Tuesday, February 24, 2009

New Digital PWM Controller for HHO Hydrogen Cell...

My analog current controller (not blogged) has been working okay thus far. As always, some of us are never satisfied unless they see some LEDs blinking somewhere to reconfirm that the unit is working. So I embarked on making a current controller that's digitally based so that I could display some functions as well as eliminating the need to open the casing to set the current, etc.

This new controller do that. It displays the line voltage, the current draw, the PWM frequency, the current limit and the cut off voltage. Setting the current and cut off voltage is done by a single switch brought to the front of the unit.

Once set, the unit will try to achieve/maintain the set current by varying the PWM frequency. It will also monitor the line voltage and if the voltage drop below the setpoint, it will switch off the PWM. Photo show the test unit displaying the line voltage... kewl... don't you think... :-)

Thursday, February 19, 2009

CHEAP, effective, convenient SMD container

All electronic hobbyists know surface mound devices are the way of the future... small, cheap but really pain in the ^%*& for homebrew and DIY. But with enough patience and courage, no mountain too high attitude, it can be done...

Because the SMD are so tiny, I needed a way to store them... After much searching for suitable solution, I came across the 'Weekly Pills Organizer' at a local store that cost only RM5 each. Bought a whole bunch of them, labelled using self adhesive sticker and now neatly stacked near my workbench...

There are several type of the weekly pill organizers. Get the one like mine below for the following reasons.

  1. It's cheap, translucent and not pre-printed. Simpler for you to print and stick your own.
  2. The unit comes with the large storage box. You can group your SMD together; resistors, capacitors, etc... Also, it serves as double-lock so that it is more robust... less likely to open by mistake...
  3. The smaller unit is detachable. Makes your live easier when you want to take the devices. If you drop it, only the 3 containers are affected... not the total 21 :-(

Tuesday, February 17, 2009

CAUTION: To friends using the PIC16F88

Just a short cautionary note to all friends using the Microchip PIC16F88 chip.

If you use Internal Oscillator as your system clock, please avoid using the MCLR pin as input, eventhough PIC16F88 can be configured that way. The reason for this caution is that, once your program the PIC, it is almost imposibble to re-program it. The PIC will start executing once it's powered and that will some how cause the programming timing to go haywire.

Do take note.
I've wasted two PIC16F88 before looking this problem up on the 'net :-(

Electronics without schematic...

Eventhough you don't understand anything about electronics, you can still appreciate the outcome... for this project, you don't need to know the difference between resistor and capacitor and transistor and translator... just some glue and lot's of creativity... image from www.sparkfun.com

Tuesday, February 10, 2009

Blink Blink Revisited

For those who got good memory, you may recall this project I did earlier... it had gone through multiple iterations... from LED replacement to several code changes. The most recent is the request to change from the large LCD based interface to a smaller unit... test unit is done, awaiting test with my friend...

The original interface...

Newly designed interface... just LED to echo the state of the LED banks... smaller box with RJ-11 connector... can just use any 4-wire telephone cables... :_) Overall size about 4x3 inches...

Tuesday, February 3, 2009

Icom OPC-478 Programming Cable

Hello all,

I've had the Icom IC-2200 2m transceiver for the past few month for my base unit. I haven't been using it for a long while as I seldom QSO when I'm home... too many other things to do... Lately several new repeaters have been on the scene and as always... read as being lazy... I take not effort to update the IC-2200 frequencies.

Lucky for me, there's another station who got nothing to do other than amateur radio and, better still, he is also using the IC-2200... read as cloning time... Though the IC-2200 allow cloning using a simple stereo cable, I wanted to edit some of the frequencies before loading it on my unit... the hunt for suitable arsenal begins...

To do what I wanted to do... three things are needed... 1) The Icom OPC-478 programming cable, 2) The right software, and 3) a USB to RS232 convertor since my PC doesn't have built in serial port. Found the circuit for OPC-478 equivalent on the net so I got that done. Found the right software... somehow :-) I also got the USB to RS232 convertor

I'm ready right? Nope, as it turns out the USB to RS232 convertor had some compatibility problems... It was detected by my OS but fail to work with the OPC-478... Lucky, I had another converter (another brand) lying around and that unit worked... Conclusion, get USB to RS232 converter that uses the FTDI chip... it seems to be more 'compatible'... how to tell the different? You can't... most packaging do not specify the chip used... :-( Just try your luck... btw, the one that worked was molded with dark grey plastics... the one that does not work was molded using blue plastics... don't know if that helps...


The screenshot of the Icom CS-2200H software...