Results of an online survey about preferred tyres

I am facing some instability on my car rides and after showing it to numerous mechanics, wheel alignment centers everyone said the same: The tyres have gone bad and they need replacement. The car hasn’t had that much running to justify a tyre replacement so I started looking online for solutions. Finally I have to conclude after much online research that the tyres have gone bad.

With so many tyre brands available in the market at different price points it’s difficult to make a good selection by just reading stuff online and knowing about experiences of friends / mechanics. In a commission driven business model like India where every tyre vendor sells tyres of every company they would obviously try to sell the tyre that will fetch them most profits (exceptions exist, I know!). So to make a good choice I decided to run a survey on Twitter and Reddit. Posting the results of the same. I received total 41 responses.

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Call Rate comparison: Per second vs Per minute

A simple graph I made using spreadsheet to compare call rate in per second vs per minute. There was a similar graph somewhere around, but I lost the link and hence I made my own graph 😛

call_rate

1.5 paisa/second and 45p/minute are common rates in per second and per minute plans offered across India, so used that as base for creating my graph. If you are interested in downloading the spreadsheet I used for this calculation, you can do so here. It’s an OpenDocument Spreadsheet. I don’t use Windows nor MS Office. 🙂

Linode, you need a spam filter

I got this usual money scam email not directly, but via Linode Forum! Who even deploys Web applications without basic spam protection?!

Hello nileshgr,

The following is an email sent to you by joy kone via your account on
“Linode Forum”. If this message is spam, contains abusive or other comments
you find offensive please contact the webmaster of the board at the
following address:

https://forum.linode.com/memberlist.php?mode=contactadmin

Include this full email (particularly the headers). Please note that the
reply address to this email has been set to that of joy kone.

Message sent to you follows
~~~~~~~~~~~~~~~~~~~~~~~~~~~

From: Joy Kone

I have sent you this e-mail because of the need to open discussions with
you. I don’t want you to misunderstand this offer in any aspect…if it is
okay with you, I ask for your full cooperation. I have contacted you base
on trust to handle an investment in your country/company on my behalf as a
prospective partner.

My name is Joy Kone. a citizen but resides here . It might interest you to
know that I have US$10.500,000.00 deposited with a financial institution to
be invested in your country/company. It is pertinent to let me know if you
can handle this fund/investment with you in your country so as to furnish
you with all the necessary details about the financial institution for more
information. Meanwhile, i am very honest in my dealings with people and I
also demand the same from you as a Partner to be. Can I trust you with this
fund?

I want you to note that this is a mutual business venture as t here is a
reward for your assistance. I shall let you know your benefit for your
assistance as we proceed. For a more comprehensive details and source of
fund, please contact me as soon as possible. If you find this letter
offensive, please ignore it and accept my apologies.

Regards,
Joy Kone

Okay I received a reply from someone working at Linode, apparently it is possible to turn off the ability of others to send email to you via the forum:

The PC reset problem with Active PFC SMPS and UPS

I have a desktop machine with a Corsair SMPS which has active power factor correction. I had a Luminous 675 VA UPS before buying my new desktop machine with this SMPS. The cheapo power supplies available in India (which cost a fourth of the cost of branded ones like Corsair, etc) do not employ power factor correction.

When I was deciding on the configuration of my machine, I decided to buy the latest Intel i5 (i5-4670). The processor had been launched just around a month or two ago. I also bought Gigabyte motherboard and Corsair cabinet after recommendations from many geeky friends I know online who have built their own desktops. They also suggested me that since I was already spending a lot on the machine, I should definitely go for a branded SMPS in order to protect the components instead of going for a cheap one and risk the components.

I did not know that there were compatibility issues with UPSes and Active PFC power supplies. This came to light when my computer started restarting whenever there was a power changeover by the UPS because of high voltage in the input or a general power failure. Because this wasn’t happening for almost 1 year after I bought my computer, I thought something was wrong with my UPS. So I called up Luminous support and they sent an engineer for inspection. He found that the battery terminals had corroded. The Luminous UPS I have supports those big batteries (12V / 100 Ah is the battery I was using) and it claims to be sine wave UPS. He then cleaned them up and things seemed to be back to normal (they just seemed, also known as placebo effect :P). The problem returned back after a few days.

I even tried giving my SMPS for a warranty repair to be sure that the issue is with my UPS and not with the SMPS. Then I started researching about this. I found that this was a known problem (involving big brands like APC!) and the reason was certain PSUs expected pure sine wave at the input but the UPS available in market were outputting modified sine wave, and that’s apparently the oscillator circuit for which is far cheaper and easier to design compared to pure sine wave (Pure sine wave is what you get from the power supply company at homes). I still don’t know if the real cause of the PC getting reset during a changeover is because of the sine wave / square wave thing or it’s because the switch time of the UPS is higher. But if it was a delay, it should happen every time there is a changeover which wasn’t the case.

This clearly indicated that whenever the power waveform at the UPS had an unexpected form, the SMPS was cutting supply to my PC. During the research, I came to know about the kinds of UPS. There are basically two kinds of UPS, one is line interactive UPS and another is online UPS. The difference between the two is that a line interactive UPS will supply AC power directly from the power socket it is connected to as long as there is power and a relay like mechanism is used to switch to battery when there’s an input power failure whereas an online UPS supplies power from the battery all the time. Whenever there is input power available, it will charge the battery. There’s zero switch over time in case of online UPS, while for line-interactive UPS it’s 10-15 ms.

I asked my inverter vendor if he had online UPS and I got shocked when he told me the price for a 600 VA online UPS: ₹25000. That’s way too much for me. Line interactive UPS of the same size costs less than half of that price. So I started manually using the UPS in battery mode whenever I was working on my computer. But this problem needed a solution. So yesterday, I bought a second-hand UPS for ₹250 (yes, that cheap. New ones cost around ₹2000) which supported 600 VA load at output, but the charger inside it cannot charge big batteries. I decided to use my bigger line-interactive UPS as a charger for the battery while this thing will power my computer.

I just bought two wires for connecting the battery and this new UPS. I also added a fan to inside the new UPS’s enclosure to keep the transformer cool as I had the experience of cooking up the transformer during this experiment in another 15-year-old UPS I had. Now things are smooth. Apparently 12V battery chargers are available for ₹4000 on eBay. So why is an online UPS so expensive?! That remains a mystery to me.

IMG_20150322_090659

A Linux geek’s experience with Windows 8.1

End of October, my Nexus 4 died, apparently due to a bad battery. What happened was the phone switched off automatically (not the low battery switch off, but at some random % > 50) while using a couple of times. That ended up getting worse by corrupting something leaving the cell radio in a non working condition. There’s no IMEI number, no baseband version and any Android version > 4.2.2 doesn’t boot.

A bit of research on Google yielded not much information. I took it to the service centre and they told me the motherboard would’ve to be replaced which was costing me ₹10000. That’s too much to pay for a 2 year phone especially when you get a completely new phone for that price (well, may be a bit more than that). Meanwhile I found a thread on xda which revealed an de-bricking method using some proprietary LG tools, which unfortunately worked only on Windows. This was a big disappointment for me, but that’s well-known fact that Windows has more market share in PCs than anything else.

I had to try it anyhow, so I first tried playing with VirtualBox’s and QEMU-KVM’s USB Passthrough on my old Windows XP VM (I had it around for working on college stuff… education curriculum in India is highly closed source-agnostic, to the extent some computer engineers won’t even know that there exists an OS called GNU/Linux!), which failed. It works for simple storage devices though, but for some reason the serial device (it comes up as ttyACM0) in the download mode (in which mode the LG tool will send a firmware image) couldn’t be accessed properly in the virtual machine. So I decided to buy a Windows 8.1 key from Microsoft Store, I was kind of sceptical about Windows since I left it back in 2007 because of constantly nagging problems like malware, random slowdowns, freezes, etc and shifted to Linux. Thanks to my student account I was able to buy it at a discounted rate of ₹3499 as opposed to the usual rate of ₹19k for the Pro version. I also noticed that they have a 14 day return policy, so I was a bit okay with the spending.

My hardware configuration is pretty simple, I just have desktop with i5-4670, 8 GB Corsair, 1 Samsung SSD and 2 HDD (WD, Seagate). The HDDs are in RAID0 striping in Linux and deliver good performance compared to a single HDD (read speeds are around 190 MB/s). There are two reasons for having such a simple configuration – first, I don’t game and second, excellent Linux compatibility. I had a thought of gaming since a long time, but never had the courage to face Windows (well, after being used to Linux for 5+ years, I doubt anybody will) and hence never played games.

So, let’s put the hand in lion’s mouth.

Continue reading “A Linux geek’s experience with Windows 8.1”