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Thursday, April 14, 2022

DIY simple PC fan/cooler speed regulator with LM317T

After wasting some time online, I was surprised I couldn't find any simple LM317T schematic for PC fan speed regulation with a potentiometer. WTF?

So I share my version. The values are intended to be easy to find lying around.

Worth noting:

- As with any LM317 based schematic, the maximum output won't reach 12V but a bit less.

Le me know if you found this useful.

DIY 3.5" hard drive power supply for USB cable

 I got this USB interface from Aliexpress that allows you to connect any HDD/SSD to your USB ports.

Unfortunately 3.5" hard drives need external power in order to work. You can get this power from a ATX power supply or from a dedicated hard drive power supply that can be found online.

To keep my shit low cost I built my own power adapter with things I had around. I used:

12V 2A power supply. Got it from an old router.
- Mini 360 DCDC converter. Dead cheap from Aliexpress, so useful. Must have several at home.
- SATA or IDE power connector. Chopped from an old ATX power supply.

The build is so simple:

Worth noting:
- The Mini360 output voltage is adjustable with the potentiometer on top. You need to set it to around 5V with a multimeter.
- Wall adapters with lower output current than 2A will almost surely not work due to the required start up current of the HDD. (Tried with 1.5 A, didn't work).
- I used a piece of heat-shrink tubing to cover the mini360 and make it neat in the middle of the cable.

Let me know if you found it useful.


Friday, April 8, 2022

Olympus M.Zuiko Digital 14-42 mm II R vs EZ (pancake)

 If you doubt about what lens is better among the 14-42 II R and EZ, let me tell you what I found. This is a compilation of all the info that I found online. I'm no expert. This may save you some time.



The only advantage of the EZ is the small size, period. It seems it depends on your specific unit how well it performs. At best you can get the same results as with the IIR. At worst people seem to experience vignette and/or a little bit of lack of sharpness on the edges. It seems a mixed opinion. In any case, no one claimed to obtain better picture quality with the EZ. 

The electronic zoom on the EZ seems to be slow and significantly less easy to operate due to the electronic control. A noticeable amount of users reported issues with the electronics that required servicing the lens giving the impression that it's less robust than the manual IIR.

On the other hand, the IIR seems to be better at everything other than the size. Regarding this, the difference is only 25 mm in length more than the EZ which isn't a big deal. 

I think the IIR is the one to go. I reckon the only case in which the size can make a difference is if you wear a big jacket because you can fit the camera with the EZ and not with the IIR. However wearing any other clothes you're going to need a bag or something else anyway. Even if it fits your clothes, will you carry it like that?