Astral Driver For Sale - Boost, Buck, Buck-Boost, Linear, & Etc

[Coonie]

Are the picodrives available?

 

[paul1598419]

Out of the first four drivers I used out of my order, one was defective right out of the bag. It has a very low input resistance on the supply leads. I hope the rest are fine, but some other members were saying they had similar problems with some of theirs. :thinking:

 

[Coonie]

Out of the first four drivers I used out of my order, one was defective right out of the bag. It has a very low input resistance on the supply leads. I hope the rest are fine, but some other members were saying they had similar problems with some of theirs. :thinking:

Are they not reliable then?

 

[paul1598419]

I didn't say that. Only that one out of four failed out of the bag. For the money they seem to be a good deal for a boost driver especially if you order several as the shipping is a bit high unless you go for the cheaper $6.00 shipping. I had a recent bad experience with that shipping method as my package got to within ten miles of me and after ten days of trying to get the USPS to deliver it, they sent them all back. So, the $16.00 shipping would be the preferred method.

 

[Alaskan]

Paul, it's only some of the pico drives which have had that problem, or others too?

 

[paul1598419]

All I know is I had one that was bad out of the bag and another member had the same problem. I can't say for sure how many were bad in total because I still have three drivers I haven't even tested yet. My hope is that they are all good.

 

[Alaskan]

I tested the inputs for a low resistance on ten of my pico's last night and all of them didn't have it, so they don't have that problem, still need to wire and test them.

 

[paul1598419]

I can't say that mine had it prior to firing it up under load, so the failure that causes the low resistance may not be there initially. It seemed to not pull any current when I first put a supply to it, so look for that.

 

[Coonie]

I can't say that mine had it prior to firing it up under load, so the failure that causes the low resistance may not be there initially. It seemed to not pull any current when I first put a supply to it, so look for that.

Sorry that you're having trouble. For the most part they seem reliable to a decent degree.

 

[jnrpop]

Out of the first four drivers I used out of my order, one was defective right out of the bag. It has a very low input resistance on the supply leads. I hope the rest are fine, but some other members were saying they had similar problems with some of theirs. :thinking:

Are they not reliable then?

Paul, it's only some of the pico drives which have had that problem, or others too?

I can't say that mine had it prior to firing it up under load, so the failure that causes the low resistance may not be there initially. It seemed to not pull any current when I first put a supply to it, so look for that.

I was setting up an osram PLT5450B 300mA diode tonight with one of Astrals new Picodrives, unfortunately my connection to the diode was loose and it LED'ed, but before i new this, i connected the new Picodrive to my testload and it was fine, still outputting ~250mA, then stupidly, i changed the diode amount on the testload from 4 to 6, without dis-connecting the drive, long story short for a split second the driver had an open-load and....DIED....i know due to the smell of the magic smoke

So i lost my diode and driver :banghead: ....it appears an open-load with these new Picodrives will fry the IC, this could be a possible cause for the above problems, possibly not but something to consider....check your solder points are solid!

 

[paul1598419]

Having any boost driver under power and losing its load will always kill the driver. It was not the cause on my failure as I solder leads to all four contact points on the driver and have the load securely attached to the driver at all times. I do it this way so I cannot have an intermittent connection on the load that will kill my driver. If I had an intermittent connection on the driver's output, it would have pulled current from my supply.

 

[deadshadow]

same here,no way to had a bad connection as i had soldered a string of diodes that i use to simulate a high vf diode,i also had an antistatic strap,things happened that way to me,i soldered the diode series on the driver and then i connected the driver on my psu only to find out that even at 0,5v it was drawing any current that i let it get,after a thorough testing with Astralist's help i found out a shorted capacitor on the board,after removing it the short was gone but i got no output and assumed the ic fried from the short.

i think this was a very small defective rate as the only incidents was mine and paul's while Astalist sold a big amount of them,nothing to worry about in my opinion.i used the other 2 i got that working great and this is a great driver with minimal or not heatsink requirments for up to 0,5A

 

[paul1598419]

I think you might be right, Chris. I am hoping so, anyway. It was only the one driver and the rest, so far, have worked fine. I am not terribly concerned about my one driver failure. If one of the other three fails, that could change my outlook entirely, though.

 

[astralist]

Great discussion!

About testing the "continuity" or short-testing using multimeter:
You need to be aware as the (usual) multimeter will supply about 3V when set into continuity test. This leads into powering up the driver and thus act the same way when you power it up using 3V battery, i.e the output voltage will go up and up until the IC dead (if there is no load at output)

Luckily, if you are using pretty good DMM, it will limit the current to the probe, so the driver will not draw high current (which will translate to big duty cycle or big Vout/Vin)


About the defective drivers, it seems the one that is defective is the capacitor. But i don't know for sure as i'm unable to reproduce/find the issue here.

I have also a customer in ebay reported two of five driver are defective, but he said after desoldering again and again, one of two defective is finally working.
The other defective one is drawing high current while giving no output. It seems he doesn't have multimeter as he don't know wheter the input or output which is shorted.

Apparently doing random testing is not enough i guess :yabbem:

 

[paul1598419]

My DMMs only use voltage under 0.5 volt in ohms mode. They do use higher voltage in diode mode. I never check these in that mode. So, I seriously doubt this caused any failures of my drivers.

 

[Alaskan]

Same here, I don't use the "diode" test mode on my DVM to measure resistance.