Keep your Repeaters, Simplex Radio's and Raspberry Pi's cool

Image:  PWM Fan Contoller  (Click on image for larger view.)

Well this is a bit late to cool things down as we say good bye to summer and hello to winter.  I wrote several articles in the past providing information on building you own Thermo-Fan Controllers for use to keep radios, raspberry pi's and other electronic equipment cool during operation.  All of these controllers are still in operation on a daily basis and up to now I have not had any problem with any of them.

I recently noticed that my DMR Repeater fans are very noisy and I suspected that they are close to failure as they have been in operation for several years now.  Low and behold two days ago one of the TX fans decided that it had enough and failed as expected.

I considered to build another trusted IC741 op-amp Thermo-Fan Controller for use with the DMR Repeater.  As the years are creeping up on me and the eye-sight not being so good anymore I decided I would rather buy a ready to use simple/cheap PWM Fan Controller.   I ordered two different models.  In this article I will only provide information on the one model depicted in the images below.

The controller is designed as a model that combines manual control and automatic temperature control.

Here is more information on the specific model:

This single-channel PWM fan controller is designed for 12V DC fans, supporting both 2-wire and 3-wire fan types for precise speed regulation.

 

It enables smooth, efficient, and stable fan speed control, making it ideal for cooling systems, industrial equipment, and DIY thermal management projects.

 

Key advantages:

• Single-channel PWM speed control

• Supports 12V DC fans (2-wire / 3-wire)

• Smooth speed adjustment with low noise

• Compact module for easy installation

• Ideal for cooling systems and thermal control

 

Other detail:

Input Reverse Connection Protection: Yes
No output overload protection.
Power Interface: XH-3P Terminal Block (2.54mm Pin Spacing)
Fan current: 0.8A (not overloaded)
Fan Interface: KF2510-3P Terminal Block (Pin Spacing 2.54mm)
Temperature sensor parameters: NTC 50K B = 3950 Length = 50 cm.
Temperature Sensor Interface: XH-2P Terminal Block (Pin Spacing 2.54mm)
Temperature resistance of probe: ring probe 110℃
PWM Output Range: 5% to 100%
Operating temperature: -20°C ~ 60°C.
Dimensions: 43 x 18 x 9 mm. 

I am not going to go into detail on programming and setting up the controller as YouTube and Google is your friends here.

Finally:  I setup the controllers and tested them at different temperatures on the workbench.  So far they work as expected.  I will be fitting the two controllers in a 3D printed project box and install it at the back of the DMR Repeater to provide the necessary cooling when needed.

Images:  (Click on images for larger view.)

Videos:

 

Chinese quality control: USB 3.0 High Speed 4 -Port USB HUB ?

Here is another product from China that shows that quality control leaves much to be desired.  I recently bought this USB 3.0 High-Speed 4-Port USB Hub from a well known local emporium. It is really a nice looking product and looks quite durable from the outside.  The inside is another story which I will get to soon.  I bought this unit to construct a low power and low ampere distribution unit.  I will not be using the data lines for this project.  In my opinion this unit will work for my purpose.  I will in a future posting provide more information on the construction of the distribution unit.  Now back to what is inside this USB Hub.  It was easy to open the plastic box.  After opening the box and inspecting the unit it was clear that the soldering of the components were poorly done as can be seen in the images below.  The unit worked fine but if I was the manufacturer I would ensure that this shoddy type of soldering be addressed.   I know these units are mass produced but this is no excuse to sell a bad quality control product.  Be as it may my soldering iron did the necessary and hopefully no future dry joints will be experienced.  I also do not like the look and quality of the solder that was used.

Once again if you buy certain Chinese electronic products you might be in for a surprise of how the unit looks on the inside.  If I left the unit as I bought it, it might work for many years without any problems however I prefer good soldering joints as I had my fair share of dry joints from many electronic products including Icom Amateur Radios.  No I do not run Icom down.  I bought two brand spanking new radios from reputable dealers and experienced dry joints within the first week of using the radios.  Although fixed under the guarantee I never again purchased any Icom radios for my shack.  This happening with two brand new radios within purchasing them a month apart.  The end result  led to:

 "Once bitten twice shy!!"

 

Product Review: Replacing Smart TV Remote with a cheap Mini Keyboard

I thought to share the following experience with my fellow radio amateurs who might experience the same problem I recently had with a Smart Android TV Box remote control. (Image above.)

Not to go into much detail the grandson's remote control had a deep cleaning experience in the washing machine recently.  Needless to say the remote did not want to work after the cleaning episode.  I used a hair drier to dry the remote but to no avail.  It was dead!!

Looking online I soon realized that a replacement remote at R494.00 was out of the question.  A thought came to mind to try my wireless Shark Mini Keyboard I use when setting up Raspberry Pi's.  I plugged the 2.4 Ghz wireless dongle into one of the USB ports of Smart Android TV Box and switched the keyboard on.  Low and behold the keyboard worked flawlessly with the TV Box. I suggested to the wife that we purchase a new Mini Keyboard from a local Asian market.

With a price of only R110.00 I purchased one with backlit included.  My grandson was happy and I saved R384.00.  Not a big deal and I did not have to wait for an expensive online replacement.  This little keyboard can also be used with the grandson's TV,  Tablet, Sony PS3 and cellphone.  I'd say a bonus for the price as it includes a built in rechargeable battery.  My Shark Mini Keyboard is an older model and I must use 2 x AAA batteries.

What happened to the Smart Android TV Box remote control?

No it did not go to the junk-box or rubbish dump.  I took it apart and left it for 3 days in the sun without the batteries.  Well low and behold it came back to life and works without any problems.  Needless to say that my grandson now uses the mini keyboard instead of the remote.

This Mini Keyboard has many uses as already mentioned.  It also has a rightful place in amateur radio. Not only for the raspberry pi but many other projects where you need a small compact keyboard.

Images (Click on images for larger view.)

Above three photos:  Older W-Shark Mini Keyboard (No backlit or rechargeable battery)

Above 5 Images: New Mini Keyboard with backlit and rechargeable battery.