Dazza

Thankfully no skunks. We do have bats, their called flying foxes/fruit bats fairly large, we do have a few colonies here in Bundaberg, and they litter the sky late in the afternoon. When I lived up north Townsville area, when I was very young we use to go camping at a place called Rocky ponds, when the bats came over late in the afternoon you could not see in any direction, where they started or ended. They were so thick at times it would go dark, and I'm not kidding. My father would take a couple of shots at them with a 22 calibre rifle, as soon as you heard the rifle go off, the bat that he was aiming for would circle the bullet :o. That's some mighty fine radar equipment 8). I am a big nature fan, and I would love to be able to listen in on the bats ultrasonics, I hope you are planning on posting that circuit on these forms somewhere ;D.

Oh yes, you would fit in nicely here audioguru 8), you have the humour that is important, you just have to learn the lingo. Then I could give you all my failed projects, for you to fix for me ;D. That would give ante a well deserved break, from helping me with my projects :P. Yes it does take a little getting used to, being upside down and all ;D. I have seen so many car batteries, wasted from not checking the water/sulphuric acid level. They can dry out very fast in the Australian climate. And these so-called sealed led acid car batteries, the only difference I can see is that you can't take the caps off easily to check the water level, I think it's just a con, so they fail sooner >:(.

Well I wasn't to sure about your suggestion of removing D1, but I tried it anyway ;D. You're answer to(what happened without D1?) Well the Hall sensor didn't like having high voltage shoved up its B_M 12v that is ;D. There is one more Hall sensor left at Dick Smith, I'll have to be extra careful with this one ;). Well I was quite happy with myself, that I managed to get the circuit to work as well as I did, without destroying the Hall sensor. And it took one Swede half a world away to destroy it on me ::). Bad Swede, bad Swede. Just kidding ante ;D ;D ;D ;D, I'll be getting another Hall sensor shortly, and then I'll check and see what the output is from U1 and post the results. Yes the travel in relation to the magnet on the Hall sensor, seems to be pretty good/usable, I am using a fairly large magnet to influence the Hall sensor, so I am not sure how the response will be with a small electromagnet, it should be ok, in regards to the electromagnet, can you offer me any guidance here ante. Basically it's just many turns of wire wrapped around soft iron, I'm just not to sure how I would supply the voltage to it and control it :-\. I had a look at the website for where you work :D, I can see what you mean when you say, you need a drink on Fridays after work. Take it easy ante 8).

That's right dunny, it was also known as the Thunderbox. And yes we to now have running water, and a new gizmo called a shower. Now we don't have to saddle up the Wallabies to hop down to the creek for a bath. It's amazing the technology these days :o. Audioguru, it's good to have a laugh every now and then, cheers ;)

Back in the early days many many moons ago, we used a stick with some cloth wrapped around one end, soaked in oil so it would burn, it was called the torch, it helped us find our way to the Dunny without tripping over ;D. Then it was replaced by the light globe, so we also call this a torch because it also helped us find our way to the Dunny 8). So what happened to your torch up there, can you still find your way to the dunny, with just a flash? ??? ;D ;D ;D ;)

Find yourself a nice big bench and then put everything on it ;D, when you run out of room by another bench or put up some shelves . Make it up as you go ;D. There is snapshots of members work benches somewhere on electronic lab.

Audioguro, are you sure you're in the right trade, maybe you should consider stand-up comedy, you have posted enough good material on these forms to get you started. ;D ;D ;D ;D lol

Well with some trial and error, actually it was all trial and error ;D, I came up with this circuit. I managed to get an output from 0.56V TO 10V. With the addition of C1, I seem to get a nice smooth rise and fall in voltage. I can't work out how to get rid of the last 0.56V. how are we looking here ante, am I on the right track here 8) ;D.

Sorry ante, I should have mentioned that I was using the (UGN3503U) Hall affect sensor ::). That's why I only supply the circuit with 5V ;D.

Steven, I posted a short clip a while back, of one of my experiments :). It's on page 1, Schematics Variable current 12v 60A to 0A under circuits/general request (Hydrogen_7.zip)

Well I tried this circuit that I posted with a 5V supply, and it worked in a kind of fashion :-\, I'm not to sure where to take it from here. I didn't have the IC specified so I tried a few different ones that I had lain around. With a LM358M I got 2.43V and then the voltage steadily reached 3.72V with the influence of a magnet on the Hall affects sensor. I'm surprised it worked at all ;D.

Sounds like you're having fun playing with hydrogen Steven ;D, you wont see a flame as hydrogen burns clear, this is one of the dangers of a hydrogen flame, you can't see it but you know it's there when it burns you :(. Hydrogen ignites violently although it is difficult to ignite as it is leaving the solution because hydrogen dissipates into the atmosphere very rapidly, this is one of the upside to hydrogen in respect to leakage.(there is a lot more hydrogen being produced then you may realise) If you want to ignite hydrogen with some pops and bangs and flashes at night I will give you one of my recipes 8). For the electrodes use stainless steel, steal a couple of knives forks etc, from the kitchen. Do not sealed the container leave it open. Users sulphuric acid/battery acid as the catalyst, you'll have to experiment a bit to find a balance between, the electrodes spacing, the amount of catalyst and the amount of current voltage that you can supply. Purified water is best and don't let any other materials into the solution except for stainless steel, this way the solution will stay relatively clean. Once you have a good reaction happening with a steady flow of hydrogen and oxygen, add some dishwashing liquid the tiniest bit at a time, this will form Bubbles of hydrogen and oxygen that you can ignite with a flame, be sure to shield yourself from the solution when you do this, as acid may splash on you from the Bubbles as they ignite. I use 12V and around 6A, it worked really well very loud bangs :o.

Thanks John :).

Either one of then will be fine thanks. (1) NEC IRELAND D8749HC (2) DQ2817A-300

Yes ante, membrane with a magnet attached to it was the first way I thought of. Then I realised it would be much simpler to attach an electromagnet and sensor, to the moving parts of a regular mechanical pressure gauge. I think an electromagnet would be better for fine tuning and alignment. The Hall sensor that you suggested is not available from Farnell :(. Can you offer me some guidance in choosing an alternative Hall sensor :-\, what characteristics are good and what is not, for this application. Shovelling snow doesn't sound like a good thing to be looking forward to, for the Christmas break >:(, the Aussie Christmas of looking for a shady spot away from the blistering heat in the backyard, to relax with a few cold beers sounds much better 8). Although my partner would disagree, she has always wanted to see a white Christmas. Eventually you wont have to shovel all of that snow out of your driveway, some of it can go into the tank of your car to be melted for fuel ;D. Well that is another problem that I haven't thought of until now. I have been told about sump heaters? I'm not too sure how they work, I would presume you would have a heating element in your sump, that would be connected to the mains to prevent your engines from freezing. I guess you can add an extra heating element in the reactor, and another in the fuel tank for once the engine is running.

Yes ante, I will have to put together what I have on the drawing board, and then comeback to this circuit once I have some answers to these unknowns. I am happy that we at least have something to start with :). In my endeavour to make my own cheap pressure transmitter I have discovered Hall Sensors. And yes here comes the questions ;D. There seems to be a few different types, switch and sensor I am assuming the sensor type will give a varying response influenced by the strength of a magnetic field, I wont have much problem putting together a device that will give a mechanical response to pressure, the problems that I have found is the strength of that response is very poor, not enough to drive any potentiometer or a trimpot that I have found. Have you had any experiences with Hall Sensors, if so can you think of a particular one that could be suitable to try :-\. ante, if any member of electronic lad, hasn't seen one of Stevens circuit that he has posted, I think they must have their eyes closed ;D ;D. Yes I do want to make as much test equipment as possible myself, much cheaper and I can learn a lot by making it myself 8). Silicon chip magazine gives away a Peak Analyst LCR Meter every month, for the best electronic circuit ideas. I didn't realise just how good that little device was, until I checked out that link you posted :o, I think I will have to add it to my Christmas list.

Ante, I think this is brilliant 8), looking at your circuit I can sort of see how it works, and the way you have explained how it should work I can't see any downside. My only problem is that I usually search the Internet for the kind of complete working circuit that I need, and then try to modify it width trial and error to work the way I want. If the components values were chosen near enough for the circuit to work I could take it from their :-\. The amount of time and effort I have put into learning electronics I should know a lot more than I do :(, I probably should take this as a sign to give up. fortunately or maybe I should say unfortunately, I don't give up easily and I have a near endless supply of determination ;D. I think once I have this circuit on the drawing board ready to put together, I'll have a break from this project for a couple of weeks and comeback with a clear head and a fresh approach. In the meantime I desperately need some basic test equipment especially a MOSFETs tester, which I think a failed MOSFETs is the problem with the PWM that I am using now which has failed. I am thinking of trying to put a transistor tester, Zenner diode tester and a MOSFETs tester, into the one unit :o. I think this could be handy to have three separate pieces of test equipment in the one unit. Everything has been against me lately ante :(. We've been having frequent storms coming over, usually when I want to use the computer or connect to the net, and the error problems with electronic lad as well as errors with my own computer, is a real pain. The upside is I have had time to do some scavenging, and I have found a lot of handy electronic bits and pieces. I found a heap of old circuit boards I don't know what they're out of, but there is a lot of goodies on them, I've collected 18 12v relays which farnell list as $37 each, and I think there is about 10 24V relays there as well, which aren't the sealed type relay which have some water damage, but still work perfectly, and plenty of IC's and transistors of all sorts. There is also a couple of strange looking components that I have no idea what they are ???.

Yes ante, this is what I need and I do agree it is complicated :(. As soon as I read the description of this circuit, I realised it worked exactly the way I wanted, controlled the slew rate rise and fall, and then I thought damn it's complicated. You are certainly coming up with some good ways of achieving the effect that I am wanting 8), although I think what you are suggesting will have a stepper affect is this right? If so it will basically create some of the effect that I'm trying to avoid. Adding the ability to control the slew rate rise and fall, will have a positive effect on a lot of the system, one big positive is being able to reduce the amount of hydrogen stored in the hydrogen line, and another is to reduce the effect of horsepower being suddenly drawn from the engine especially if the reactor is demanding higher current, and I am not too sure how the alternator and regulator system, will appreciate being kicked on a fairly regular basis to respond quickly, especially when relying on the idea of using capacitors in the alternator regulators system. I can see that I am likely going to need something to maintain the revs of the engine at idle, if the alternator is drawing too much load from the engine, probably a solenoid but this sort of thing can be sorted out later on down the track. But this slew rate control/dampening effect that I am wanting, will be needed very early in this project. I did find this IC,(DS36C280 Slew Rate Controlled CMOS EIA-RS-485 Transceiver), I am unsure if I can use it, or how to use it. DS36C280_2.pdf

asciiwhite, that is very helpful thank you :).

Ante, here is the circuit description, I had to zip it because it's a word document. CIRCUIT_ALLOWS_SLEW_RATE_CONTROL_WITH_INDEPENDENT_RISE_AND_FALL_RATES.zip

Ante, slew rate control I think is what I'm looking for :), I found one circuit and I'm still searching for more, they seem to be a bit scarce :(. I am not too sure about this one, I'm a little confused on how to put it together. Maybe there is a better circuit to be found. The safety device that I'm leaving to another time, is because the test engine will not be in closed and the risk will be minimal at this stage. Yes ante, I have no doubt you know what you're talking about, I wanted to be sure I was getting it right that's all ;D, the right name for a particular device.

mixos, I am pleased to here your are doing your best to resolve this unfortunate problem. Thank you from Dazza.

I found some old circuit boards at a scrapyard I'm not sure what their out of, but sure do have some useful bits. Including some stud Mount diodes which I would really like to find out their voltage and ampere rating. This is what is written on the diodes 86 40 Z322402 1-805 thanks in advance :).

ante, pressure sender switch, to me and others I have worked with in the mechanical area, means when a temperature or pressure reaches a certain point, it turns on or off(receives no change in State until a certain point). And a pressure sender, means it sends a signal corresponding to the temperature or pressure that it is at. So I should be saying, pressure transmitter? Instead of pressure sender. One, pressure transmitter will control the PWM. so it's varying voltage that corresponds to the pressure in the hydrogen line will control the power to the reactor via the PWM. I will also need another pressure transmitter, as a safety shutdown, to detect whether the pressure is too high or too low, and another safety shutdown to work in the same way for the reactor chamber, this is in case the one-way valve between the reactor chamber in the hydrogen line became blocked. I like the way you are on the ball with safety ideas ante, I also have a mechanical over pressure release which will also release an enormous amount of energy, if the worst was to happen and there was an ignition spark within the chamber. As for where to release the hydrogen in such an event. Interesting enough it is extremely difficult to ignite hydrogen once released into the atmosphere. If you were to release hydrogen and turn off the source, and quickly try to ignite it,it is very very unlikely it would. The reason is, that hydrogen dissipates into the atmosphere extremely fast. If it was LPG leaking from under your hood, the danger alarms should be ringing. But just to make sure an electric fan can be used, that can be switched on in the event of a shutdown to help dissipate any released hydrogen,or the safety shutdown could be linked to the existing cooling fans of the vehicle on the radiator if fitted. There is another safety device idea that I have, but I am pretty sure this would be very difficult to put together and best left to a later time. The basic idea is although I do not want to attend it at this stage, is to compare the difference between RPM, hydrogen pressure and current being drawn by the reactor. At any given RPM the other two variables should correspond, within a certain degree range of error. For now ante for experimenting, I can get away with one pressure transmitter, in the reactor chamber only water here, I won't use a one-way valve so the pressure in the hydrogen line and in the reactor will be the same, later on I will have to come up with the cash for a proper sender transmitter designed for hydrogen, these are available but cost an arm and a leg. Sorry for sending you astray ante, that sure is good for off the top of your head 8), I'm pretty sure I can use that circuit with the heat exchange system :). You are pretty much on track, which is a little surprising considering how bad I am at explaining things :-\.

Yes I'm having these problems as well, I was thinking it was my computer playing up, considering its practically from the dark age ;D.