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how to make a 240v 2A dc power supply?
i need a 240v dc power supply for a project but my pablum is ,i need to reduce the current up to 2 amps
i know how to reduce the voltage but how i can reduce current ?
i need a 240v dc power supply for a project but my pablum is ,i need to reduce the current up to 2 amps
i know how to reduce the voltage but how i can reduce current ?
Comments
3 years ago
Can you tell us WHY it needs to be current limited to 2 amps.
In general items draw the current they need. If your wanting a safety limit put a 2 amp fuse in line with the supply.
Answer 3 years ago
current limiting circuits
https://www.google.co.uk/search?q=current+limiting...
3 years ago
Perhaps mains power, plus a simple rectifier circuit, half wave, or full wave, etc:
https://en.wikipedia.org/wiki/Rectifier#Rectifier_...
Then put that in series with one or two incandescent light bulbs,
https://en.wikipedia.org/wiki/Incandescent_light_b...
for to effect your current limiting.
I mean, what I have described is the, uh, "cheap and dirty" way to do this.
Actually, for not much more cost, you could throw in a TRIAC based lamp dimmer,
https://en.wikipedia.org/wiki/Dimmer#Solid-state_d...
to sort of throttle the mains power, and give you AC with less RMS voltage before the rectifier stage.
Regarding cost, cheapness, if you have ever gone shopping for a power supply, you might have noticed price tends to scale with power capacity. So that a little 5W thing to charge your phone is really cheap, and a 30 W brick for charging a laptop is maybe moderately priced.
When I multiply the two numbers in your spec together, I get 480 W, and that is kind of a big number. So there might be some sticker shock, if you actually go shopping for, and find offer for, a professionally made 240VDC, constant voltage, with 2A max current, power supply.
Answer 3 years ago
+1
Excellent answer...
Vina should realize a current limit operates by lowering the voltage when you start to draw over 2 amperes...
Answer 3 years ago
Be aware though that at these levels DC will be deadly to the touch....
Answer 3 years ago
I have twice survived 240 VAC across my chest..
Once got my hand frozen to an arcade gun game after swimming my feet were bare and wet. This occurred at a girls basement with a dangerous faulty un-grounded limited motion metal pistol target game.
The current froze my muscles to the grip and I could not even call for help..
Eventually I was able to release my left leg enough to fall down which pulled my hand loose from the current source.. I was an EE at the time and twice warned the family of the lethal game !
The girls father was totally unconcerned of the danger in his home and I later stopped dating her.. No idea what ever they did about my warning..