Hi,
I have read from a few places that the open area of ESL stator should be around 20-40% also the hole size should not be more than 4 mm. What if I were to use a lot more open area stator, what downsides can they be?
I'm now making a pair of ESL using 6 mm hexagon holes on 1 mm perforated metal sheet. Honestly, they actually sound wonderful. The only thing bad I can see is that 1 mm in thickness is rather floppy.
Visually, they look wonderful, too.
Wachara C.
I have read from a few places that the open area of ESL stator should be around 20-40% also the hole size should not be more than 4 mm. What if I were to use a lot more open area stator, what downsides can they be?
I'm now making a pair of ESL using 6 mm hexagon holes on 1 mm perforated metal sheet. Honestly, they actually sound wonderful. The only thing bad I can see is that 1 mm in thickness is rather floppy.
Visually, they look wonderful, too.
Wachara C.
The hole size can be usefully compared to the stator-diaphragm distance. If the holes are small compared to the stator-diaphragm distance then the electric field is less likely to vary significantly from one point on the diaphragm to another. If the holes are large compared to that distance, some areas of the diaphragm (those near the holes) may be driven with less force. You'll likely lose a bit of SPL, and it seems to me (without evidence to back it up) that you risk introducing some non-uniform diaphragm motions.
Few
Few
Hi JarreYuri,
Do you mean that you have tried touching the treble stator of Quad when you are playing music? That must have been very scary.
Frankly, I've been thinking whether I should put a protective cover for the ESL. I intend to put the ESL in my living room, and who knows maybe someone would like to touch it when the music is playing - especially those who don't know what ESL is.
Wachara C.
Do you mean that you have tried touching the treble stator of Quad when you are playing music? That must have been very scary.
Frankly, I've been thinking whether I should put a protective cover for the ESL. I intend to put the ESL in my living room, and who knows maybe someone would like to touch it when the music is playing - especially those who don't know what ESL is.
Wachara C.
Hi,
the risc of shock or flashover depends on:
- the shape of the conductor
- the thickness of the insulating material layer
- electrical properties of the insulating material
- quality of the insulative coating (e.g homogenity)
- duration of signal stress
- age of DUT
and maybe some more.
Openness of the stator probabely doesn´t play a role, at least not a major one.
jauu
Calvin
the risc of shock or flashover depends on:
- the shape of the conductor
- the thickness of the insulating material layer
- electrical properties of the insulating material
- quality of the insulative coating (e.g homogenity)
- duration of signal stress
- age of DUT
and maybe some more.
Openness of the stator probabely doesn´t play a role, at least not a major one.
jauu
Calvin
Hi Calvin,
Have you tried put your hand on your stator?
What do you think of 3 layers of powder coating? Do you think they are sufficient for good insulation?
What if I want to measure the electrical leakage on the stator. What is the simplest instrument that I can use to check? I have tried the screw driver that has a light bulb on it. If it shows no light, would it mean OK?
Wachara C.
Have you tried put your hand on your stator?
What do you think of 3 layers of powder coating? Do you think they are sufficient for good insulation?
What if I want to measure the electrical leakage on the stator. What is the simplest instrument that I can use to check? I have tried the screw driver that has a light bulb on it. If it shows no light, would it mean OK?
Wachara C.
Hi,
no panel leaves my house untested personally...which means touching both stators with both hands under full power (I don´t recommend to do that at all...no! no!), Well, I guess this means that either the insulation is ok, or I am freaky Frankenstein Junior
Instead You could try the leakage indicator (blinker circuit) with a piece of aluminium foil as large electrode.
3 layers of powder coat? Man, the coater that achieves a perfect coating with 3 layers must be really good More than two layers is very difficult because the new powder layer must completely melt while the old layer mustn´t start flowing. If the powder doesn´t melt completely, there will be unmolten particles along thats borders flashovers develop (the structure looks similar to Styropor). Even if the surface loks perfectly well the powder might not been molten in fullness and flashover treshold is much lower than it should be for a layer of such thickness. The 3rd (or even more) layers is better done wet, i.e. sprayed on with a clear PU-laquer. There should be a descrition of that technique in an earlier thread here.
jauu
Calvin
no panel leaves my house untested personally...which means touching both stators with both hands under full power (I don´t recommend to do that at all...no! no!), Well, I guess this means that either the insulation is ok, or I am freaky Frankenstein Junior
Instead You could try the leakage indicator (blinker circuit) with a piece of aluminium foil as large electrode.
3 layers of powder coat? Man, the coater that achieves a perfect coating with 3 layers must be really good
More than two layers is very difficult because the new powder layer must completely melt while the old layer mustn´t start flowing. If the powder doesn´t melt completely, there will be unmolten particles along thats borders flashovers develop (the structure looks similar to Styropor). Even if the surface loks perfectly well the powder might not been molten in fullness and flashover treshold is much lower than it should be for a layer of such thickness. The 3rd (or even more) layers is better done wet, i.e. sprayed on with a clear PU-laquer. There should be a descrition of that technique in an earlier thread here.jauu
Calvin
Noooooo 2
don´t you do that!
Of course I had the insulation tested extensively before, so I was sure about the capabilities of the insulation and that it was safe.
When I parachuted in earlier times I always took a parachute and a reserve with me, you know? And when I crashed into the guard rail with my motorbike I wore helmet and safety clothing.
I wouldn´t touch anything on a ESL which I don´t know exactly how it behaves.
jauu
Calvin
ps. the dustcover does just that: cover and prevent dust from getting into the stators. Since it must be very thin film the insulative property is rather low, maybe around 200-300V.
don´t you do that!
Of course I had the insulation tested extensively before, so I was sure about the capabilities of the insulation and that it was safe.
When I parachuted in earlier times I always took a parachute and a reserve with me, you know? And when I crashed into the guard rail with my motorbike I wore helmet and safety clothing.
I wouldn´t touch anything on a ESL which I don´t know exactly how it behaves.
jauu
Calvin
ps. the dustcover does just that: cover and prevent dust from getting into the stators. Since it must be very thin film the insulative property is rather low, maybe around 200-300V.
@calvin
Of course I know you know what you are doing. Everybody knows what safety measures to take with parachute diving or driving a bike, because we get proper training. Not so with the ESL hobbyist. My comment was directed at that poor stranger who walks in on this forum one day and might be tempted to try this, then dies a horrible death. This is a public forum and we should be careful what we write.
@Wachara
Depends on what you want to achieve. For the Quad ESL it is absolutely mandatory. For your home made ESL it does not provide much of an insulation but it might keep curious fingers out. The downside is that you can get dust cover resonances.
Of course I know you know what you are doing. Everybody knows what safety measures to take with parachute diving or driving a bike, because we get proper training. Not so with the ESL hobbyist. My comment was directed at that poor stranger who walks in on this forum one day and might be tempted to try this, then dies a horrible death. This is a public forum and we should be careful what we write.
@Wachara
Depends on what you want to achieve. For the Quad ESL it is absolutely mandatory. For your home made ESL it does not provide much of an insulation but it might keep curious fingers out. The downside is that you can get dust cover resonances.
Well, for starters, anyone who are even close to being serious about building en electrostatic loudspeaker has most sertainly come across the knowledge about "A" and "V". Ampere and Voltage.
Knowing this the person also know that the audio transformer is used to transform high amps to high voltage.
Also the person PROBABLY knows that the amplifier has a VOLUME-knob on it.
Low volume = low voltage on the secondary winding on the transformer. So on the stators.
The really dangerous thing is if there would have been 0,5 ampere or so. Then You would brobably caramp upp.
But this is not the case.
At low volumes You will feel a great tingeling sensation in beat with the musik. And this with NO insulation.
WITH insulation and a naked stator (as with Martin logan) You will hardly feel anything and in high volumes You will sense a bit of tingeling and NO DEATH!!!!!!! PERIOD.
One thing that can be dangerous is to short circuit the high voltage supply with Your hands.
That has a static charge.
NEVER EVER TOUCH THIS!!!
I know, I have been there! I got too close once and got the high voltage supply to travel from hand to hand through my body.
That was an experience I don't want anyone to feel.
Every muscle tensed up in a micro second and I was a bit out of breath afterwards.
One thing about information is that, given that this is an open forum, You should give all of the information. Not just a censored one. THAT is dangerous.
And just the idea to censore is like not selling kitchen knifes in the store in the case some dumb *** tries to cut his/her throught.
Everyone is responsible for their own actions!
Knowing this the person also know that the audio transformer is used to transform high amps to high voltage.
Also the person PROBABLY knows that the amplifier has a VOLUME-knob on it.
Low volume = low voltage on the secondary winding on the transformer. So on the stators.
The really dangerous thing is if there would have been 0,5 ampere or so. Then You would brobably caramp upp.
But this is not the case.
At low volumes You will feel a great tingeling sensation in beat with the musik. And this with NO insulation.
WITH insulation and a naked stator (as with Martin logan) You will hardly feel anything and in high volumes You will sense a bit of tingeling and NO DEATH!!!!!!! PERIOD.
One thing that can be dangerous is to short circuit the high voltage supply with Your hands.
That has a static charge.
NEVER EVER TOUCH THIS!!!
I know, I have been there! I got too close once and got the high voltage supply to travel from hand to hand through my body.
That was an experience I don't want anyone to feel.
Every muscle tensed up in a micro second and I was a bit out of breath afterwards.
One thing about information is that, given that this is an open forum, You should give all of the information. Not just a censored one. THAT is dangerous.
And just the idea to censore is like not selling kitchen knifes in the store in the case some dumb *** tries to cut his/her throught.
Everyone is responsible for their own actions!
Hi,
well Yuri, Yes and No! Yes, everybody is responsible for himself. No, because I can´t imagine anyone possibly likes the feeling of ´responsibity for an accident´.
Besides when I see some very weird verdicts especially of american lawsuits (with several millions of $ worth as punishment), I don´t want to get involved in such one.
So I don´t say that touching a decent designed HV-Bias is less dangerous than touching stators (which means very low wattage supply, small capacitance values and high ohmic resistors) ;-). But I do say that touching stators is risky because in case of a flashover or direct shock, there are not only high voltages involved but high current values too!
Anyway: Live long and prosper *gg*
jauu
Calvin
well Yuri, Yes and No! Yes, everybody is responsible for himself. No, because I can´t imagine anyone possibly likes the feeling of ´responsibity for an accident´.
Besides when I see some very weird verdicts especially of american lawsuits (with several millions of $ worth as punishment), I don´t want to get involved in such one.
So I don´t say that touching a decent designed HV-Bias is less dangerous than touching stators (which means very low wattage supply, small capacitance values and high ohmic resistors) ;-). But I do say that touching stators is risky because in case of a flashover or direct shock, there are not only high voltages involved but high current values too!
Anyway: Live long and prosper *gg*
jauu
Calvin
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