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Once again, I stepped into the “prison” that has held me for almost 5 and a half years.

My cell for almost 2 years

My place of “Zen”

The always untidy cupboard

The workstation

Midnight power supplies

Living in the flattened world

View from window, the opposite female prison… perfect spot for peeping

Tomorrow, the final semester starts. Hopefully a peaceful semester…

Working with lab power supply is very common for engineering students as we need it to power up whatever project we are working on. However, there are times when we are unable to access the lab, and buying a lab power supply for personal usage might cost a bomb. Hence, I’ve come up with a much cheaper solution, which is to make a power supply unit from discarded computer (desktop) ATX power supply. With less than RM50 and a little modification, I can get a power supply unit with short circuit protection, high output current and highly regulated output voltage.

How can you do it as well? Read on…

Step 1:

Unplug the power cords at the back of your unwanted CPU, open the CPU casing and locate the power supply (normally a gray color metal casing box). Trace and disconnect all the wires connecting from the power supply to the devices and boards. Remove the power supply unit from the CPU casing.

Step 2:

You will need some extra components to convert this power supply into a usable unit.

1. Heat shrinkable tube (to protect unwanted conducting part).
2. A current limiting resistor, typically 330 ohm ¼ Watt (470 ohm may do as well).
3. A power resistor, typically 10 ohm 10 Watt (or greater).
4. An LED.
5. A toggle switch (to turn the power supply ON and OFF).
6. Audio socket/connector (actually any suitable socket/ connector can do).

If you are using audio socket/connectors, you may label each of the sockets with the respective output voltages using liquid marker.

Step 3:

If you are using a power supply from discarded computer, it is advisable to discharge it by letting it sit unconnected for a few days. However if you are using a new unused ATX power supply, you may straightaway proceed to the following.

Remove the screws locking the power supply with its cover. You’ll probably have a power supply similar to below:

Notice there is a bundle of long wires with different colors soldered to the board of the power supply. Each color represents different voltage level:

- Black = 0V (Ground)

- Red = +5V

- White = -5V (some power supply do not have this voltage)

- Yellow = +12V

- Blue = -12V

- Orange = +3.3V

- Purple = +5V for standby (normally not used)

- Gray = Power ON (output)

- Green = Turn DC ON (input)

Cut off these wires, but make sure you LEAVE A FEW INCHES for future use. Bundle the wire of same color together.

Step 4:

Here comes the hard part. You’ll need to drill holes on the casing of the power supply to mount the audio socket/connectors, LED and toggle switch.

1. Measure and mark the area to be drilled with a tap and hammer.

2. Use drill bit of appropriate size for component mounting.

3. Remember to drill holes for mounting LED and toggle switch as well.

There is no standard way to go around, just make sure you do this carefully and do not break the casing.

Step 5:

Mount and screw the audio socket/connectors to their respective holes on the casing. Next, connect all parts together as follow:

1. Connect one of the red wires to one of the power resistor’s lead, and the remaining to the socket labeled +5V.
2. Connect one of the black wires to the other lead of the power resistor, one black wire to a 330 ohm (or 470 ohm) resistor attached to the cathode of the LED, one black wire to the common terminal of the toggle switch, and all the remaining black wires to the socket labeled 0V.
3. Connect the yellow wires to the +12V socket, the blue to -12V socket, the grey to the anode of the LED, and the white (if your power supply have any) to the -5V socket.
4. Connect the green wire to the normally opened (NO) terminal of the Toggle Switch.
5. Some power supplies may have either a gray or brown wire representing power good. Connect this wire with one of the orange (+3.3V) wires; if not your power supply will not work.
6. Finally, make sure all soldered connections are insulated with the heat shrinkable tube and organize the wires accordingly. Mount the LED and toggle switch to their respective holes. If possible, fix the power resistor to the heat sink of the power supply.
7. Make sure there is no short circuit connection (beware that the casing of the power supply can conduct electricity). Cover and screw the casing back to the power supply unit.

There you go, a self-modified power supply unit for your project.

Works pretty well with my project

Please bear in mind that there are a few precautions you need to know:

1. This modified computer power supply is suitable for testing purposes and powering simple circuit, but its performance can never match a good lab power supply. Hence, if you intend to do more than just testing, it is more advisable to get yourself a lab power supply.
2. Line voltage can kill, so be extra careful when dealing with the supply power unit.
3. Make sure no metal dust fall into the circuit board of the power supply when drilling.
4. The power resistor is used to dissipate power when the power supply unit is not connected to any load. Hence it will get hot if the unit is turn ON. A good suggestion is to mount it onto the heat sink of the power supply.

Mounting power resistor onto heat sink

Hope this DIY information is useful to you. Have fun…

I remember last year, almost at this period of time, that I have some problems with the car of my age.

This year, there is no exception…

Before holiday, battery died off… so bought a new unit, burned my wallet.

After holiday, just two weeks of holiday, the same new battery went dry… gone through some troubles fixing it.

Yesterday, one of the tires was punctured by a metal nail… don’t know which idiot simply throw nail on the road…

Nonetheless, there are positive sides to all these problems I’ve gone through with this car…every of it allows me to experience something that I’ve yet to encountered.

This may sounds lame… but yesterday, I learned to change tire… |||-_-

p/s: This afternoon I just banged one of my coursemate’s motor. Luckily no serious damage incurred. I gotta admit its my carelessness… but just wanna say these few days are not my lucky days…

Today, I just realized someone from another part of the world is doing something similar to what I’ve been wanted to do for long long time, and he is doing it in a relatively large scale, yet doing it great! Once again, I am one step behind.

Does this sound familiar to you? On a very boring day, you are lying on your bed, brainstorming, thinking hard about your future and what comes next, being drown deep into thoughts…

… and “ting !”, a magnificent idea suddenly struck you. The more you imagine, the more you think it’s gonna work. It will make you become more successful, it will bring you from where you are to where you want to be… An “angel” on your left told you,  “OMG, that’s so cool !”

But at the same time, another “devil” on your right keep whispering, “You’re definitely not ready for it !“. At this moment, there will be four categories of people:

Type 1: Lose Before Battle

Back to zero, give themselves tonnes of excuses why they just can’t do it, ignore the “dream”, blame their own faith and get along with life.

Type 2: 3-Minutes Passion

Start taking little actions, gathering information, crunching books and journals… but the more they read, the more confuse they become. In the end, they gave up.

Type 3:  Chicken Little – The Sky’s Falling

Similar to Type 2, but they persisted. Take their sweet time gathering the “required information”, but always thinking that they are still not fully prepared yet. By the time they get started, they realized other people are already a hundred years in advance.

Type 4: Just Do It

People in this category will always tell themselves, “JUST DO IT!” They are clear with what they want to achieve in life and they know it’s not going to be an easy path. They have the great passion to try their best to reach their target. To them, their objectives of life is not a “should”, but a “must”. They do fall down in the journey but they keep themselves resilient. In the end, some may just achieve what they want… some may not, but still they know they have achieve quite a lot.

Often, we as human are thinking and worrying too much. Some are not satisfy with their life, they want to improve, but they do not want to take the responsibility. Some took little actions, but when it comes to obstacles they’d just give up. All these came from the same reason, they are not taking their goals seriously. They knew that without achieving their goal, they can still get along with life, their complaining life. They are only taking their goals as a “should”, but not a “must”.

Working hard for your goals might not 100% guarantee you achieving them, but not taking any action at all will always 100% guarantee you NOT achieving them.

Think for yourself, which category are you?