Could you share 833A and 3-500Z Circuits,is it possible ? We decided to do that amplifiers but we cant find anywhere this circuit.Please could you help us about that ?
My best regards
My best regards
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Nothing to it.
All you need is a proper output transformer.
Also do a search here, there are discussions of these tubes, and other similar tubes.
It's just another tube, nothing particularly special other than the high high voltage which makes for a very high impedance to match to, special sockets and the requirement of air cooling. You'd also need a proper amount of swing in the driver circuit. Other than that, nothing particularly special to be done.
I would advise against working with tubes that use this sort of high voltage if you need to ask to see a schematic to make one. They are DEADLY DANGEROUS not something that anyone without extensive experience should play with. One mistake and you are instantly DEAD.
_-_-bear
All you need is a proper output transformer.
Also do a search here, there are discussions of these tubes, and other similar tubes.
It's just another tube, nothing particularly special other than the high high voltage which makes for a very high impedance to match to, special sockets and the requirement of air cooling. You'd also need a proper amount of swing in the driver circuit. Other than that, nothing particularly special to be done.
I would advise against working with tubes that use this sort of high voltage if you need to ask to see a schematic to make one. They are DEADLY DANGEROUS not something that anyone without extensive experience should play with. One mistake and you are instantly DEAD.
_-_-bear
deadly high voltage is so correct.
A recent thread on a board where people are experienced with those kinds of voltages, and often do not need schematics, shows a graphic example of what happens to a hand when a connector was bad and no one knew about it.
Hit with 6kv yesterday... DON'T trust the Millen connectors!
Scoffers should read that, but they never do read such accounts, then one day we see any more posts from them.
Thought experiments are safe enough though. Something I have been wanting to try for a long time is a subwoofer amp using 3-500Zs. There is probably little advantage to using a tube amp over solid state in that application, the only one I can think of would be the generally softer clipping.
I have some Ling TP850 solid state 'vibration table' amplifiers rated about 930W for use as sub amps, but why not think about some tubes instead.
I have seen old frequency changers using tubes. Their output transformers are designed for limited range and so their defects are not exposed as they would be over the full audio spectrum. Some of them for changing 60 to 50Hz I would swear are nothing more than power transformers.
This leads me to think that it may be more practical to try a 3-500Z sub amp than a hi-fi amp where transformer cost is concerned.
I suggest that an old 60Hz 3KVA 'pole transformer' of the type having two 2400V HV windings and two 120V windings would be useful. I also suggest that two of them could be used by connecting the primaries in series in such a way that each is seviced by both tubes, and then making the appropriate secondary connections to match the low impedance load. The reason for using two of these 3KVA transformers is so that the full power of the tubes, about 1500W, can be passed at 30Hz. The low frequency power rule for transformers is that they can deliver half the power at 0.707 * the rated frequency and 1/4 the rated power at half the frequency. Therefore a 6KVA setup for 60Hz should handle 1.5KVA at 30Hz.
The size of 'pole pig' units on hand here may not be comon any more seeing the distribution is now usually 7-14KV, but it is possible to get a 3 phase 2400V (or whatever) unit and restack it using two windings for single phase use.
What a house of cards!
Will the blower for the 3-500Zs knock it down?
A recent thread on a board where people are experienced with those kinds of voltages, and often do not need schematics, shows a graphic example of what happens to a hand when a connector was bad and no one knew about it.
Hit with 6kv yesterday... DON'T trust the Millen connectors!
Scoffers should read that, but they never do read such accounts, then one day we see any more posts from them.
Thought experiments are safe enough though. Something I have been wanting to try for a long time is a subwoofer amp using 3-500Zs. There is probably little advantage to using a tube amp over solid state in that application, the only one I can think of would be the generally softer clipping.
I have some Ling TP850 solid state 'vibration table' amplifiers rated about 930W for use as sub amps, but why not think about some tubes instead.
I have seen old frequency changers using tubes. Their output transformers are designed for limited range and so their defects are not exposed as they would be over the full audio spectrum. Some of them for changing 60 to 50Hz I would swear are nothing more than power transformers.
This leads me to think that it may be more practical to try a 3-500Z sub amp than a hi-fi amp where transformer cost is concerned.
I suggest that an old 60Hz 3KVA 'pole transformer' of the type having two 2400V HV windings and two 120V windings would be useful. I also suggest that two of them could be used by connecting the primaries in series in such a way that each is seviced by both tubes, and then making the appropriate secondary connections to match the low impedance load. The reason for using two of these 3KVA transformers is so that the full power of the tubes, about 1500W, can be passed at 30Hz. The low frequency power rule for transformers is that they can deliver half the power at 0.707 * the rated frequency and 1/4 the rated power at half the frequency. Therefore a 6KVA setup for 60Hz should handle 1.5KVA at 30Hz.
The size of 'pole pig' units on hand here may not be comon any more seeing the distribution is now usually 7-14KV, but it is possible to get a 3 phase 2400V (or whatever) unit and restack it using two windings for single phase use.
What a house of cards!
Will the blower for the 3-500Zs knock it down?
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There have been multiple times I have advised people working on high voltage circuits.
One scenario is called: The surviving spouse syndrome.
When a corporation does not pay good enough attention, the surviving spouse
hires a high power lawyer, and the spouse and lawyer now own the company.
One scenario is called: The surviving spouse syndrome.
When a corporation does not pay good enough attention, the surviving spouse
hires a high power lawyer, and the spouse and lawyer now own the company.
A company I worked for, repaired old, charred, worn-out and obsolete mains-operated switching power supplies up to about 3-4KVA, high and low voltage. The company was unconcerned about many human factors and could easily get pwned if not destroyed by the above scenario.
They had this business because there are many 20-50 year old, million-dollar tools/high tech machines out there that must stay in operation even though many of the subcomponents are no longer supplied. Form factors are critical and exact replacements not available. The customers don't care what it costs to get that supply fixed because production line-down costs them more.
How to list the factors without pinpointing a very negligent firm.. I won't name them.
1. Steel workbenches grounded and supplied with isolation transformer for oscilloscope only. That is to say it is cheaper to isolate the scope with a 100VA transformer and protect a 35 year old scope, than to isolate the mains-connected 400V PFC front end power supply operating opened-up on the bench with a 3KVA isolation transformer and protect the employee.
2. In the power supply test/burn-in room there were two workbenches side by side. One was for low voltage suplies and one for high voltage stuff up to 30-40KV and over 100mA. There was no warning lamp to keep employees aware/reminded when the HV was ON from their clip-lead hookup. One hand made sign in black and white (no red, amateurs) gave warning right at the HV bench.
The HV load resistor bank was inches from the right edge of the very actively used low voltage power supply test bench with only a small plexiglass panel and open box-like affair separating the home made 30KV load bank from the employee.
There was a rack with 1 & 3KVA low voltage high current DC loads to the right-rear of the employee to be used with the LV test bench, but to access the connections, the employee had to reach or get behind this rack since the cables were big like 00 and larger gauge welding cables with bolted on lugs frequently rearranged.
To do this, the employee had to traverse a section of floor 3 FT wide between the HV load and LV rack, across which several of these fat cables and other smaller power and data cables were haphazardly strewn. The employee could trip and fall into the 30KV lash-up to die.
There was also no barrier or stanchioned-off arrangement preventing walk-up to the 30KV power supply burn-in bench from the front.
To access the fan, the employee had to cross right in front of the HV bench to reach a wall outlet. The fan is important because of the next thing.
3. Their idea of air conditioning for technicians work bench areas is 85 degrees F. It was more like 90-95 in the burn-in room. One wore a headband.
For this reason the employees were drenched in sweat. Their hands would be slippery on tools and so that conductivity to the employees' flesh was excellent.
4. Because of the HVAC expense avoidance and resulting sweatshop environment, employees were encouraged to avoid 'hot' protective clothing like long pants and work shoes and instead work in shorts and sneakers.
5. No protective eyewear was provided, so that when an attempt at a repair occasionally failed and the MOSFETs exploded, a serious projectile hazard existed.
During the time I was there I saw people get shocked, cut, and one get up and walk very quickly to the restroom with his hand on his face after a loud bang.
Those pale by comparison to the employee at the next bench over from me who somehow accidentally put his sweaty palm on the prickly solder side of the through-hole a PFC front end circuit board and burned a hole in it.
He showed this to me an hour later and it was swollen and red around an ugly charred spot and I told him to go to the ER or doctor right away. He refused, saying it was OK and he needed to finish up that job.
What possible reason could there be for this?
6. There was a quota system in place which was not easy to meet considering the 20-30 year old, obsolete, heat-burned, and undocumented power supples being repaired. The place published rates of $100-150 per hour and at the same time they gave a flat rate repair price for each model of unit, implying to the customer 4-8 hours of work to resurrect the old corpse.
This, in combination with the quota, required very hasty and unsafe work, but let them secretly charge around $400 an hour on each unit going by technician clock time, with the customer completely unaware that the repair was done in a fraction of the time implied. No comment on the ethics of that, but the co-worker with the severely burned hand was running so scared for his job that he put one lousy day of the employer's profit first, before and above the care of his own hand by which he made his living.
Pay was good but I didn't stay long in that miserable hellhole.
They had this business because there are many 20-50 year old, million-dollar tools/high tech machines out there that must stay in operation even though many of the subcomponents are no longer supplied. Form factors are critical and exact replacements not available. The customers don't care what it costs to get that supply fixed because production line-down costs them more.
How to list the factors without pinpointing a very negligent firm.. I won't name them.
1. Steel workbenches grounded and supplied with isolation transformer for oscilloscope only. That is to say it is cheaper to isolate the scope with a 100VA transformer and protect a 35 year old scope, than to isolate the mains-connected 400V PFC front end power supply operating opened-up on the bench with a 3KVA isolation transformer and protect the employee.
2. In the power supply test/burn-in room there were two workbenches side by side. One was for low voltage suplies and one for high voltage stuff up to 30-40KV and over 100mA. There was no warning lamp to keep employees aware/reminded when the HV was ON from their clip-lead hookup. One hand made sign in black and white (no red, amateurs) gave warning right at the HV bench.
The HV load resistor bank was inches from the right edge of the very actively used low voltage power supply test bench with only a small plexiglass panel and open box-like affair separating the home made 30KV load bank from the employee.
There was a rack with 1 & 3KVA low voltage high current DC loads to the right-rear of the employee to be used with the LV test bench, but to access the connections, the employee had to reach or get behind this rack since the cables were big like 00 and larger gauge welding cables with bolted on lugs frequently rearranged.
To do this, the employee had to traverse a section of floor 3 FT wide between the HV load and LV rack, across which several of these fat cables and other smaller power and data cables were haphazardly strewn. The employee could trip and fall into the 30KV lash-up to die.
There was also no barrier or stanchioned-off arrangement preventing walk-up to the 30KV power supply burn-in bench from the front.
To access the fan, the employee had to cross right in front of the HV bench to reach a wall outlet. The fan is important because of the next thing.
3. Their idea of air conditioning for technicians work bench areas is 85 degrees F. It was more like 90-95 in the burn-in room. One wore a headband.
For this reason the employees were drenched in sweat. Their hands would be slippery on tools and so that conductivity to the employees' flesh was excellent.
4. Because of the HVAC expense avoidance and resulting sweatshop environment, employees were encouraged to avoid 'hot' protective clothing like long pants and work shoes and instead work in shorts and sneakers.
5. No protective eyewear was provided, so that when an attempt at a repair occasionally failed and the MOSFETs exploded, a serious projectile hazard existed.
During the time I was there I saw people get shocked, cut, and one get up and walk very quickly to the restroom with his hand on his face after a loud bang.
Those pale by comparison to the employee at the next bench over from me who somehow accidentally put his sweaty palm on the prickly solder side of the through-hole a PFC front end circuit board and burned a hole in it.
He showed this to me an hour later and it was swollen and red around an ugly charred spot and I told him to go to the ER or doctor right away. He refused, saying it was OK and he needed to finish up that job.
What possible reason could there be for this?
6. There was a quota system in place which was not easy to meet considering the 20-30 year old, obsolete, heat-burned, and undocumented power supples being repaired. The place published rates of $100-150 per hour and at the same time they gave a flat rate repair price for each model of unit, implying to the customer 4-8 hours of work to resurrect the old corpse.
This, in combination with the quota, required very hasty and unsafe work, but let them secretly charge around $400 an hour on each unit going by technician clock time, with the customer completely unaware that the repair was done in a fraction of the time implied. No comment on the ethics of that, but the co-worker with the severely burned hand was running so scared for his job that he put one lousy day of the employer's profit first, before and above the care of his own hand by which he made his living.
Pay was good but I didn't stay long in that miserable hellhole.
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