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fixing Led lamp power supply

pharaon

Oct 28, 2014
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i have 48 pair of led connected in series total of 96 LED,the circuit failed in capacitor C1, the IC is TA320 which i can't find any datasheet for it except this information from Chinese webpage
Brand: Beijing-mode
Model: TA3720
Package: SOP-7
Input Voltage: 100-264V
Power range: 18W
Typical applications: serial 50 100MA
typical efficiency: 88%
Program Features:
①IC prostrate closed loop structures are used, no flicker, no When the current is off, the lamp beads will not die, and the lamp will not flash when wet.
②Support 1-50W power range, below 50W adopts built-in MOS/SOP-8 package structure.
③Achieve true full voltage output below 24 strings.
④Support PC20 core material, support chip I-shaped inductor.
⑤High-frequency and high-speed switching, the maximum frequency can be 120K, reducing inductance coils.
⑥Support the full service of the original factory FAE.

here is the diagram
2017719163340124.jpg


C1 value is 6.8μf,400 V which i can't find a replacement for it, i tried 10μf,450 V but that unfortunately blow the rectifier bridge.
R1&2 = 150KΩ
R7 = 1.9Ω
C2= 2.2μf 50V
R3 = 1MΩ
there's no R4 or R5 in my circuit






if i can't fix with different capacitor cause i can't find 6.8μf can i build suitable power supple with different component to power up the LED lamp
 

pharaon

Oct 28, 2014
435
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Oct 28, 2014
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it will cost too much to be shipped to my country ,more than the lamp price it self
 

73's de Edd

Aug 21, 2015
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Aug 21, 2015
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Sir pharaon,

I think that if you will measure from TA 3720 pin 5&6 over to pin . . . . . 7 and / or 4 . . . . . that you will read the low ohmmage of a short from drain to source of the power output FET that is built within that TA 3720 I.C.
Therefore it . . . . . will blow / has blown . . . . . the FWB with the resultant AC inrush to the 6.8 ufd . . . . uber-damaging it.
Therefore a 10 ufd as you tried to use, would have worked if the above mentioned situation was not present.

i have 48 pair of led connected in series total of 96 LED

Now, you say 48 LEDS in series . .? ? ? . . .
But might that actually be paralleled groups, which are THEN being wired in series, like:

Two groups of 24
or
Three groups of 16
or
Four groups of 12
or
Twelve groups of 4
or
Sixteen groups of 3
or
Twenty four groups of 2

( The BLUE - RED combinations are less likely )

Can you confirm the TA3720 ohmmage readings now ?

73's de Edd . . . . .

Now a days, you are all time reading about some select people saying . . .

I have always felt like I am a woman trapped in a mans body . . . like Bruce Jenner
or
I have always felt like I am a man trapped in a womans body . . . . Like Chastity Bono

Well now . . . . you wanna know WHATS ?


upload_2021-3-31_4-40-15.png

.
 
Last edited:

Bluejets

Oct 5, 2014
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Ed wanted 5&6 to 7 and or 4 ......the dot is usually pin 1 so you've given 1 to 5 and 8 to 5.
Couldn't see any data sheet on TA3720 so cannot be certain.
 

pharaon

Oct 28, 2014
435
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Oct 28, 2014
Messages
435
I think that if you will measure from TA 3720 pin 5&6 over to pin . . . . . 7 and / or 4 . . . . . that you will read the low ohmmage of a short from drain to source of the power output FET that is built within that TA 3720 I.C.

from bin 4 over to 5&6 it's 780 KΩ, and there's no pin 7
 
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