothing companies source their zipper supplies from. I am asking because on other forums, I learnt (I didn’t know) that Super Nintendos and Sega Genesis models 1 and 2 have internal voltage-current regulators which convert all power to 5V, despite the incoming power; that they could handle voltages from 3V up to 15V adaptors! Each AC/DC power adapter is specifically designed to accept a certain AC input (usually the standard output from a 120 V AC outlet in your home) and convert it to a particular DC output. Likewise, each electronic device is specifically designed to accept a certain DC input. The key is to match the DC output of the adapter to the DC input of your device. Determining the outputs and inputs of your adapters and devices is the hard part.

But next week I have a device coming that also has a US 2 pin plug but is rated much lower than a set of hair straighteners, rated at 5v/2a.But what if you accidentally (or purposefully) use the wrong adapter? In some cases, the plug won’t fit. But there are many instances where an incompatible power adapter will plug into your device. Here’s what you can expect in each scenario: You go to the store for a replacement supply, and they have two kinds of 20 volt power supplies, a 65 Watt and a 90 Watt. (Which is actually the case at my local computer shop, NCIX, except they’re 19 volts. But 20 makes for simpler math.) Which one should you choose? Most are either a brand we never heard of or just a generic “ac adapter” where you’d otherwise see a brand. The SAE connector is a physically self-mating hermaphrodite two-conductor DC connector commonly used for solar and automotive applications (also motorcycles). It is so named for the Society of Automotive Engineers who created the specifications this connector is based on.