Scubasteve2365 said:
I know some baseboard heating systems run off 240V. In the US typically electrical panels are supplied with at least two opposing phase hot 120V lines. To wire 240 you just wire a breaker across these two hot lines. I have a 240V outlet here in my basement for a welder (that is long gone).
TaskMaster said:
Yeah, I know for high power situation we have things like that here in the states ..... there are 3phase systems in either Y or delta configurations that alot of manufcaturing facilites use to drive their equipement (belt motors and such)
but I was unaware of that being a standard, in every house plug your your hair dryer into the wall system ....
Yep, this is the reason why electricians usually install the breakers in a balanced number between the left and right columns in a breaker box, e.g for six breakers it would be two colums of three instead of one column of six. This balances the load between the different phases wired to the box (typically one phase supplies each column).
Scubasteve2365 said:
Well Scuba,
Whatever you paid for that sterling education, you clearly didn't pay enough.
You say an INCREDIBLE amount without actually answering the question.
In fact, you say just enough to indicate that you got the facts COMPLETELY wrong.
That aside, I am VERY impressed with your algebra...
Hertz: Thanks for your help. I am happy to risk a ballast collapsing within a matter of days.
Scubasteve2365,
Sorry if i sound offending in my reply but i don't meant it that way.
Thank you for reminding me how to get the power factor mathematically.. Its just that i thought we need to test it in a real world with a meter to get the realistic result. We will need given data in order to come up with our computation.
All i want to say to goemon run the ballast under correct operating condition to get the best result. Running the ballast undervoltage will give you bad result.
Its true that the lamp will draw more current from the ballast but the lamp brightness will suffer.
I have a variable power supply and i had an idea already how bright my lamp will be at different voltage and current supplied to the ballast and the lamp. A wattmeter could help us out better in determining power (watts) consumed by the lamp. ( 250 watts Hqi-tsd is rated to run at 100v at 3amp.)
BTW, I have 3 Hqi-bulbs and you will be surprised that each operate at different voltage using the same ballast. The one that operates at higher voltage is brighter than the others. The one that operates at higher current at lower voltage is dimmer. At least base on my subjective experiment..
I've been reading the tutorial from Advance transformer about how to get the best from HID ballast and i guess being an electrical engineer like us has an edge to easily grasp the knowledge and can easily share and explain it to the others the simplest way possible.
Regards,
Hert
Sorry if i sound offending in my reply but i don't meant it that way.
Thank you for reminding me how to get the power factor mathematically.. Its just that i thought we need to test it in a real world with a meter to get the realistic result. We will need given data in order to come up with our computation.
All i want to say to goemon run the ballast under correct operating condition to get the best result. Running the ballast undervoltage will give you bad result.
Its true that the lamp will draw more current from the ballast but the lamp brightness will suffer.
I have a variable power supply and i had an idea already how bright my lamp will be at different voltage and current supplied to the ballast and the lamp. A wattmeter could help us out better in determining power (watts) consumed by the lamp. ( 250 watts Hqi-tsd is rated to run at 100v at 3amp.)
BTW, I have 3 Hqi-bulbs and you will be surprised that each operate at different voltage using the same ballast. The one that operates at higher voltage is brighter than the others. The one that operates at higher current at lower voltage is dimmer. At least base on my subjective experiment..
I've been reading the tutorial from Advance transformer about how to get the best from HID ballast and i guess being an electrical engineer like us has an edge to easily grasp the knowledge and can easily share and explain it to the others the simplest way possible.
Regards,
Hert
Here is what i thought it will be . Please correct me if i'm wrong.
The high current will cause the ballast to heat up, not the power it delivers to the lamp.
example using the same ballast
Ist condition : 100 volts x 2 amp = 200va
2nd condition ; 50 volts x 4 amp = 200va
Condition 2 will run hotter because of bigger power consumed by the ballast. Ballast temperature will be different under this 2 operating condition.
hertzblaster said:
Yeah, I think the same thing ..... the higher current will theoretically yeild more heat transfer ... especially since voltage is just "current potential" anyway ..... but .... most of any heat that you can feel is often power ... especially coming from an electronic device that has heat sinks and what not ..... I honestly believe that both temps above will be very very close in temperature .... If I had to pick one that would run hotter it would be the 2nd condition No doubt .... but since they are both dissipating the same amount of power then they SHOULd be very close in temperature.
That is assuming that in both conditions the circutis are stable... If the 2nd condition is TOO much current for the circuit, as to where all the internal devices are running hot, and reaching their threshold ... then the 2nd condition will run alot hotter ... but not for long, before something releases the magic smoke .... and it no longer works ....
I also think alot of this will matter depending on if your using an electronic ballast, or an old coil ballast. Im using a coil ballast, and the thing spits out a consistant 275V-300V with an open load (No Bulb) ... I havnt really measured with the bulb in ... but im certain that different bulbs will draw different brightness (even if they are supposed to be the same)
Goemon1966 said:
Well Scuba,
Whatever you paid for that sterling education, you clearly didn't pay enough.
You say an INCREDIBLE amount without actually answering the question.
In fact, you say just enough to indicate that you got the facts COMPLETELY wrong.
That aside, I am VERY impressed with your algebra...
Hertz: Thanks for your help. I am happy to risk a ballast collapsing within a matter of days.
i did answer the question ... sorry if I didnt put it into a simple matter of sure plug it in, or dont plug it in .... Sometimes things arent that simple ......
but Im curious to know what FACTS, I have wrong .... better yet completly wrong?? Please Educate me where my Professors have failed to do so ..... LOL ...
Please enlighten me on this. I maybe be wrong.
example using the same ballast
Ist condition : 100 volts x 2 amp = 200va
2nd condition ; 50 volts x 4 amp = 200va
To clarify, The volts is represented as voltage across the lamp not the voltage across the ballast.
The 2nd condition will run much hotter. Power dissipation under this 2 conditions are very much different. (P=I^2 *R) P is power loss in the ballast. The above conditions are using the same ballast so R is constant.
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hertzblaster said:
If it has a over heating temperature cut-off similar to that of a car amplifier, it could help ...... but, if still running in too much of an unstable condition it will eventually give up and die .....
When i worked for the stereo shop, we were often told to try and blow stuff up by the manufacturers .... .... Alot of decent amps were thermal protected, but that did nothing when I gave it a 1-ohm load.
hertzblaster said:
It would be too hard to say .... I does change the game when saying that its the voltage across the bulb and not the ballast. Cause in that situation we dont have any clue what power the ballast is dissapating.
and since we dont know what the ballast is made of exactly, we dont exactly know how much current is running through it. Sures its outputting 4amps .... but in both conditions alot more current could be running through it, or not .... we simply dont know.
Also since, the 2nd condition is outputting less voltage, then that must mean that the ballast is dropping more voltage in the second condition than in the first .... which could potentially mean that the current may be doubled by a factor of two, but the voltage reduced by a factor of two and then vice versa..... yeilding, yet the same power dissapation.
Lets clarify it more for the benefit of those who find this discussion interesting..
example using the same ballast
Ist condition : 100 volts x 2 amp = 200va
2nd condition ; 50 volts x 4 amp = 200va
To clarify, The volts is represented as voltage across the lamp not the voltage across the ballast.
Our assumption here is we are running the ballast with correct input voltage in the first condition and low input volatge in the second condition
Another assumption is that we are using a simple reactor electromagnetic ballast ( ballast is connected in series with the lamp)which i believe is most popularly used in our project.
We can tell how much is the voltage drop across the ballast by using a simple multimeter
So the power loss in the ballst is given by
P = voltage drop across the ballast x current
The higher the power loss ( power consumed by the ballast), the hotter the ballast will be.
This maybe a little off topic , but its about heat so its related..
I diy my own subwoofer amplifier and also built the speaker protector for it. Maybe i was just lucky, but i never blow up my power transistor .
In my case, Power transistor is not protected thermally thru the use of heat sensor (like the thermal protection for pc processor) but by monitoring the current delivered to the speaker. SO when the impedance say is 1 ohm, the more current will be delivered to the speaker so that power will be cut-off base on the pre-set. Higher current will heat up the power transistor.
I had also spend some time to study the impedance curve of the speaker when the apllied frequency is varied. I was so surprised that at certain low frequency, the speaker impedance of the speaker can go as low as less than 1 ohm, if left uncontrolled will blow up the amp or the speaker windings because of overcurrent ( overheating). This is where the overcurrent protection ( speaker protector) will come in.
So in our diypj application, a simple overcurrent protection ( like fuse with time delay or a circuit breaker ) may help protect our ballast and our lamp.
An externally hosted image should be here but it was not working when we last tested it.
Its not electronically controlled, the ballast contact is opened by a certain material ( can't recall the material, maybe asphalt but i will check again)) that will expand when heated.
An externally hosted image should be here but it was not working when we last tested it.
A computer proccessor dont have thermal protection at all, its controlled via the motherboard. Not all mothboards have this feature so not all chips that are capable of being thermally shut off (when they reach the overheat threshold), the mobo has to suport it.
If your on about a fried chip, stick it in the freezer for 6 hrs and it will come back to life, atleast thats what used to work on the old k6-2 AMD chips, (i doubt on the new).
Trev
You got it accurately. Its the motherboard that monitors the processor temp not the processor itself. . i guess all new motherboard model has this control..
I didn't know before that you are also into pc building Trev, were you an overclocker (crazy me!) just like me before?
Thanks a lot to you . I can't find time now to do experiments. But because of your so many test and research that you share, it saves me a lot of time and money.
hertzblaster said:
LOL, yeah i wish there was more of me out there bud to save myself more time and money lol, though everyone at some stage does there bit, and it all helps, including the new guys and their problems.
Ive been into comp building for quite some time bud, since about 1997. I used to overclock but i find these days its not overly needed so i dont realy bother now. I like to modd stuff though, ive got a very compact htpc idea comming up, you wana be good with a soldering iron though.
Trev
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