Tuesday, November 16, 2010

New Rig!

Sorry for not being here for a while, it was because i have just got a new pc.

Palit gtx460 786mb
AMD Athlon II x4 640 3Mhz (not OCed yet)
Asrock M4N78D with nForce 720a chipset
Kingston 4096 MB DDR3 1600Mhz
NVIDIA GeForce GTX460 Palit 786
Chieftec 650W 80+
Antec Three Hundred (5 fans total)

Thats a preety cool set-up for me, after being sticked to laptops for the last 8 years. What do you think?

PS. Electronics reports coming soon. Got loads of info :)

Friday, October 15, 2010

Adjustable power supply with LM317

LM317 is a cheap chip with 3 pins. It is widely known as one of the most basic microchip for adjustable power supplies. It is capable of working with 30 V and 1A current. However, it has quite a big voltage drop, around 1.5 Volts. Here is the pin out of the microchip:

LM317 comes in several packages, but TO-220 is the most convenient one, because you can easily get snap-on heat sinks for it.

The LM317 is not very good for "laboratory power supply" but for tests and troubleshooting it can go preety far.

This is the circuit that i have used to build one myself (note that this circuit is taken from original data sheet, but there is a mistake, pins 2 and 3 are swapped there. This is the right version!)
As you can see, there are only few components used.
1. LM317 microchip
2. 1uF electrolytic capacitor (The black stripe in circuit is anode (Negative; -))
3. 10uF electrolytic capacitor (The black stripe in circuit is anode (Negative; -))
4. 0.1uf ceramic capacitor
5. 240 (200 or 270 is also OK) ohm 0.125W resistor
6. 5K mono linear potentiometer
Optional parts:
7. Any LED.
8. 1k ohm 0.125W resistor

The pricing of all these things should be around 2$, or if you have resistors, capacitors and LED lying around it will be around 1$.
Sorry, but i wont be able to show you any photos if me making it - my camera is at the other town (im studying) at the moment, but heres a picture to see how small it actually is:
It is cheap, small, does not heat at all, but its hell useful! Try building one yourself!