Posts Tagged ‘howto’

Understanding a Fan Motor

August 28th, 2012 4 comments
Have you opened up a fan motor before?  It is a simple brush less A/C induction motor, where the armature remains as the stator.  Look at the exploded image of a typical fan motor. The important parts are C: Ball Bearing, D: Stator, E: Armature/Stator, G: Capacitor, H: Connector. 

Also, look at the other image that shows the cross section of a motor.  You would notice that there are 4 wires coming out the motor.  Two pairs of wire, with one pair as the starting coil and the another pair for the running coil.  In general, all single phases induction motors have two coils (starting coil, running coil).  Using a capacitor, an artificial phase difference is created between the fields created by the starting and running coils.  The phase difference triggers movement of the armature.  When the armature reaches a particular speed, using a centrifugal switch, the connection to the starting coil is disconnected and the entire fans runs with just one coil.

Although there are four terminals, you would notice 3 terminals are emitted out, with the starting and running coils connected back-to-back.  Let’s say S1,S2 are the terminals of starting coil and R1,R2 are the terminals of the running coil.  To get 3 terminals out of the fan motor, S2 and R2 are shorted. 

Now, you just see 3 terminals; how do you find which terminal is starting, which one is ending and which one is shorted?  Easy.  Using a simple multimeter, you can find it out.

Let’s say you see terminals A, B, C. Our aim is to find which one of these are S1, R1, S2R2.  Now, let’s measure the resistance between A-B, call it X.  Likewise measure the resistance B-C as Y and A-C as Z.  If you would notice X < Y < Z, you would also notice that Z = Y+X.  Which mean, A-C is action A-B+B-C, that’s why the resistance was additive, also the terminal B is S2R2.  The challenge now is to find what is A and what is C.   As we’d notice A-B=X < B-C=Y, we can confirm that terminal A is starting coil S1 and terminal C is running coil R1.  The reasoning is that; starting coil resistance will be less than running coil resistance.

Hope, this article helped.

How to Remove The headlamp – Getz Prime

September 24th, 2011 No comments

Removing the headlamp from Getz Prime is pretty trivial and requires just only one tool and probably 5 minutes of time.  Let’s see how to go about that.

1. The Headlamp Assembly: It appears very dull ey? Yes, I was going to remove it and replace the frontal glass.

2. The Tool: All the bolts that attach the assembly to the chassis are 10mm and you would need a bit rod for disassembling the headlamp unit.

3. Remove Bolts: Use the 10mm bit rod to remove the bolts.  Remove the first bolt visible from the top.

4. Remove the other 3 bolts visible from the front side.

5. Remove the hidden bolt.  Now that you have removed the front side 3 bolts, you will be able to pull that plastic to expose the hidden lamp assembly bolt fastened to the chassis.

6. Shake and pull the the headlamp assembly.  Remember to remove three wiring harnesses connected to the headlamp assembly; a) The Bulb supply b) Motor, Parking lamp, Main Bulb supply c)  Indicator supply.

That’s it.  It takes just 5 minutes and 1 tool to remove the head lamp assembly from Getz Prime.

PROXIM ORINOCO 802.11 a/b/g/n

June 30th, 2011 No comments

Did you try this page for the driver?

Procedure for setting up proxim driver is given here:-

If you want to try an alternate device, use this list linux compatible devices:-

How to on Wireless networking:-

If there is a windows driver, you can use “ndiswrapper” to setup a Linux module atop the windows driver sys and inf files. Try this as well.

Fitting LED Strip to Getz Radiator Grill

August 15th, 2010 No comments

White (Blueish) LED strips with 3M water proof stickers are available for 300-350Rs/30cm.  These LED strips are pretty bright when illuminated and draws lesser power when compared to incandescent lamps.

Step 1: Open the Bonnet of the Car

Step 2: Identify the Parking Lamp + Head Lamp Positioning Motor Power Line

Step 3: Remove the Parking Lamp, Lamp Positioning Motor Power Connector

Step 4: Remove the Connector Shield to find the Power lines

Step 5: Find and Tap the Parking Lamp Line.

Step 6: Put the connector shield back on the connector
Step 7: Put the connector back on the Lamp assembly
Step 8: Turn on Parking Lamp; Hurray LED Strip is AWESOME.

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Another Automation Project

May 2nd, 2009 No comments

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January 4th, 2009 No comments

இப்படி கூட சோளத்தை சாப்பிடலாமோ…

சொல்லிக்கொடுத்தவர் இதோ..

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Weathering course

July 17th, 2008 No comments

There can be several problems with the weathering course laid on top in the terrace. I am facing a very peculiar problem with it. In my apartment, we are seeing water dripping out the roof via the parapet-roof joints several days after rain. Water oozes out via a crack that has formed at the joint of the parapet wall and the roof RCC. Also, the dripping is happening near the roof drain vents, which happens to the lowest area of the roof-top.

Generally while constructing roof and weathering course, masons leave an inclination of level towards a corner of the roof for the rain water to drain comfortably. In our case, we are seeing water draining through a crack between the parapet wall and the roof in the vicinity of the drain vent. Since it is near the drain vent, we were suspecting the thickness of the weathering course. As there is a forced inclination in the weathering course layer, the thickness of the course near the vent should be lesser than the other areas of the roof.

When we consulted with a civil engineer, he was giving a completely different explanation for the problem. He was suspecting the iron-oxide coated shells layered on top the weathering course. He was saying rain water might have gotten into the core of the weathering course through the gaps between the iron-oxide shells. The water thus gotten inside keeps the weathering course in soaked condition for a long time. Here the core of the weathering course behaves like a sponge to absorb all the water that seeps inside. Later, the water thus absorbed percolate to the lowest side of the roof slowly, which may take weeks time (like our case). Once the amount of water reach a significant quantity at the lowest side, it tries to escape somehow. In our case, the escape vent is a crack that had formed between the roof RCC and parapet wall construction.

So what is the solution to this problem? Should we take out the weathering course completely and redo from scratch? Should we be finding the source of the problem, the places were rain water seeps inside the core of the weathering course? Should we increase the thickness of the lowest side of the roof ? All these cannot be permanent solutions or they may not be easily doable. The
solution that I have is the following. Since the water collected is trying to escape, let’s give it an easy way to escape. Finally, we don’t want the core to be soaked. So we should be placing vent pipes just above the RCC roof level and be placed amidst the core of the weathering course at the lowest side of the roof. We know that water from all the areas are reaching here percolating for weeks. If there is an easy vent out like the vent pipe, the accumulated water can escape easily instead of dripping out of a crack. If we can find potential spots in the roof for more vent holes, we may very well preserve the consistency of the core of the weathering course for a long time. But that’s going to be pretty tricky!!

காருக்கு கவர் போட்ட கதை

July 7th, 2008 No comments

என்னிடம் Hyundai Getz கார் உள்ளது. அதற்கு கவர் போடுவது ஒரு பெரிய வேலையாக உள்ளது. என்னென்றால், தனியாக போட முடியாதென்று இது நாள் வரை நினைத்திருந்தேன். எப்போதுமே யாரவது கவர் போடுவதற்கு உதவியிருக்கிறார்கள். ஒரே ஒரு முறை மட்டும், நானே கவர் போட்டேன்; அப்போது நன்றாக காற்று அடித்துகொண்டிருந்தது. காற்றின் பக்கமாக கவரை தூக்க கவர் parachute போல பறக்க, அப்படியே காரின் மேல் சார்த்திவிட்டேன்.

இன்று, உதவுவதற்கு எவருமில்லை; காற்று கூட அமைதியாகவே இருந்தது. பல முயற்சி செய்தும் ஒரு பலனும் இல்லை. எனக்கே காமெடியாக இருந்தது. கவரை போடுவதும், அது விலகி கிழே விழுவதுமாக இருந்தது. யாரவது பார்த்திருந்தால் என்னை ஒரு கிறுக்கன் என்றே நினைத்திருப்பார்கள்.

நான் செய்த தவறு கடைசியாகத்தான் எனக்கு புரிந்தது. நான் கவரை காரின் முன் பக்கத்திலிருந்து போட முயற்சித்தேன். முன் பக்கம் தாழ்வாக இருப்பதால் கவரானது வழுக்கி விலகியது. சரி, ஒரு முறை பின்பக்கத்திலிருந்து முயற்சிப்போம் என்று போட்டு பார்க்க; அட இவ்வளவு எளிதாக கச்சிதமாக பொருந்துமா என்று ஆச்சரியப்பட்டேன்.

இக்கதையிலிருந்து கற்றுக்கொள்ளவேண்டியது காருக்கு கவர் போடும் போது பின் பக்கத்திலிருந்து தொடாங்க வேண்டும். முன் பக்கத்திலிருந்து தொடங்க வேண்டுமானால் யாராவது துணைக்கு வேண்டும்.