Maker Pro
Maker Pro

fixing Led lamp power supply

pharaon

Oct 28, 2014
444
Joined
Oct 28, 2014
Messages
444
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
444
Joined
Oct 28, 2014
Messages
444
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
3,629
Joined
Aug 21, 2015
Messages
3,629
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
6,952
Joined
Oct 5, 2014
Messages
6,952
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
444
Joined
Oct 28, 2014
Messages
444
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
 
Top