problem with HV9910 led driver: pls help me

[aminbehravan]

hi
I want to design a constant current led driver with this detail by HV9910:
input voltage: 200-240 V AC ___50Hz
output voltage: 54-108 V DC ___300mA
_____________________________________
I designed sample circuit like the HV9910 datasheet and i Get assistance of HV9910 software,
this picture is a result:


but when i connect it to 220V this circuit not work just LEDs make a little blink and turn off.

please help me to design it.

thanks for your help

 

[misterT]

hi
I want to design a constant current led driver with this detail by HV9910:
input voltage: 200-240 V AC ___50Hz
output voltage: 54-108 V DC ___300mA
_____________________________________
I designed sample circuit like the HV9910 datasheet and i Get assistance of HV9910 software,
this picture is a result:
View attachment 74741

but when i connect it to 220V this circuit not work just LEDs make a little blink and turn off.

please help me to design it.

thanks for your help

Input voltage to the circuit needs to be DC, not AC.. If you want to drive it from AC source, you need to rectify and filter the AC to DC voltage.
What kind of FET you have?

 

[aminbehravan]

hi and thanks for reply
i did rectified this and dc rectified = 195VDC. my mosfet is IRF840.
pls help me.
thanks

 

[dougy83]

The circuit is very simple. The most obvious problems will be due to incorrect wiring and defective or missing parts. Can you show a photo of your circuit? The diode connected to the mosfet and inductor should be fast.

 

[aminbehravan]

hi
my schematic:

my diode is "BYT43 fast"
in the last my testing, HV9910 exploded.
pls help me, Im confused.
thanks

 

[misterT]

My quess is that the circuit boosts the Vin above the maximum limit the IC can handle. I don't know why.. I can easily be wrong also. What is connected to the LED connection. How many LEDs?

Also, double check your connections.. for me the schematics are hard to read. First I thought that the FET is connected wrong, but the schematics were kind of "upside-down".

 

[ronv]

It could also be the current rating on the inductor. 12 Mh @ 300 ma is pretty big.

 

[aminbehravan]

hi and thanks for reply
i have 24 LEDs that need 77V DC.
my self is a RFC, i will try it with other inductor tomorrow, and write result.

again thanks for your help.
cya

 

[dougy83]

You have no bulk capacitor; see section "Input Bulk Capacitor" in the datasheet for details.

My quess is that the circuit boosts the Vin above the maximum limit the IC can handle. I don't know why.. I can easily be wrong also.

That would only happen if the circuit was incorrectly wired, not as shown in the schematic.

 

[aminbehravan]

HI.
for a sample i tested HV9910 in two circuit:
1: i tested HV9910 in 18VDC input for one led 1W, and that work Fine.
2: i tested HV9910 in 195V dc rectified for one LED 1W, but when i turn on circuit LED was light up a moment and then turn off forever (crashed)
all component same as ideal CALCULATION, just Rsense different a few milli Ω with of ideal.
i used fast diode and high wattage inductor.
pls help me guys, thanks a lot

 

[dougy83]

Have you added the input bulk capacitor?

 

[aminbehravan]

Have you added the input bulk capacitor?

yes i use 10uF 450 V.
i cant find higher than it on my town.

 

[aminbehravan]

forward voltage drop on a LED = 195 V
but i designed my circuit correctly

please help me, pls give me a sample circuit
thanks a lot