I was just reading an article in the NYTimes about Russia, where there seems to be a new era of barter between companies, now that the financial crises has hit there too. So how about my PIC PWM design against your car?
That article mentions trading underwear for cars! And food! In itself it is an interesting idea to get rid of some stuff.
And you avoid taxes too :-)
I will, in a next transaction, sure mention it.
Say I get the LED light strips for a programmable PWM controller. Now, and that could create more business for others too
On a sunny day (Sun, 8 Feb 2009 03:29:08 -0800 (PST)) it happened snipped-for-privacy@aol.com wrote in :
Of course the PIC programmable RGB LED controller is working. It has been running for more then a week day and night. Wakes me up with LED light (has 5 programmable timers). I emailed the LED strip company about when I get the RGB strips I ordered, and they think I have those Wednesday. As I ordered cables too, they needed some time to make the cables.... And _that_ design is here:
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You need to add some power MOSFETS or transistors to the PIC output for the big LED strips.
If you were referring to the PIC switchmode design, yes that has been working for a while now, you can see some older pictures here: ftp://panteltje.com/pub/power_pic/
It delivers about 24 Watt with that transformer, that transformer is actually a mains interference filter :-). With 12V gel battery as input, it will do from zero to 25.5V output, with cycle by cycle current limit, LCD display of input voltage, output voltage, output current, output voltage setpoint, and time. It has the option of setting the output voltage with a simple pot, or doing it via RS232, all parameters including the current trip, soft start delay, max PWM angle, etc, can be set via RS232 and are saved in EEPROM.
Do I need to make the frequency selectable via RS232 and stored in EEPROM? A nice idea. I have to re-write the LCD driver as I moved around all output pins.
So, it is a hysteretic design regarding the voltage control section, with a cycle by cycle current limit, using the 2 analog comparators in the PIC.
How much power, and what voltage you use the PIC for, depends on the power stuff, not on the PIC.
Follow the postings named 'Universal PIC switchmode status report'.
Of course I will be more then happy to accept your car, especially if it is environmentally green, in exchange for the software.
If you really want to play with the software 'as is' (that is last night's version), provide me with a working email address, I will send it. It works.
The source asm has a pinout assignment listing, the pictures in the above link should show how to connect things, and it actually has a shot of the old diagram too. I will have to draw up a new diagram.
I have a bunch of new ideas about the soft that I want to try, not until I am
100% ready with all that, will it be on my site.
This one would make a very nice little universal lab supply.
On a sunny day (Sun, 8 Feb 2009 04:51:22 -0800 (PST)) it happened snipped-for-privacy@aol.com wrote in :
Of course testing was, and is being done. Do you think you can, with your pointless in comprehensive blabber impress anyone? Come with your own design. And write you own soft. I do not deal with you.
What do you actually want? A free ready made design delivered to you? Hope they deliver you a nuke with a working timer.
I don't think the guys at, e.g., Linear, National Semi, TI, OnSemi, IRF, etc. are too worried about it -- there are plenty of "plain Jane" switch-mode power supply control ICs out there there I suspect get relatively little market share as-is, since the market demand today seems to be largely for higher speed controls (at least >100kHz, and of course >1MHz is not at all uncommon anymore either) so that smaller components can be used.
It's amazing that in the same volume that the original PC power supply used to produce 65 watts, these days you can get up to 1kW!
The very first switcher I designed was in response to a reliability problem with someone else's design where, despite a LOT of forced air cooling, the components were still well above their rated temperature (although happily none of them had failed in the field, AFAIK). The original designer had something of a fascination with charge pumps, so he'd built himself a ~40W output power supply... that was all of something like 60% efficient! My design was a pretty standard pair of buck converters to generate +5V and
+15V... with the +5V coil being tapped to generate -5V [loosely regulated] as well. Efficiency was something like 88% (I did miss the 90% I was shooting for) but it was good enough to avoid any overheating -- no more active cooling was required.
That little 13.1V, 0.5A boost converter I posted pictures of a little over a week ago survived its temperature test without problems. Now I have to get back to some boring software... (Battery load testing, oh joy...)
On a sunny day (Mon, 9 Feb 2009 17:02:59 -0800) it happened "Joel Koltner" wrote in :
We had a linear regulator that I actually once build, 250 W, was heavy, not short circuit proof, and actually was killed a couple of times. I asked for a budget to design something better, and wow I got it! As I never did a switchmode before, and there was no internet, and no books on it in my possession either, I referred back to my old experience with TV horizontal output stages I designed many years before that... and spend quite some time calculating. I was worried about the transformer heat, in that time, and even now, I worry if a transformer gets hand warm, not like those cooking inductors you sometimes see in designs, so I used perhaps a bit bigger cores and thicker wire then the absolute minimum before melting the melinex isolation. Same for the diodes. What does not go out as heat is improving efficiency:-) And losses are I^R in thin wires in transformers. In many cases things do not need to be very very small, especially in higher power stuff, and as only a few are made, the component costs are nothing compared to all other costs, so why not have some extra margins. That is why I am not so impressed if somebody say that they have a switcher running at 1MHz with very very small inductors. And where is the limit? 100 MHz with new material semiconductors? Some RFI problem that will create, listen on the AM radio to my switcher. I am sure I can modulate that with some music, hey, all you have to do is use it to feed a class AB audio amp :-)
Yes, back to software too, got the LCD working on this single chip PIC PWM, but it needs some more work. Had yet to make a pin change.. to accommodate all signals I want.
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