More regulation boards, this time from DX

[RV7]

http://www.dealextreme.com/details.dx/sku.3256

Looks like a dc-dc. Don't know how efficient they are. Probably not as good as 7135, but cheaper. May suck batteries hard and mandates the use of protected batteries.

 

[Randy Shackleford]

Anyone have more info about these boards? I think they might be the same board that in the ELLY light.

 

[Bertrik]

Very hard to tell without knowing the part numbers of the components. The Elly circuit is a boost (increasing voltage), this looks like a buck (reducing voltage).

 

[TMorita]

This looks very similar to the board in my Ultrafire WF-801, mentioned here: http://www.candlepowerforums.com/vb/showthread.php?t=164072

If it's the same board, it uses a ZXSC310.

Toshi

 

[TMorita]

They've updated the description on the board.

They say it uses a "C310 chip" so it is using a ZXSC310.

Toshi

 

[TorchBoy]

Toshi, what does that mean? What's a ZXSC310?

 

[Der Wichtel]

so it's also possible to turn it into a step up circuit

 

[greenLED]

Is that tape on the underside of the boards? :green:

 

[jsr]

If it's a Zetex ZXSC310 chip, the efficiency will be poor. The chip switches the load from the LED to a bypass transistor, but when doing so, current is still lost through the bypass transistor. Unlike a standard switcher, the Zetex chip seems to draw current from the source continuously.

 

[Der Wichtel]

hmmm... I've just bought them

 

[TorchBoy]

I can finally see DX again, so I've started thinking about these again. How much operating current does the Zetex chip need?

 

[Randy Shackleford]

so it's also possible to turn it into a step up circuit

details?

 

[TorchBoy]

details?

I assumed it was a question.

 

[mikeh]

details?

JFGI
http://www.google.com.au/search?hl=en&ie=UTF-8&q=ZXSC310
e.g. http://www.quality-items-flashlights.com/pdf/led-driver.pdf

 

[Bertrik]

As far as I can see in the datasheets, both the ZXSC300 and 310 are usually used in a boost configuration. Zetex application note AN44 shows that the ZXSC310 can also be used in a buck configuration.

 

[TorchBoy]

If it's a Zetex ZXSC310 chip, the efficiency will be poor.

http://www.zetex.com/3.0/pdf/ZXSC310.pdf says

FEATURES
94% efficiency

I suppose it would all depend on how it was being used.

BTW, what was so hard about posting a link to that datasheet? :shrug:

Product page: http://www.zetex.com/3.0/product_portfolio.asp?pno=ZXSC310

 

[lexina]

Here's my feedback:

I received 4 of these a few days ago but they don't seem to be working well. With a rated input of 3v-9v, I was hoping to use them as a buck driver. I hooked them up to an SSC P4 driven by 2 X 18650. It was very bright (measured current at the tail-cap was ard 500mA) but after about 5 mins, the led would shut down. After turning off the switch and resting a few minutes and turning back on, the led would light up again. This happened several times.

At one stage, I decided to leave the switch on after the led had gone off to see if it would light up again by itself after a while. It didn't and when I turned the switch off and on agin, the led was an angry blue! At this point, I removed one of the 18650s and it ran fine with just one 18650 which is what i have left it at (measured current went up to around 910mA).

I have not tried the other 3 yet so I don't know if the one I used was defective.

 

[TorchBoy]

That doesn't sound at all good, lexina. Would I be right in thinking that they're not simple buck drivers? Seems to fit if the chip is the one used in the lumiled micropuck.

 

[zelda]

lexina:

2 x Li-Ion = ~8 volts - 3.5 volts Vf led = 4.5 volts loss, thats a lot for the cirrcuit.

Maybe its too much. The Li-Ion batteries would die when the led begins with dimming. Its better you drive the 18650 in parallel.

zelda

 

[lexina]

That doesn't sound at all good, lexina. Would I be right in thinking that they're not simple buck drivers? Seems to fit it the chip is the one used in the lumiled micropuck.

I believe they are supposed to be buck drivers, just that mine doesn't seem to be working well. Maybe it's just the one I tried - I haven't bothered to try the rest cos I have no other suitable host. Will be interested in feedback from others who have bought these.