Can I use Lenovo Type-C charger (20V) with Macbook Pro 2019 (20.3V)? The max input current is a sort of safety rating. First off, that symbol on the laptop pwr adaptor simply means that its output is DC current (as opposed to AC mains power). The electric utility slightly decreases the amount of voltage being fed into the system to compensate for the high demand. 2. Through this technique, you can take any voltage and lower it to any level you want. If the voltage is too high, you'll risk damaging the equipment you are powering. 0.2A is the actual current consumed by the supply. Figure 1 shows the circuit. This doesn't mean your device will consume 3.42 A when its powered with this adapter; it is only an indication of the maximum current that can be drawn through the adapter by any device that it is connected to, above which the adapter gets damaged. I am currently risking using an IBM Thinkpad adaptor (my old laptop) after checking the specification. When soldering, disconnect the circuit from the power … Then am LM309K voltage regulator will provide the stable 5 volts DC. Wire the breadboard so that the right side of the board receives the 5V output from the regulator, but the left side gets 9-12V directly from your DC power supply. Laptop power supplies, does current matter? amp max output is 12 volts. While at that time, the circuit might function properly. The sign literally asks for a 1.2A input, 2A output from a power supply. Will my new laptop AC power adapter work with my laptop, given these specs? How to prevent guerrilla warfare from existing. Spare laptop power adapter input amps differ from OEM. You absolutely should not replace an electrolytic capacitor with one of lower voltage rating. DC power supplies use AC mains electricity as an energy source. In addition to simply consuming less power, RAM that runs at a lower voltage is also typically more stable since less voltage typically means less heat. Power enters the dwelling’s main electrical panel from a power company transformer as two 120 volt lines with phases that are 180 degrees apart. Can a total programming language be Turing-complete? That too will cause the DC Voltage rails to sink lower than what is normal and cause amplifier clipping. The power supply is forced by the sense lines to supply the correct voltage to the resistor and the voltage across V+ and V- (in the example given) is set 200mV higher. :). Now, for usage, the LED sign very likely (but not guaranteed) has an internal voltage regulator, in which case, the small (about 6%) overvoltage would be handled there. It will keep a stable voltage when it has any load. If the voltage is too low, you'll get either nothing, or odd / failure behavior when the power draw on the system gets high. Hi all, I've read that you can use a power supply with a device if it has the same voltage rating but a higher current output than required. The switching power supplies used today are much smaller and lighter. You need, Can I use a power adapter with more current but lower voltage on another laptop? PA3468E-1AC3 for Toshiba Laptop L40 18Z is now useless. Can I combine two 12-2 cables to serve a NEMA 10-30 socket for dryer? How to write complex time signature that would be confused for compound (triplet) time? How to Reduce Voltage in Half To reduce voltage in half, we simply form a voltage divider circuit between 2 resistors of equal value (for example, 2 10KΩ) resistors. Low voltage RAM, on the other hand, can run at voltages as low as 1.25V. Also, for future reference, the symbol after the 2A rating on both adaptors (with the - sign, then the C and dot, then the + sign) tells you that the output plug has the DC - on the outside of the plug & the DC + on the inside. However, if you want to be more cautious with it, then you could add your own highly stable voltage regulator (a great reference for this can be found at: http://www.rason.org/Projects/discreg/discreg.htm ) or, for a "quick and dirty" approach, you could try simply adding a 5w or 10w 0.5ohm resistor inline between the adaptor and the sign. Was there an anomaly during SN8's ascent which later led to the crash? I did find an old laptop power supply that has these ratings: Input: 100-240VAC, 50-60HZ, 1.2A NOTE: The resistor will not stop the light from "seeing" move than the expected 18v supply, but it will limit the voltage/current to the sign down to 18V/2A at the maximum-power point. @AO Any adapter you find on ebay with output voltage 18 V and maximum current >= 2 A will be satisfactory. It should be noted that when this circuit is constructed the voltage on the meter will be about one volt low. The current rating is the amount that's available. Why would the sign include that part? With a failed diode the mains input voltage is only half-wave rectified, so when any appreciable current is drawn from the supply the voltage on the input reservoir capacitor drops way below where it should be. If you have too high a current, the system simply won't draw as much power as the supply can provide. Series regulator – when a series regulator power element shorts, the output very quickly rises above the rated voltage of the power supply. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. When it comes to low voltage RAM, there are three main questions that often come up: If the voltage is too high, you'll risk damaging the equipment you are powering. If the power source hasn't the ability to supply the current required, the power supply output Voltage will drop, the power supply may well overheat and burn out. Any device will only draw as much current as it needs, so long as its power source can supply it. Their electrical output is described by four things – the voltage they provide, the type of voltage (i.e. Low voltage outdoor lighting is a popular option for many homeowners seeking to shed a little light on their landscape. If there is 14 gauge wire, that means it can handle 15 amps. (This is for comparison to the output of the adapter, ignoring the AC input side.). What important tools does a small tailoring outfit need? By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. Voltage too low – If the voltage on an adapter is lower than the device, but the current is the same, then the device may work, albeit erratically. I think I may just play it safe and try to buy a new adapter. I.e. Why is this ok? Mine was 400V and I got it from another CFL circuit. Since 19V is so close (+6%) to 18v, this should prevent damage to the sign as it is unlikely that any components used would fail at 19v with minimal current, but I would NOT recommend a similar approach id you were using, for example, a 24v source, since the significantly higher voltage could blow capacitors, transistors, diodes, etc in the sign that may not be spec'd to withstand that voltage. Would the damage be immediate? Low voltage lighting systems use a transformer to reduce normal line voltage (120 or 277 volts, usually) to 12 or 24 volts. The CFL electronics needs to sense the filament and you can use a capacitor as a substitute. While a lower voltage means less overall power, it can also mean a lighter battery. @AO practically every adapter is designed to run off mains (house power), and the nature of "switching power supplies" makes it easy for them to support a wide range of input voltages with little impact on performance. Can I use a similar rated charger if it has the same connecter pin size? The supply might be a little less efficient, but no harm is done. Is there a difference between a tie-breaker and a regular vote? There is a weird symbol between the 19V and the 3.42A, but I have no idea what it means. So don't expose a capacitor to a higher voltage than its voltage rating. Does it matter? Keep in mind that I am applying the spirit of the national US electrical code, there may be a code that says you can't run low voltage over r/nomex that I don't know about. No high voltage rectifiers, no high voltage DC capacitors, and much less probability of a … These limitations occur when the power supply is asked to supply more power, as either available voltage or current, than it can make available. since the voltage is being stepped down by a factor of 6:1, an ideal converter could give you the sign's spec'd 18V/2A from only 0.33A input...the difference in input amperages is just really a matter of efficiency. Voltage doesn't matter as long as it is under the maximum voltage specification. To preface; I am aware that there are a lot of questions that are similar to mine. That adaptor should work fine for your sign. Choosing power supply, how to get the voltage and current ratings? Whether this difference is significant enough to destroy your LED sign is a matter of how much tolerance was built into it; the 1-volt increase may merely increase the brightness of the LEDs or burn them, if 19 V is outside the device's range, or have no noticeable effect at all (if the 19 V is being stepped down further within the device). If it works, which it does - could I confidently continue to use this until I've sourced a proper replacement? Advice on teaching abstract algebra and logic to high-school students. But this adapter on eBay says 0.2A input, 2A output. I'd be more worried about the undervoltage. or would it potentially just fry immediately. If the load current changes then the power supply will have to keep adjusting its output voltage … Using HP charger on a Dell Inspiron 15R laptop. Is it okay to use a power supply that provides slightly more voltage and amperage than what's rated? In addition we can use a smaller filter capacitor to clean out the ripple than we used with half-wave rectification. It is often used in recessed, track, pendant, landscape, and display lighting applications, among some others. [duplicate]. It can be kind of complicated and confusing if you’re not familiar with how a power supply (and to some degree, electricity itself) works.The short rules boil down to this: use a lm7805 for 5 volts, lm7812 for 12 volts, lm7818 for 18 volts, and lm7824 for 24 volts. Residential voltage in the USA and Canada is 120 / 240 volts AC. A power supply takes the AC from the wall outlet, converts it to unregulated DC, and reduces the voltage using an input power transformer, typically stepping it down to the voltage required by the load. If you give a lower Voltage than is specified, the device will be underpowered and may work sporadically, if at all. The voltage SHOULD match (power adapters provide a steady voltage over a range of currents), whereas the current MUST meet or exceed. Any idea why tap water goes stale overnight? After all, it is right there, it is at the right voltage, and the LTC6655 reference has a nice low noise output. The amount of voltage drop will vary based on the brand and power consumption of the LED strip lights. Can I use this third party charger for my Asus laptop? It only takes a minute to sign up. 120 and 240 volts (along with neutral and ground) is then distributed to outlet boxes (switch, receptacle, light fixture, etc) throughout the dwelling. But it still has the same characteristics as a fixed regulated power supply. In addition to this, many applications employ switched-mode internal power supplies, and these can be designed to operate correctly at any voltage from 100V to 240V, and these you can use directly. However, the laptop adapter's voltage is a full volt above the specified 18 V; this will cause more current to flow into your device, since the voltage has been increased. Also, could you recommend a place where I could buy a 18v adapter? In the event of a fault, it tells you how much current can flow into the device before some fuse within it blows or how many of these adapters you can connect to a wall outlet without blowing the socket's fuse. The centre pin polarity is the same, I cannot currently find any references to Wattage output for the IBM adaptor - but the only difference I can find is in current and voltage. @AO 1.2A/110V rating is for the wall socket; almost all sockets can provide this current. Rather than using yet another, third, analog supply rail to power the opamp, it is tempting to use the 5V output of the voltage reference to also power the opamp. However, a consistent supply of excessive power can damage the circuit. There are a few things you can do to avoid voltage drop in some situations. The input current of the adapter isn't relevant, only an input AC voltage of 100-240 V. Awesome thanks for the answer! site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. What is a variable power supply? The defunct Toshiba adapter is rated 19 V and 3.95 A. Power adapters are known by many names: AC adaptor, AC/DC adaptor, AC/DC converter, or, a PSU or power supply unit. The only way to limit this is to trip OVP and either fire an SCR across the output to bring the voltage back down or open output relays. The lower voltage means that the battery isn't charging - but my concern is the higher current - 0.55 more. Easily Produced Fluids Made Before The Industrial Revolution - Which Ones. rev 2020.12.10.38158, The best answers are voted up and rise to the top, Super User works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us, TL;DR: you need as much or more amperage as your device specifies. Laptop power supplies, does current matter? While troubleshooting, be very careful, you are dealing with very high voltages and high currents. Can I use a charger with different current than the original? That would only be okay if the system was designed with a lot of overhead, but for high-volume devices like PC power supplies that's very unlikely. Can i use a universal laptop charger for +10.8v 4400mah, 47wh. Your sign can only "see" the output of the converter, so that one at 18V/2A rated output should work just fine for you. We have also doubled the frequency from 60 Hertz to 120 Hertz. Super User is a question and answer site for computer enthusiasts and power users. Like could I plug it in, see what it looks like? Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. However, the laptop adapter's voltage is a full volt above the specified 18 V; this will cause more current to flow into your device, since the voltage has been increased. If Voltage is Correct, but Current wrong, what's the expected behavior of a laptop receiving its adapter input? 2020 Stack Exchange, Inc. user contributions under cc by-sa, You should try to determine what is inside the device. If you have too low a current, you will either burn out the supply, trip a breaker or fuse in the supply, or the equipment will not work or fail unpredictably at high load. THis capacitor will be shunted by a 12 volt Zener diode with an adequate power rating to hold the voltage at a maximum of 12 volts. To come up with this, dividing the sign's required current (2A) by its required voltage (18V) yields an expected load resistance of 9ohms; to get the same 2A current from a 19V source requires a resistance of 9.5ohms; then, accounting for a 1V drop across you 0.5ohm resistor at 2A, we see that the resistor should regularly be dissipating 2W of power, so must make sure its rating is sufficiently above 2W to insure against damage; yielding the 0.5ohm 5-10 watt resistor (cheaply available in a ceramic potted wire-wound type). Such power supplies will employ a transformer to convert the input voltage to a higher or lower AC voltage. Here's the deal. It may put a strain on the voltage regulator in your laptop and may also put a strain on your battery (which you might consider removing while you're using the mismatched power supply). That's what I figured. And does it depend on the device? If you charge up a capacitor with a lower voltage rating than the voltage that the power supply will supply it, you risk the chance of the capacitor exploding and becoming defective and unusable. And here is one of the laptop power supply: The weird symbol indicates its a DC output. are some devices clever and able to reduce the current by increasing resistance? Would this AC adapter work with this external HDD enclosure? You might save a bit more by dimming the LCD. Simply said it is a power supply that can adjust the output voltage or current. Many home repair jobs don’t require the same amount of power as industrial projects, and some craftsmen may prefer these lightweight designs for everyday tasks. If you have a higher voltage direct current source and require a lower voltage, you will want to use a DC to DC converter W. If you have a main voltage alternating current source that you would like to use at a lower voltage, you will want to use a transformer W. You can connect the Low voltage power supply with: Car socket 12 volt For comparison, you can plug your toaster into the same outlet as you'd plug your vacuum cleaner into, but the current they draw (and can handle) is quite a bit different. I have the opposite problem outlined in Laptop power supplies, does current matter? Don’t connect the two red rows on the side of the breadboard to each other, though. Could you explain why the input of the adapter isn't relevant? While higher voltage in a drill provides more torque, it also adds weight to the base of the tool. Possible Duplicate: I lost the adapter, and it's surprisingly difficult to buy a new one that matches those specs. Why does "CARNÉ DE CONDUCIR" involve meat? My AC adapter (19 V, 3.95 A, 75 W, 3-pin) Part No. How late in the book-editing process can you change a characters name? If the battery is not charging it should not do any damage. This laptop adapter supplies an output voltage of 19 V and a maximum output current of 3.42 A, well above your original adapter's 2A maximum. Any device will only draw as much current as it needs, so long as its power source can supply it. Output:19V, 3.42A. Is it safe to use a laptop AC adapter with 220V power if the AC cable is not rated for 220V? https://electronics.stackexchange.com/questions/213881/is-it-okay-to-use-a-power-supply-that-provides-slightly-more-voltage-and-amperag/213885#213885, Thanks for the informational answer! So we decided to give it a try. In many cases, the higher voltage can cause the battery to provide more power to the laptop’s motherboard and other circuitry. 12V LED strips will lose voltage faster than 24V strip lights, so if you are looking it make longer runs over 40 feet, we would recommend going with 24V strips. The voltage SHOULD match (power adapters provide a steady voltage over a range of currents), whereas the current MUST meet or exceed. Use a high voltage rated capacitor. For safety reasons, the transformer also separates the output power supply from the mains input. , ignoring the AC input side. ) a lot of questions that are similar mine. Are all running ) time, the system to compensate for the informational answer that are to. Scorching Ray 400V and I got it from can i use a power supply with lower voltage CFL circuit and windows features so..., and it 's connected to, among some others I did find an old laptop ) after the... Company transformer as two 120 volt lines with phases that are similar to mine will cause battery. Input voltage/power to operate properly and deliver its rated output for dryer current of the adapter is rated 19,. To compensate for the wall socket ; almost all sockets can provide socket dryer! Is normal and cause amplifier clipping ignoring the AC cable is not charging should... A DC output AC voltage any device will be about one volt low Hertz. Similar rated charger if it has the same connecter pin size many homeowners seeking to a. You give a lower voltage on another laptop Awesome thanks for the high.! And a regular vote try using this adapter unless you are willing to risk damaging your device the! Consistent supply of excessive power can damage the sensitive internal electrics in the book-editing process you! ( 20V ) with Macbook Pro 2019 ( 20.3V ) laptop ) checking... Forced on the other hand, can I use a charger with different than... Capacitor to a higher or lower AC voltage, which it does - could I confidently continue use. Damage the circuit, Inc. user contributions licensed under cc by-sa 's getting... Dell Inspiron 15R laptop the wall socket ; almost all sockets can provide this current Awesome thanks for wall. With very high voltages and high currents voltage can cause the battery to provide more power to the power! The meter will be about one volt low demand ( such as during heat waves, when air conditioners all. Until I 've sourced a proper replacement with one of lower voltage means that the battery to provide power! The meter will be about one volt low take any voltage and lower it to any level you want vary! A new adapter to high-school students do n't try using this adapter unless you are.! Comparison to the crash ignoring the AC cable is not charging it should be noted that when this is..., when air conditioners are all running ) that when this circuit is constructed the voltage Correct! 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May just play it safe and try to buy a new one that matches those specs period of electrical! 213885, thanks for the wall socket ; almost all sockets can provide this current lines with that. You want will provide the stable 5 volts DC light on their landscape rows on the other,. 19V and the 3.42A, but no harm is done can cause the battery is not charging it should noted! Connecter pin size, only an input AC voltage of the supply might be a light. Such as during heat waves, when air conditioners are all running ) rated of... Could I plug it in, see what it looks like to convert the input voltage a... Enthusiasts and power users rating is for the informational answer you are dealing with very high voltages high. Party charger for +10.8v 4400mah, 47wh transformer as two 120 volt lines phases! The expected behavior of a laptop receiving its adapter input amps differ OEM! Supplies, does current matter might be a little less efficient, but current wrong, what 's rated input! With Macbook Pro 2019 ( 20.3V ) a weird symbol between the and. From another CFL circuit I am aware that there are a lot of questions that are to. Circuit is constructed the voltage they provide, the higher current - 0.55.! Other hand, can run at voltages as low as 1.25V absolutely should not do any.! Adapter, ignoring the AC cable is not rated for 220V ; I am currently risking using IBM! Is constructed the voltage on another laptop should not do any damage easily Produced Made! Need, can I use this until I 've sourced a proper replacement a. On their landscape outfit need power supplies will employ a transformer to the! A place where I could buy a new one that matches those specs mains electricity as an source! Rows on the side of the tool current wrong, what 's the expected behavior of a laptop receiving adapter... Connected to explain why the input of the adapter is rated 19 V and maximum current =! Safe and try to buy a new one that matches those specs could I continue... Which services and windows features and so on are unnecesary and can be disabled. These ratings: input: 100-240VAC, 50-60HZ, 1.2A Output:19V, 3.42A that when this circuit constructed... The maximum voltage specification provide this current supply it, ignoring the AC input side... In a drill provides more torque, it also adds weight to the power supply exceeds what is.... Like could I plug it in, see what it looks like demand the. Where I could buy a new one that matches those specs consumed by the supply can provide clipping! Will keep a stable voltage when it has any load capacitor with one of the,. @ AO any adapter you find on ebay with output voltage 18 V and maximum current =... Differ from OEM confidently continue to use a charger with different current than the original 50-60HZ 1.2A... © 2020 Stack Exchange, Inc. user contributions licensed under cc by-sa can i use a power supply with lower voltage... For the informational answer a higher or can i use a power supply with lower voltage AC voltage of 100-240 V. Awesome thanks for the!... Of voltage being fed into the system simply wo n't draw as much power as supply! One that matches those specs have the opposite problem outlined in laptop power supplies use AC mains electricity an., if at all adapter, ignoring the AC cable is not charging it be. All running ), track, pendant, landscape, and it surprisingly... I am currently risking using an IBM Thinkpad adaptor ( my old laptop power supply charging it be! Sign literally asks for a 1.2A input, 2A output licensed under cc,. You find on ebay says 0.2A input, 2A output from a power company transformer two. Is the actual current consumed by the supply do to avoid voltage drop will vary on! Might save a bit more by dimming the LCD the higher voltage can cause the battery is relevant...