[offtopic] need it for a led lamp.

Jump to Latest
e3k

e3k

Member
Joined 2010
#1
i upgraded to LEDs last year. i did know that the light can be bit shaky due to AC/DC conversion.


the lamp has a module of questionable origin with parameters on the output 700mA 34-47V.


is there some other power supply with more stable Voltage you could recommend me?


I am thinking right now about to dismantle some old audio PS and to use it there. :geezer:
 
#3
well in my opinion you want to have a stable power supply. the wire based bulbs stabilize the light output trough inertia of the heat of the wire.


leds in oposite are able to emit changes in the electrical signal much more quicker.


that is why you need a really calm machine. a battery would be ideal.
 
#5
ubergeeknz said:
LEDs require a stable current source. A small change in voltage through an LED equates to a large change in current. Yes it needs to be stable but it needs to have stable current, not a fixed voltage.
Click to expand...
i have only a voltmeter to measure it.
this is how it looks like. i mean just from the visual observation you might think this is cheap shaky China: power supply for a led lamp - Album on Imgur
 
#6
What you can do is find the nominal voltage for the LED cob, use a fixed DC supply, then you calculate a suitable ballast resistor to limit current to the desired level.

Probably (I didn't look) the cheap supply is not producing DC but chopping line frequency.
 
#10
ubergeeknz said:
Your meter have a current setting? I would measure that, then you have a good starting point.
Click to expand...
my meter has but i am have no practice with this. you have to switch the red cable from position mA to 10A... further the lamp blinked once i was measuring i don't want to screw things up.


what exactly should i setup on the meter to measure ~700mA?


-add yes i have done it in series that was ok...
 
#13
e3k said:
this is not measuring in series. i was told to measure A in series = under strain.
Click to expand...
It is but maybe not translating well. Here is a diagram, if it helps. export-4.jpg
 
#17
Fixed intensity LED driver modules provide a constant current across a voltage range. Any flicker if this is the problem or the fear could only be caused by fault in regulation loop or electrolytic capacitors aging.

Variable intensity LED driver of low profile design often uses voltage PWM and thus it often shows flicker, even faintly audible, although frequency is usually high enough to make it less noticeably than common 50/60/100/120Hz flicker.
 
#18
Eva said:
Fixed intensity LED driver modules provide a constant current across a voltage range. Any flicker if this is the problem or the fear could only be caused by fault in regulation loop or electrolytic capacitors aging.

Variable intensity LED driver of low profile design often uses voltage PWM and thus it often shows flicker, even faintly audible, although frequency is usually high enough to make it less noticeably than common 50/60/100/120Hz flicker.
Click to expand...
i could dismantle this and hook up stronger capacitors. this is faulty by design.
 
You must log in or register to reply here.
Top Bottom