DTR?

[RedCowboy]

I just got 5 little buck converters for 75 cents each, well 5 for 3.25 plus 1.50 shipping so 5.25 total delivered to my mailbox so 1.05 each
They are voltage regulators not current regulators ( yes I know laser diodes need constant current ) but my point is they have pots, inductors and 8 pin chips, so we should be able to have our op-amp based drivers made in China using Chinese made parts for about the same if we bought 1000 at a time ??

https://www.aliexpress.us/item/2251832600462332.html?spm=a2g0o.order_list.order_list_main.10.21ef180282ByB4&gatewayAdapt=glo2usa

 

[paul1598419]

Yeah, I bought a bunch of these buck voltage regulators several years ago thinking I could modify them. But, that turned out to be very difficult as I was unable to get any schematic diagrams for them. Still have them around here somewhere.

 

[RedCowboy]

I wasn't talking about modifying them although that could be possible, I am talking about having pot adjustable constant current buck/boost drivers made to spec in quantity using Chinese sourced parts.

 

[paul1598419]

I know. I was just talking about what I did.

 

[Giannis_TDM]

Hi G,
No offense you have great drivers buddy. I was only reminiscing when we had a multitude of a great selection. Hope you checked out the link I posted what an assortment we had back then. Keep up the good work .
Rich

Yeah, expect way more out of me when summer comes round, There will be 5 drivers in my lineup. Open source 3A buck, Open source 1A boost, 800mA small boost, 4A buck, 1A buck boost with extreme fine adjustments (we are talking 11 turn potetiometer here in the normal 10mm x 15mm format.)

 

[Giannis_TDM]

I wasn't talking about modifying them although that could be possible, I am talking about having pot adjustable constant current buck/boost drivers made to spec in quantity using Chinese sourced parts.

Just putting in my 2 cents here, Thats what astralist did and you can remember if you used his drivers (cause I have) how sensitive they are to blowing up at the slightest mistake. Besides that, when operational they were mostly fine.

 

[Giannis_TDM]

Yeah, I bought a bunch of these buck voltage regulators several years ago thinking I could modify them. But, that turned out to be very difficult as I was unable to get any schematic diagrams for them. Still have them around here somewhere.

Its not really that hard to implement, just need a shunt, a vref a current amplifier and a high slew rate opamp. and of course a potentiometer. Although IMO that configuration compared to a discrete IC that is made for CC is more failure prone if the designer does not think of everything 200% correctly, cause when you work with feedback loops, small issues easily get rectified into large ones, For example, if the output range of the opamp is miscalculated, at a certain current set the 2 loops will be 'fighting' for 'dominance', that could in turn knock the IC out of regulation and have it switching in the audible range, if it spits out a current spike then, game over for diode.

 

[Darktron]

With archive.org you can use the direct link to the diode.
Remember to download the images you need.
As always thanks to DTR for all his hard work.