MAKE Magazine: Comments about Articles

PICAXE-08 = the new 555 !

this is the best comment i think i've ever read.

PICAXE-08 = the new 555 !

I'm only 12 right now but i've been fooling around with 555 timers since I was 10. I just got a PICAXE 08M yesterday, and its really awesome.

Source Code

I noticed that a few months back you stated you were almost done with the improved source code. I am curious as to whether it is available yet or not? Thanks a ton.

Several people have run these up to 400F, which is *WAY* over the maximum rating, so they will deteriorate over time. No one came even close to 5V @ 1A with a single candle (not even with a hacked candle.) You might want to read what Don Lancaster has to say about the efficiency of these things at http://www.tinaja.com/glib/hack68.pdf Some select comments from this page where you said people got it to work... >it was able to output just over 8 volts no load, and 2.5 amps at .1 v. Again at over 400 degrees f. >I supported the test rig over a heat gun and was able to get the hot side up to over 400 degrees f. ( I agree this is way too hot), however I wanted to see what the absolute highest output voltage I could get from them. >As I said I tested at temperatures too high for regular use >I think the 136 watt coolers I used will be useless at candle energy levels >I got up to a 4V, 200mA output by hacking the candle >I have done a little research and it appears that the TEC modules have an upper end of about 180 degrees C. >interesting idea, but I think the TEC modules are the weak link.

@Almost_There - if you look at the feedback on the article page which you linked to and all the folks who *did* get it to work i would say that it's likely you didn't build it correctly or gave up too soon without checking out the tips and hacks. you could email us, post in the forums, talked with other makers or documented your project. but it seems posting about this on our tv debut post is all we'll get. if you only built "one thing" it's possible that you're not an expert in making things like this. part of making is trial and error, not every project will work on first try. we don't expect anyone to "blindly trust" claims, but i don't think you gave this project a chance. if you're interested in getting the project working join in the discussion on the page.

Make is cool for creative ideas, but don’t blindly trust their claims.

I'm sorry that you feel that way, maybe you could have a look at the feedback from other readers that tried this project.

Are you really sure that it is a bomb?

You would be really surprised what the safe distance for bombs are, and what the explosive yield for something slightly smaller than a shoe box. Throw some ball bearings or nails into the equation, and your looking at a bad day for someone. Granted, the bomb is inside, and there are potentially things to hide behind. AFT states that a pipe bomb (about 5lbs of TNT equiv) has a building evac distance of 70ft, and an outdoor evac distance of 850 ft. A briefcase or suitcase bomb (about 50lbs TNT equiv)inside is 150 ft and outdoor 1850ft. Of course who knows what the explosive yield is for this particular situation. If it's slightly smaller than a shoe box, let's say 17cm x 12 cm x 35cm " or 7140 cm^3, and it's C4 with a density of 1.63g/cm^3, so we are looking at something that weighs about 11kg (24lbs). C4 is 1.34 times as explosive as TNT, so we're looking at about a 32lbs explosives. Whose got the time to figure all this stuff out in this situation though? :0) Good luck with the challenge to all.

Making Biodiesel

The process of making biodiesel requires a permit from any city or county. In addition to the fire department, a building department will require a change of occupancy for the manufacturing of biodiesel since manufacturing is the process (or use). A change of occupancy from a residential facility to a manufacturing plant (the garage in most cases) is not worth the end cost associated with such a change. The process includes product that can deteriorate bone, in addition to, waste products that require permits to have and dispose from any Certified Unified Program Agency (CUPA) and the local fire department. Although a vary creative idea, making biodiesel in the garage or backyard requires permits and fees that outweigh the benefit of lower cost diesel. Thanks for reading, Tom

my post-build tips

some quick tips, most likely to benefit utter n00bs like me. (i've built from kits, but that's about it.) * if you're having trouble finding a board for this project, consider using perfboard instead. i learned a lot more about the circuit's design that way, and didn't have any insurmountable problems, even though it was my first time using it instead of a pcb. * i added two additional 3-port term blocks: one for the programming port, and one for the 10k pot. this was a big improvement, and an easy mod, since i wasn't using a pcb. * i suspect others have had trouble finding a 250uf capacitor - i certainly did. i traded a 220uf - much more readily available, at least where i live - without any noticeable difference. * i also traded out the multi-turn pot for a single-turn pot - it's just a little simpler for volume control. hope this helps someone - most of all, though, don't be intimidated by not having a board! perfboard is easy enough to use, and gives you a lot of flexibility to make changes if you want to.

PCR thermal cycler

Grr.. no preview... The UK / European supplier guide is UK Component and Tool Suppliers by Ian White, G3SEK.

PCR thermal cycler

For replacement of the original IRF5305 P-channel MOSFET:

On Semi's part #: MTP50P03HDLG
DigiKey part #: MTP50P03HDLGOS-ND
Mouser's part #: 863-MTP50P03HDLG
Jameco P/N: 879220
MTP50P03HDLG Datasheet from On Semi

For the N-channel MOSFET (originally an HUF75321) International Refectifier (IR)'s IRL7833 (IRL7833PBF) in TO-220 packaging:

DigiKey part #: IRL7833PBF-ND
Mouser part #: 511-STP80NF03L-04 (is a STP80NF03L-04 which should be compatible)
IRL7833 datasheet

For European component sources read

Are you really sure that it is a bomb?

Absolutely true. For all we know it could be a small super computer, or a wondeful motion triggered modular synthesiser. :) But it it IS a bomb, by some odd chance, why it it such a big deal, you're the only one on the floor, and the bomb is only the size of a shoe box. Now, assuming that it isn't a nuclear device or has some rediculously powerful explosive in it, then the bomb really isn't that dangerous. The bombs that destroy office buildings are the size of entire vans, and even then they normally don't destroy the entire building. So personally, I'd just drive out of the garage until I can get cellphone reception, and call the police, and tell them that there's a bomb. Hey, you could even cut out the risk of sending a dangerous signal, and just try to run up a floor or two in the parking garage and hide instead of having to risk your cell or car unlock signal set off the bomb

styrocutter transformer

I used a battery charge maintainer. It puts out 2 amps in either 6 or 12 volts. Less than 20 bucks at Walmart. The 6 volt output worked pretty well.

Portable igloo cooler block? plus solar power

I recently acquired a couple cooling blocks from EPO with a heat sink and cold sink/shoe with a unmarked peltier cell in it( checking the homepage for EPO told me it was 12v/5amp). how would I go about using it for this project? another note... My dad looked at this project and thought that a solar-heated (heated wit hsolar light reflected onto a surface by many mirrors; similar to a supermarket scanner) seebeck would be a neat- and environment-friendly way to produce power. I would like to know id this is possible, thanks! ~~--Bladebaka