TOP257YN SHUT DOWN WITH LOAD
hi
I m Design smps using TOP257yn.op are Sec1 57v/1.4A & Sec2 15v/0.1A (Sec2 are currently un use
my problem is that when smps on with out load gives 57v out put check contineous 8 hrs. but when connect the full load,1/2 load & 1/4 load,after 2 or 3 mintes smps shut down automatically
all components are use as per PI EXPERT7.1 Results pls give solution urgently
Comments
Hello
I m assemble onther 03nos pcb of based on TOP257yn IC.in all 03 pcb faced same problems,when I connect 1/4th load of high power Led based Street light my smps is working ok but when I connect 1/2 load .led street light gets continueos blinking.Pls give me solution in urgently. smps o/p are 57v/1.4A.with this im attach schematic of smps.
Im test 24v/1a circuit with this top257yn ic &same pcb layout.it is working ok with full load.
Regurds
Irfan memon
Hello
I m assemble onther 03nos pcb of based on TOP257yn IC.in all 03 pcb faced same problems,when I connect 1/4th load of high power Led based Street light my smps is working ok but when I connect 1/2 load .led street light gets continueos blinking.Pls give me solution in urgently. smps o/p are 57v/1.4A.with this im attach schematic of smps.
Im test 24v/1a circuit with this top257yn ic &same pcb layout.it is working ok with full load.
Regurds
Irfan memon
Can you send me the PIXls or PI Expert design file for this? Continuous blinking indicates that the supply goes in auto-restart. Because the supply works for 1/4 power, this is most likely because the output is falling out of regulation. This can be a transformer construction issue.
PLease attach the transformer drawing also.
Pls find the attachment of pi expert Design & transformer Detail of 47v/1.4A smps
Lets try a few things here to see where the problem could be coming from
1) Ground the V pin (yes you will lose the UV/OV functionality for the time being) and see if the problem goes away. If it does, the V pin is picking up noise...
2) Short out R40
3) change C85 to 47 nF
4) Change R38 to about 1.5 k
5) Change C21 to 100 or 220 uF
2 through 5 will address any loop issues.. I will tell us if layout is causing the V pin to pick up noise.
your suggested all 05 options are applied but still the problem are as it is.
Other helpful hints are, I sending you some voltage for reference
No load voltages
VOUT TL431 TL431 OPTO C
PIN1 V PIN3V PIN1V
55.2 2.37 48 49
1/4TH load voltages
VOUT TL431 TL431 OPTO C
PIN1 V PIN3V PIN1V
53.1 2.31 47.2 48.3
1/2 load voltages
VOUT TL431 TL431 OPTO C
PIN1 V PIN3V PIN1V
52.2 2.28 46.4 47.8 - VOLTAGE AT ON POWER ON TIME
53 VOLTAGE AFTER 1MIN
54 VOLTAGE AFTER 2MIN
55.2 2.18 47.3 48.4 VOLTAGE AFTER 3MIN ,,RESTART (LOAD BLINKING)AFTER THIS POINT)
-24v/1A smps are working ok with TOP 257yn design are test on same pcb layout so i think no issue of noise
-For your information
We are developed transformer 03 times
In same circuit 1st two transformer are working only without load, last one transformer are working ok with 1/4th load only
Pls suggest more option how can resolve my smps problem
What is the temperature of the TOPswitch? Please measure temperature near the tab with thermocouple. IYour problem indicates that the chip is shutting down thermally. How big is the heatsink that you are using in terms of thermal resistance?