COP 17 Heater | Rosemary Ainslie

[poynt99]

Goodness Rose

I'm sorry to hear about your poor internet service, it would certainly drive me crazy.

However, for the 15 minutes or so you took to write all the above, certainly you could have written one or two sentences to appease my simple request. Why assume that I was asking for dllabarre's benefit alone? I am asking for my and everyone's benefit. Why are you making this so difficult (yes indeed you are)? It is a simple question.

Please clarify your response in general to the requirement of the inductive resistor's specifications for your experiment.

OR, as put previous:

Please clarify your response to dilabarre regarding the resistance and inductance value of the load resistor. (To benefit ALL here).

Thank you.

.99

[witsend]

Harvey - many thanks for the translation. Would never have known how to do that.

[witsend]

Poynt - goodness. No discourtesy intended. Let me explain my problem. I get my link to the internet through Mweb - who, in turn, get their link through Telkom. Telkom are the monopolists and they simply contract a few service providers to 'share the load'. But Telkom have a contract with all their clients that, in the unhappy event that they deliver sub-standard speeds or if they break down - then no-one can claim from them. They're only required to give of their best and that best has never been 'defined'. My personal conviction is that they deliver sub-standard because that way they can get the best return. We're still, essentially - third world - but with first world pretensions.

Why all this is relevant is that - at the moment - it takes 5 minutes to change pages and 10 minutes to post - and somewhere between 5 and 10 minutes to log back onto the main menu here. So. If I were to satisfy your requirement - then to get back to that page and then post would take upwards of half an hour. Add another 10 minutes to get back to this thread. I'm afraid my patience is not equal to it. But if you'll wait until our time speeds up - which could be anytime between now and next year - then I'll gladly oblige. Meanwhile, please accept my apologies - on behalf of Mweb and Telkom. This is the message we get - droning on and on- every time I phone to try and log the complaint "Mweb apologises to customers. The connection to all overseas facilities are slow. Telkom are looking into the problem'. I eventually managed to speak to someone this morning to vent my anger and had the dubious satisfaction of raging at some poor innocent at the help desk. But personnel there are innured to all such explosions from the public. They've been trained to answer politely but ignore the problem.

If you've read through all that - then you'll have discovered some of the conditions that we're subjected to. It's exasperating. That's a mixed emotion - because there's no 'rage' emoticon.

EDIT BTW I'm reasonably certain that dllabarre can speak for himself here - and I don't think there's a need to clarify the situation beyond what's been said. Certainly I can't add to it. I don't have the necessary data.

[poynt99]

Rose,

This one time please pay me the same courtesy I have paid you several times when you ask me to post links and repost information etc. I'd rather not go searching when it would be much easier just to state in one sentence what you meant. Thanks.

I didn't understand your response.

Please clarify your response to dilabarre regarding the resistance and inductance value of the load resistor.

The video is coming fine.

Thanks.
.99

[witsend]

Hi Poynt. I've already referred to this - on the 02nd or thereby. What's missing on Harvey's and Aaron's test is the required level of heat. Aaron has anomalies but not at the level that our own test pointed to.

The only thing that has been successfully replicated, in fact, is Fuzzy's, of Aaron's test.

How are the videos coming on?

[poynt99]

Inductive Resistor Inductance Value

Just noticed this post. Sorry dllabarre. We're hoping this is the missing variable because nothing else seems to work.

Rose, could you please clarify what you are saying here regarding the inductive resistor?

Much obliged,

.99

[witsend]

AND [/B]8.64 micro Henries is what's important in reproducing this resistor to maintain the circuits performance?

Thank you,

Just noticed this post. Sorry dllabarre. We're hoping this is the missing variable because nothing else seems to work.

[poynt99]

Actually, this is the most accurate schematic I'm using. The only difference at the moment is different cap values on the timer circuit.

EDIT - actually, I'm not using 2 separate "shunts" for power measurements.
I have neg of 555 connected to source side of that "shunt" so I can see
power draw of both at same time.

This is not a good situation. Now the 555 not only has choked input power from that silly "power limiting resistor", but it now has been "enhanced" with a noisy reference point to boot. This is modulating the entire 555 circuit with the voltage wave form on the 0.25 Ohm Source shunt. You were far better off using the separate 0.25 Ohm shunt for the 555, and tying it directly to the battery negative as before.

.99

[Harvey]

Lighty - I tried to read your link. Is there any chance of getting a translation here? I'm sure there are a number of us who'd be interested.

Lightly Site - Translated

[poynt99]

lighty,

LOL. You won't get any argument from me regarding the points you just made about theory and good design etc.

The point I was making is that this particular application goes against many facets of good design, but the goal is to achieve a certain effect, not stellar engineering design. Clearly using a lowly 555 chip to drive a slow MOSFET is not the epitome of good switching design.

Anyway, your points are well taken by a few, but again may I stress that many have already been proposed and hashed out among the troops. We're way beyond that point now. At this time it's all about proving the claims, and trying to attain an ever-elusive aperiodic mode of oscillation.

Happy trails.

.99

[lighty]

The math is clear and engineering rules are very well known. In fact I was engineering some very similar circuits for quite some time now and I think I have a pretty good grasp of what's going on in various parts of circuit. If you use such inadequate components they will cause unnecessary power losses and you can't beat that no matter what you try. Sorry, it's the fact.

Anyway, I'm currently buried under a ton of paperwork for a commercial project so I doubt I will be going through 132 pages of discussion. However you're right I should leave you people alone figuring out things for yourself. In fact it's perhaps better that you learn on your own mistakes than having someone pointing them out for you.

Off I go.

[poynt99]

lighty,

I think the problem here is that you're coming in quite late and out of the loop. Most of these issues have already been suggested and discussed etc. All good suggestions, but this is not the goal!

The IRFPG50 is THE MOSFET being used in this experiment. The goal is not fast switching etc. This is much different than conventional circuit design regarding this particular circuit, and in fact there are several things you are apparently not aware of regarding this whole topic. I suggest you do some reading and catch up if you don't want to be repeating the discussion here again.

.99

[Aaron]

schematic

Actually, this is the most accurate schematic I'm using. The only difference at the moment is different cap values on the timer circuit.

EDIT - actually, I'm not using 2 separate "shunts" for power measurements.
I have neg of 555 connected to source side of that "shunt" so I can see
power draw of both at same time.

[FuzzyTomCat]

@FuzzyTomCat and ALL

The 10 ohm resistor comprises a 10 ohm hollow core wire wound ceramic structure with a length of 150 mm (5.9055 in long). and a diameter of 32 mm ( 100.5308 mm / 3.9579 in circumference ). 48 turns of resistance wire (4825.4784 mm / 189.9795 in / 15.8316 ft long) are spaced at 1 mm. It was chosen for its inductance (8.64 micro Henries).

48 turns - 10 ohms @ 15.8316 feet = .63165 ohms ft
AWG 20 [.032 dia] ( .6348 ohms ft ) = ( 10.0499 ohms ) "Ni Cr A" 80% nickel, 20% chromium


So I gather from this that getting 10 ohms AND 8.64 micro Henries is what's important in reproducing this resistor to maintain the circuits performance?

Thank you,

@ dllabarre,

I'm sure you get results with the MEMCOR 10 ohm 100 watt "Load" resistor, but it's around 20 to 22 uH ..... it is the belief that the correct "micro Henries" will produce better inductive results and it's the correct size for a true ( + - ) replication

Glen

[Aaron]

schematic

Lighty, this is the schematic I'm using:

The values on the timer circuit may be different and I have a pot
between the battery and the timer circuit positive to vary how much
power I want it to have. And I have the timer powered by the same
battery as the load.

The 10 ohm resistor on the left side of the circuit is an inductive
resistor.