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Re: Starting gas for a pretty good price. [collecting payments]
Ah. How would I go about safely discharging the tube?
Ah. How would I go about safely discharging the tube?
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[CLOSED] Starting gas for a pretty good price
- Thread starter ultimatekaiser
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Re: Starting gas for a pretty good price. [collecting payments]
If youre using a commercial supply brick, they usually bleed down over the course of a few minutes. Most of the ones I have do. The tube especially when connected to the supply acts like a capacitor. If you need discharge it in a hurry you can string a few (well insulated) 100K resistors together and use them to bridge the tube anode and cathode to drain the tube and PSU cap bank slowly. I wouldn't recommend doing a fast short, as it stresses the power supply and can damage it.
If youre using a commercial supply brick, they usually bleed down over the course of a few minutes. Most of the ones I have do. The tube especially when connected to the supply acts like a capacitor. If you need discharge it in a hurry you can string a few (well insulated) 100K resistors together and use them to bridge the tube anode and cathode to drain the tube and PSU cap bank slowly. I wouldn't recommend doing a fast short, as it stresses the power supply and can damage it.
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Re: Starting gas for a pretty good price. [collecting payments]
Speaking of which I'm suprised at who we are waiting on...they were the ones I thought would end up paying much faster
Oh blooooom... -pokes dorm door with a HeNe tube-
Speaking of which I'm suprised at who we are waiting on...they were the ones I thought would end up paying much faster
Oh blooooom... -pokes dorm door with a HeNe tube-
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Re: Starting gas for a pretty good price. [collecting payments]
Really? I would think if you shorted the tube by attaching a clip lead to the cathode and clipping the other end to an insulated screw driver one could simply short the anode of the tube to discharge it without causing any damage. Now, the PSU maybe a different story, but I really don't see why.
Really? I would think if you shorted the tube by attaching a clip lead to the cathode and clipping the other end to an insulated screw driver one could simply short the anode of the tube to discharge it without causing any damage. Now, the PSU maybe a different story, but I really don't see why.
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Re: Starting gas for a pretty good price. [collecting payments]
No it won't hurt the tube. The tube could care less...in fact, many of my tubes that are larger, I just unplug the Alden and tap the cathode pin on the anode mirror mount. But as these tiny tubes don't have an Alden, you would be shorting it while still attached to the power supply before touching the anode end. You technically could short it with a screwdriver something if you wanted, it's just hard on the power supply to force discharge it all at once.
No it won't hurt the tube. The tube could care less...in fact, many of my tubes that are larger, I just unplug the Alden and tap the cathode pin on the anode mirror mount. But as these tiny tubes don't have an Alden, you would be shorting it while still attached to the power supply before touching the anode end. You technically could short it with a screwdriver something if you wanted, it's just hard on the power supply to force discharge it all at once.
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Re: Starting gas for a pretty good price. [collecting payments]
I'm sorry, but I just don't see it. What part of the PSU is stressed by discharging it all at once? I've discharged similar circuit all my life and never had an issue with it. I must be missing something, I don't see what is distressed?
I'm sorry, but I just don't see it. What part of the PSU is stressed by discharging it all at once? I've discharged similar circuit all my life and never had an issue with it. I must be missing something, I don't see what is distressed?
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Re: Starting gas for a pretty good price. [collecting payments]
A lot of people discharge caps that way, even big ones. As my teacher has always said..."just because everyone does it, it doesn't make it the right way"
Discharging the starting caps the hard way shortens their lifespan, and you should always bleed them slowly. I know a lot of technicians preach otherwise, but it is true. I did that with the high-voltage cap array once, I literally vaporized the end of the screwdriver and it scorched the cap terminals. And It's hard on the caps' internal parts, making them leak faster.
(Though this is extreme for this, but it's just a bad habit I guess is what I wanna say)
A lot of people discharge caps that way, even big ones. As my teacher has always said..."just because everyone does it, it doesn't make it the right way"
Discharging the starting caps the hard way shortens their lifespan, and you should always bleed them slowly. I know a lot of technicians preach otherwise, but it is true. I did that with the high-voltage cap array once, I literally vaporized the end of the screwdriver and it scorched the cap terminals. And It's hard on the caps' internal parts, making them leak faster.
(Though this is extreme for this, but it's just a bad habit I guess is what I wanna say)
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Re: Starting gas for a pretty good price. [collecting payments]
Don't take this the wrong way. I never said to discharge banks of high current capacitors by shorting them out. I have never done that. But, the ceramic high voltage disc capacitors are two plates separated by a high voltage dielectric and they can take the discharge just fine as they must in the circuits that some of them occupy if the flyback interval is short enough in duration. But, high capacity banks of electrolytic capacitors or other similar banks of caps would surely cause damage if discharged that way.
Don't take this the wrong way. I never said to discharge banks of high current capacitors by shorting them out. I have never done that. But, the ceramic high voltage disc capacitors are two plates separated by a high voltage dielectric and they can take the discharge just fine as they must in the circuits that some of them occupy if the flyback interval is short enough in duration. But, high capacity banks of electrolytic capacitors or other similar banks of caps would surely cause damage if discharged that way.
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Re: Starting gas for a pretty good price. [collecting payments]
This is true, but I've always been taught to just do both for safety reasons. But you are right. I just want to set a good example, as it's still good practice.
This is true, but I've always been taught to just do both for safety reasons. But you are right. I just want to set a good example, as it's still good practice.
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Re: Starting gas for a pretty good price. [collecting payments]
Two tips for handling tubes that haven't had time to bleed off:
1. Keep a good pair of gloves around. I have a cheap pair of winter gloves I picked up for a couple bucks at the hardware store that work nicely. Leather palmed work gloves should be fine as well. Something like these
Shop Blue Hawk Large Men's Leather Palm Work Gloves at Lowes.com
should do the trick. Just make sure whatever gloves you use don't have a loose weave or holes in them that can allow a path to ground.
2. If the tube is connected to the PSU with an Alden style connector carefully unplug it (sometimes I've had to gently pry them apart as they can get stuck) avoiding the pins on the end of the cable from the tube. Using an insulated screw driver short the pins. Depending on the charge on the tube you may see, or hear, a spark jump as it discharges. I usually short them a couple times to make sure the charge is gone.
While it'll hurt like hell getting "bit" is harmless for 99.999% of people since the high resistance of your skin will stop the small amount of current from reaching your heart. There's always that one in a million chance something could happen but unless you have heart issues or a pacemaker I wouldn't be worried. The biggest risk IMO is dropping the tube. I've been bitten by my 594 tube and the finger that got zapped hurt for quite awhile afterwards but there was no lasting effect from it.
Two tips for handling tubes that haven't had time to bleed off:
1. Keep a good pair of gloves around. I have a cheap pair of winter gloves I picked up for a couple bucks at the hardware store that work nicely. Leather palmed work gloves should be fine as well. Something like these
Shop Blue Hawk Large Men's Leather Palm Work Gloves at Lowes.com
should do the trick. Just make sure whatever gloves you use don't have a loose weave or holes in them that can allow a path to ground.
2. If the tube is connected to the PSU with an Alden style connector carefully unplug it (sometimes I've had to gently pry them apart as they can get stuck) avoiding the pins on the end of the cable from the tube. Using an insulated screw driver short the pins. Depending on the charge on the tube you may see, or hear, a spark jump as it discharges. I usually short them a couple times to make sure the charge is gone.
While it'll hurt like hell getting "bit" is harmless for 99.999% of people since the high resistance of your skin will stop the small amount of current from reaching your heart. There's always that one in a million chance something could happen but unless you have heart issues or a pacemaker I wouldn't be worried. The biggest risk IMO is dropping the tube. I've been bitten by my 594 tube and the finger that got zapped hurt for quite awhile afterwards but there was no lasting effect from it.
Sigurthr
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Re: Starting gas for a pretty good price. [collecting payments]
Non-pulse-rated caps are internally compromised from dump-style discharges; it's well documented. The reason techs preach otherwise is for servicemen safety - not component lifetime.
I've been bitten by HeNes a whole lot (and many other things way more lethal), it's generally regarded as safe for someone in good health. It's best to never take a shock from one arm to the other (cross chest), but even so it's rare (but not impossible) to be seriously injured.
The biggest risk is dropping the tube! A cracked non-632 hurts a hell of a lot more than a bitten finger.
Non-pulse-rated caps are internally compromised from dump-style discharges; it's well documented. The reason techs preach otherwise is for servicemen safety - not component lifetime.
I've been bitten by HeNes a whole lot (and many other things way more lethal), it's generally regarded as safe for someone in good health. It's best to never take a shock from one arm to the other (cross chest), but even so it's rare (but not impossible) to be seriously injured.
The biggest risk is dropping the tube! A cracked non-632 hurts a hell of a lot more than a bitten finger.
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Re: Starting gas for a pretty good price. [collecting payments]
I think I'll just stick with not touching the tube for a little bit after its been run
Luckily I'm no stranger to high voltage shocks. (Is that lucky? I suppose I won't be as easily startled by it). I just recently managed to zap myself with one of those electric flyswatters. 1000 volts going through a finger is unpleasant.
I think I'll just stick with not touching the tube for a little bit after its been run
Luckily I'm no stranger to high voltage shocks. (Is that lucky? I suppose I won't be as easily startled by it). I just recently managed to zap myself with one of those electric flyswatters. 1000 volts going through a finger is unpleasant.
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Re: Starting gas for a pretty good price. [collecting payments]
Yep. Sig said it in summation great. And it does feel similar to that flyswatter I imagine.
These small tubes don't bite very hard, but the larger ones can be more dangerous.
Sam also has told me that the supplies can be damaged from such a dump, though unlikely...
Yep. Sig said it in summation great. And it does feel similar to that flyswatter I imagine.
These small tubes don't bite very hard, but the larger ones can be more dangerous.
Sam also has told me that the supplies can be damaged from such a dump, though unlikely...
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Re: Starting gas for a pretty good price. [collecting payments]
I just fried a HeNe Driver a couple weeks ago.
But it was from the feed side not the alden side.
I had to pay for another from Sam. That should teach me not to just touch wires instead of making a solid connection - Grumble, grumble, grumble….
I was told by Sam that it is difficult to hurt the tube doing these things, but the HeNe Driver is another story.
I just fried a HeNe Driver a couple weeks ago.
But it was from the feed side not the alden side.
I had to pay for another from Sam. That should teach me not to just touch wires instead of making a solid connection - Grumble, grumble, grumble….
I was told by Sam that it is difficult to hurt the tube doing these things, but the HeNe Driver is another story.
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Re: Starting gas for a pretty good price. [collecting payments]
Yeah the regulator and the LV side are not very durable at all. most laser supplies are made to barely cover what is needed. Much to my chagrin... Makes them blow up rather easy, so I tend to baby my stuff a lot.
Yeah the regulator and the LV side are not very durable at all.
most laser supplies are made to barely cover what is needed. Much to my chagrin... Makes them blow up rather easy, so I tend to baby my stuff a lot.
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Re: Starting gas for a pretty good price. [collecting payments]
I agree, the primary side of a high voltage circuit can be extremely unforgiving. It takes little to destroy the output transistors or other semiconductors in this part of the circuit. One should never go stomping around in this part of the PSU unless you are quite familiar with the circuit, or you may suffer the consequences. Also, when powered up, messing around in the secondary side of the PSU can cause damage to the primary part of the circuit as well.
I agree, the primary side of a high voltage circuit can be extremely unforgiving. It takes little to destroy the output transistors or other semiconductors in this part of the circuit. One should never go stomping around in this part of the PSU unless you are quite familiar with the circuit, or you may suffer the consequences. Also, when powered up, messing around in the secondary side of the PSU can cause damage to the primary part of the circuit as well.
