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How can I limit the current of my AC regulator? Answered

Dear All,

I am having a problem with my AC regulator that I use with my gadget. The AC regulator supply 12volts and 2.66 amps when connected to the grid. My problem is that my gadget used to be charged using 12volts and .660 amp, I noticed that when I plugged the AC regulator and connect it to my gadget it gets really hot after a short period of time. I want to limit the 2 amps so that the regulator then produce the required current.

I have quite a bit understanding with electricity and I want to know what kind of resistor should I wire with my AC regulator for that to be able to supply the said amount of current. Also can I wire a thermostat or a fuse that will shut down the system if it gets to hot? Please help me anyone?



8 years ago

It sounds like you have something in your gadget that's causing a short circuit, or a load current to be produced far in excess of the intended operation.

To prevent damage to the power supply, a fuse or circuit breaker can be installed on the output to trip past a given current.

To solve YOUR problem, I'd be inclined to open up said gadget and find the problem that's sucking so much juice.

BTW, since no one else said it, and since people will find it irritating to read and will generally comment about it, your ac regulator is technically an AC/DC converter, or in short-speak, a DC power supply. Consider that next time you need help...(no insult there, btw, just sayin)

Oh, and If the guts of the AC/DC converter, aka "DC power supply" are enclosed in a housing that plugs into the wall, it's called a wall wart.


Answer 8 years ago

regarding your question about over-temperature protection, yes, there are a variety of solutions available to the engineer. google "over-temperature switch" "thermistor", and "thermostat". You should find plenty of info to get your answer.


8 years ago

Your problem is with this "gadget", not the power supply to it.
What is is, how is it built/does it work?



8 years ago

  • There is no AC Regulator.  It is a DC Regulatorwhat I think.
  • 12 volts is most always DC  Not AC
  • When you say "grid" that is a HiVolt vacuum tube term
  • You notice your gadget is using 2Amps more then before  
  • 2.66A now from 0.66A before.
  • You want to put a 2A fuse or circuit beaker in series with where you measure this DC current.
  • I had a dream about this occurring under a bridge
  • An increase of over 200% is a good reason for something ( the regulator ? )  getting hot yes ?
  • You think a change of resistance value will help, I agree.
  • If I saw your circuit and a regulator part number.  Then maybe I could Help. :-)

Answer 8 years ago


You really are so helpful ever since. To cut my story short I want to limit the current from my regulator to just 600ma since this is the normal current that my gadget can handle. Is there in anyway you could please help me find out what is the best resistor that I could connect with the system. What I have is a 20 ohms 20 watts resistor that will be connected in Series with my output, which the vendor told me, but I have to make sure from the experts here if that is the right one.

Do you agree on this?


Answer 8 years ago

  • So you wish a 600ma constant current regulator schematic
  • What if your regulator type  So I can answer you ??