While looking for ways to trigger a siren through the internet I decided to make a small project using inexpensive modules. I decided to use the SonOff RE5V1C without an enclosure because it was the cheapest option available that would satisfy all my requirements. Likewise I used the LM2596S because it was a cheap and easy to use option unfortunately some of the mini options (like the LM2596 Mini Buck Regulator) are to cumbersome when adjusting the output voltage.
The number 1 major pain of this simple project was the red and black speaker wire I used…. This wire is actually more of a pinkish color and the insulation can be torn easily by my fingers however, the problem is dirty copper wire inside this cheap cable that would not solder even with a generous amount of flux.. I had to expose the copper and then try to clean them with vinegar and this partially worked.. However lots of time was wasted with this mundane cleaning. Even standard store bought ripcord solders fine compared to this wire….
Anyway in the end it worked out the way I wanted it to and it’s quite light and reliable, I have the whole system hooked up to a dedicated 12v battery that is trickle charged so when the power goes out the devices will still be operational for quite a while.
The RE5V1C uses from 80mA to 250mA according to the datasheet but I have a 40W siren connected to the relay so if triggered it will use from about 3A to 3.5A depending on the supplied voltage 11.5v – 13v
Looking at other mini ups manufactures I decided to give Jiageng a go. The outer plastic enclosure looks very similar to a lot of other generic mini ups devices. I suspect they all originate from the same factory but have slight improvment’s to the actual PCB inside.
Once opened I was greeted with a beautifully soldered matt black PCB with a higher version number than the previous mini ups from Andowl.
The PCB has quality components and no mystery chips. It also has the iconic Wintonic 18650 cells.
2 differences I noticed are that all the LEDs are a dark green color (the Andowl unit had 2 different greens) and the unit powers off automatically at a low voltage so that it doesn’t require a reboot after it runs “flat”.
The unit also has flashing LEDs as apposed to the Andowl’s fading LEDs
Datasheet can be found here. Andowl artical can be found here.
While load shedding continues to plague the average south African citizen I noticed that some of the well off citizens were not that phased out with the power going off and water running dry. Upon further investigation I found out that “big surprise” they had proper solar infrastructure and water tanks coupled with the right political connections they don’t need to suffer for decisions made by people who bear no consequence if that decision flops.
There’s nothing new about the facts I mentioned above however it got me thinking about looking for cheaper efficient and longer lasting solutions using technology even if they are not ideal its better to have something rather than nothing… what a shameful thing I had to say taking into consideration its the 21st century and governments are still using their governmental privilege to mess things up without facing a tar a feather spectacle such a shame..
Well unfortunately I can’t control things on a national scale but I can make a review of some affordable LED lights and hopefully that can help someone make a well educated effective decision to mitigate some of the frustrations and pain.
While browsing Takealot I noticed some prices fluctuate quite often but if you keep a price you are willing to pay in mind you can create a sort of mental filter that helps. So for this article I decided to search for LED lights containing these parameters:
Li-po or li-ion
5v to charge
Have an enclosure
Easy access and battery replacement
Decent circuit with charge protection
LED’s must not get too hot
I managed to find a product that came as a value pack (the so called emergency LED tube) and passed all my requirements. The product came as a value 3 pack of generic LED lights each light is about 32cm long and very light with magnetic discs.
I got mine at R210.00 for 3 emergency LED tubes that’s R70.00 for 1 so definitely affordable since I can’t get any 18650 battery for under R100.00 anywhere I have searched online in South Africa. I might just purchase these lights and harvest the battery in future just because it’s cheaper than purchasing the li-ion battery by itself.
The lights come with 1x unmarked 18650 battery and a charge controller chip with 1 button and a female micro USB port to allow charging via 5v
The button allows the light to function in 3 modes: bright, dim and strobe.
Even though the listing claims these lights are 18w when I tested them at a theoretical max of 4.2v (li-ion battery max) I only got around 10w and the LED strip got hot.
A few cons I noticed are:
Solder wires soldered directly on to the 18650 battery
Some joints were not soldered sturdily
Blue end caps can come off easily sometimes
All in all the lights did work out of the box however I touched up a few joints and glued one end of the blue cap just so it doesn’t come out when hanging the light via the plastic loop.
Once fully charged the light has lasted through 2-4 hours of loadshedding with a few hours of charge time.
Overall the light does its job and is affordable and the battery can be swapped or cascaded for longer lifetimes.
The only major concern I have it the lifespan of the LED chips and the mystery chip but only time will tell.