zking786

As for question 1, I don't think both transistors are not mounted on the same metal heatsink. I have them mounted on a single breadboard, though. They are not touching eachother. As for question 2, when I do a diode test using the multimeter, I get a low value (001), so the transistor's case and the metal mounting seem to be joined. Also, on the tantalum it has + and - in small print. I believe I've plugged them in correctly, but was wondering if my poor soldering skills could have blown them (that is, the extensive exposure to heat). Should I post pics of my actual circuit? Would these help?

Well, assuming I hooked it up correctly, what could be wrong? Also, is there a problem with the schematic, or should it work? Lastly, could the tantalum capacitors be blown (due to the heat of soldering)? What could be blown, aside from the transistors?

It seems I've gone through 6 Transistors (should have used fuses!) with my circuit. Can someone explain to me why it's not working. Here's the diagram: http://www.i4at.org/lib2/inverter.htm Here's what I've used in the circuit: I've used resistors with 5% tolerance. The transformer is 300W The diodes are FR155 (should be equivalent to HEP 155) I have used heat sink to secure the transistors (so as to avoid burning them out) and confirmed they work before running the circuit I've observed: A small spark at the battery's mains when I connect it, and thereafter it no longer sparks (something's blown thereafter). The current voltmeter on the output end showed 10VAC briefly (like for half a second) the first time and then nothing. The Base-Emitter junction doesn't pass on either transistor (therefore it must be blown) The Base-Collector passes on both transistors, however, one yields a diode test value of around 500 and the other 001. I wonder why. Can someone please help me by explaining my obervations?

Cool! Well, it would be interesting to study the physiology of any living organsim!

That's very interesting. Also, how do they detect the presence of CO2? It would be interesting to study the physiology of the mosquito's various sensory receptors.

About how many hours do I need to run the setup? Say I'm pumping in .75A at 17V, how many hours till I will get the green solution you speak of? While I have Dilute N/10 HCL, what other cool experiments can I perform?

Anyone know what the components of sweat are? Which one, in particular, attracts these mosquitos? Are males attracted to the same things as females? BTW, thanks for all the answers!

So the FR155 is 1N5826? The naming scheme seems confusing. Is there any general system?

Is the FR155 equivalent?

YT2095, you seem to know what you're doing . Perhaps you could explain, in basic terms, how this circuit works. I'm completely confused! Also, I forgot to ask, could the tantalum capacitors be blown also? I hear they're supposed to be able to handle higher temperatures. Lastly, when I was buying the diodes they sold me FR155 diodes, saying they're the same as HEP 154. Is this correct? I'm starting to doubt everything these guys told me! To add to the above list of questions: Which ends of the circuit draws the most current? I'd assume I'll need thick wire for the part that connects to the battery. After that, when will I be able to use thin wire in the circuit?

YT2095, you seem to know what you're doing . Perhaps you could explain, in basic terms, how this circuit works. I'm completely confused! Also, I forgot to ask, could the tantalum capacitors be blown also? I hear they're supposed to be able to handle higher temperatures. Lastly, when I was buying the diodes they sold me FR155 diodes, saying they're the same as HEP 154. Is this correct? I'm starting to doubt everything these guys told me!

Thanks YT2095. I mistaked the connectors because I'm a beginner . See, the guy I bought the part from told me the case is the base NOT the collector. I guess that explains why I got a small amount of voltage at the beginning. Also, about the wires I'm using in the circuit -- how thick must they be? I've used really thick wire for the mains (in and out), but thin wire for the interconnections. Is this ok? How thick in diameter do you think is safe. Also, the wires must impose some resistance to the circuit. Won't these throw off the conversion?

I found the diode, but when I assembled the circuit it won't work . See http://www.scienceforums.net/forums/showthread.php?p=265913#post265913 for more info on my problem.

Okay, so I've been designing an inverter. I've purchased all the components and designed the circuit as specified by this website http://www.i4at.org/lib2/inverter.htm Unfortunately, it doesn't work. Possibly for these reasons: 1. Initially, I mixed up the base and collector of the NPN transistor (2N3005)in the circuit and ran it. I didn't hear any popping and didn't get any voltage out of the converter. Though, at the beginning I got about 8V from one of the terminals and the center tap. Maybe this blew the transistor? 2. I mistakely broke off one of the terminals of the transistor and had to resolder it on. Thus, I might have overheated the terminal and transistor. 3. The tantalum capacitor was soldered to the breadboard (since it was moving around) and might have overheated and burned out? Or maybe my switching the transistor's two terminals blew it? Any idea which of these actually happened? What could have gone wrong? How can I fix it? I know the circuit was constructed as specified by the inverter circuit. Please help!!!

"When I hook the capacitor to the battery and connect a diode to prevent backflow, it only charges to 1.4V (approximately the voltage of the battery). Do I have to use an inductor? Or am I doing this incorrectly?" So, any ideas?

Neither the 1N400x or 1N540x series will work. Why not? Excuse my inexperience, but why won't they work? What's a stud diode? How does it differ from a traditional silicon diode?

As you must know from my other thread on inverters, I'm trying to build one. I'm having difficulty in finding all the parts, though. Using the simplest inversion circuit I found (http://www.i4at.org/lib2/inverter.htm), I have purchased all the supplied I need except the silicon diode of model HEP 154. I've checked all local stores and none seem to have the exact part. I've been told 1N4004 is can replace this part and should work by some. Others have said 1N4007 is needed. Due to my inexperience, I'm not sure what to get. I want the circuit to work well, but can't find the right part. From my understanding, the purpose of these diodes in the above-linked circuit is to direct current one way. I don't see how using a rectifier diode which can handle a really high current (above the required 15A) can hurt anything. Can someone confirm or reject this notion?

Thanks for the confirmation, YT2095. For clarification, I've been using a 12V charger (gives about 17-18V pd). Maybe that's why I didn't notice the smoke-like liquid migrating from the cathode to the anode -- it just happened too quickly. Any idea what's going on? If a copper salt is formed, why doesn't the copper chloride solution produce hydrogen at the addition of Al?

For some reason the described experiment didn't work. I used two different copper wires and plenty of EMF, but still didn't get a green solution. When I added Al, I didn't even get a reaction. I did, however, find bubbles at the cathode. A black coating formed at the cathode and a white/clear one formed at the anode. What happened?

I'll try the HCl method you recommended. Could you also tell me about the alloy-based methods? I'll be going to a large chemical supply store and can probably either purchase or create the alloys. Also, what do you mean by OTC?

That's interesting, I heard that if you use a carbon electrode (the type used for welding) you can create CO2 gas and H2 gas. Anyway, what other inexpensive electrode combinations would you recommend if I'm trying to produce hydrogen only (no other gases)? On a side note, woelen, you seem to be fairly experienced in inorganic chemistry. I was wondering if you know what type of alloy or compound I could deposit in water to safely produce lots of hydrogen inexpensively. I've heard of a nickel and sodium based solution, but I can't remember the name. I've seen an experiment where a guy dropped a pelet of some alloy into a container of water (not electrolyte solution) to produce lots of hydrogen. He had said that the alloy was really cheap--I just can't remember the name! Any ideas?

That makes sense. So the typical generic transformers don't change frequency, just voltage. Thus a 60Hz appliance will probably run on 50Hz power and vice versa. So they don't really bother too much about the frequency in everyday appliances, right?

When I hook the capacitor to the battery and connect a diode to prevent backflow, it only charges to 1.4V (approximately the voltage of the battery). Do I have to use an inductor? Or am I doing this incorrectly?

Oh... so the chopper is at the core, where the coils are wrapped. Also, I'm trying to create a UPS (connecting the car battery to the inverter to produce back up power). I have a couple of computer power supplies, though. But don't these take 240VAC and generate 12VDC? I need to do the reverse. Or is the power supply I'm discussing not a 'UPS'?

Thanks for the help! What about if I want to produce hydrogen gas only (no chlorine gas or oxygen, just hydrogen). I thought using aluminum electrodes would allow me to create an oxide of aluminum and hydrogen gas only. How do you know which gases are created at the electrodes? Is there a chart you're using? Thanks for the answers.