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Author Topic: Another 813 Build  (Read 105726 times)
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w9jsw
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« Reply #100 on: July 07, 2019, 10:46:51 AM »

Hi Ed,

With option 2, I can probe all of the taps on the mod iron. Option 1, not so much, so perhaps I will go with option 2. The taps for the PS are on the front and top and can easily be accessed by removing a louver, or reaching in the back with the door open. The next item in the rack will be a PS chassis for the bias supplies. It will be a short chassis that still gives me space to safely probe. As to removing the transformers, they are easily removed with the sides off. I used t-nuts and bolts to hold them down. Easy nutdriver access to remove the bolts.

Given that this was the only rack I could find, have to make do. It would really be nice to have 6 more inches of space. It will still be easier than changing an alternator on one of our cars.

Thanks for the comments.

John
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« Reply #101 on: July 07, 2019, 06:27:32 PM »

Progress...

The meter is special. I don't recall where it came from. I have had it since I was a kid some 50 years ago, probably a ham-fest. I had it in a single meter enclosure and it has knocked around with me since college or before. I had set it up to be a 25V dc meter. I really needed to use this meter on this project...needs cleaning.

PS front panel laid out. No indicator lights as the Off-On SW lights up in the center. I need a power stat metal disc. Anyone have one laying around?

I think I finalized the iron footprint, baring any unforeseen obstacles that you guys point out. See anything odd or out of place?  Grin

John


* Special Meter.JPG (426.57 KB, 3264x2448 - viewed 412 times.)

* PS Front.JPG (474.83 KB, 3264x2448 - viewed 431 times.)

* Final Layout.JPG (564.15 KB, 3264x2448 - viewed 449 times.)
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« Reply #102 on: July 07, 2019, 06:38:26 PM »

Hi John,

Looks robust!   You are a trooper working into the hot summer when many take a building break.


Question: Maybe it's an optical illusion, but how much space is between the bare HV diode leads and the plate transformer iron?   Dust, moisture, sharp edges, corona, reactor collapsing fields, etc., can cause arcing greater than the normal 1/2" = 10KV standard.  I would have at least 1" of space there.  Or, a Plexiglas plate placed under the diode board would suffice.


T


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« Reply #103 on: July 07, 2019, 06:49:45 PM »

There is a Plexiglas plate there... Your browser may allow you to zoom in to see it.

You know, a lot of guys would like to have this problem. This is some serious kick a** iron that Phil sold me.  Cool

This is being built in my basement. So nice and cool down there. Kind of like building a yacht in the basement. Won't be my problem to get it out of there... My goal is to be doing trials in the fall/winter.

Has Yaz been taking you sailing this summer? Where do you usually go? Salt or fresh?

John
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« Reply #104 on: July 21, 2019, 04:42:21 PM »

PS build continues. No pics, just boring stuff. Relay wiring etc. I take my time. Solder connectors, then shrink wrap the ends to make them nice looking.

One thing though - installing the power cord. Bought a 30A 4 conductor dryer cord. This is when you embrace the fact that building one of these rigs is a whole new ballgame! Last time I messed with a cord like this was wiring an arc welder.   Shocked

John
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« Reply #105 on: July 22, 2019, 10:20:56 AM »

Hi Ed,

With option 2, I can probe all of the taps on the mod iron. Option 1, not so much, so perhaps I will go with option 2. The taps for the PS are on the front and top and can easily be accessed by removing a louver, or reaching in the back with the door open. The next item in the rack will be a PS chassis for the bias supplies. It will be a short chassis that still gives me space to safely probe. As to removing the transformers, they are easily removed with the sides off. I used t-nuts and bolts to hold them down. Easy nutdriver access to remove the bolts.

Given that this was the only rack I could find, have to make do. It would really be nice to have 6 more inches of space. It will still be easier than changing an alternator on one of our cars.

Thanks for the comments.

John

I would choose a layout with the oil capacitor terminals facing up in case of future leaks.

32uF vs 64uF will probably be almost unmeasurable if it's about ripple.

If the bias supply is on a smaller or narrow chassis then the caps can be mounted to a 2-3U piece of rack panel with straps, and the panel bolted horizontally to the inside of the side of the rack so the caps are vertical. I see some holes there. The power supply control panel looks like it gives plenty of room vertically if the bias suply is to be above it.

Long HV leads don't bother me except for abrasion and so I mounted some 1" PVC pipe to conduct them vertically between levels, so that the wires are not fastened against the metal. The PVC pipe is held to the rack side supports by pipe clamps top and bottom. A large one was easily bent to fit over both PVC pipes but I could have used one larger pipe save it had to fit into the exact space between 2 joined racks.

I think an 8" style variac dial scale is made for that size unit. Only a spare 4" here, too small for that!

Good on soldering your connectors. Crimping and assuming it will last forever is for the cheap seats! Nice on the double 3/4" floor.
Are you using plug-in relays or din mount or socketed panel mount? Just curious.

Have you decided on/collected panel meters for the usual parameters?
A couple rows of meters always looks great but space sometimes dictates some sharing like one meter for Modulator plate current 1/2/both, etc..

Do you plan a passive built-in 'test' multimeter to help highlight any future problem area or reduce the amount of probing or disassembly? I guess it's a luxury but it could reduce probing hot areas and save the back-ache.

Wonderful how this is coming along. Please post more pictures even of little things like relays and innovations/tricks.

 Smiley


* 100_2109.JPG (20.4 KB, 277x546 - viewed 407 times.)
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« Reply #106 on: July 22, 2019, 10:26:01 AM »

If you really wanted to be safe from a shorted frame, tie a resistor to the frame of the isolated xformer / choke and use ohms law to drop it to 120 volts (or 24, depending on the trip voltage) and hit a shunt trip breaker.

That will keep the breaker from staying live under any circumstance darn near.....  Even if you lost ground connection to the chassis somewhere/how.

This is how electric is cut during a fire or other event in commercial and industrial electric.

--Shane
KD6VXI

Been thinking about this a lot. It seems easier than it might appear and when a relay is activated, a lamp could indicate which one, assuming it could latch and had its own fused connection to the power input separate from the power supply contactor and breaker.
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« Reply #107 on: July 22, 2019, 04:26:06 PM »

How did you get that rectangular hole in the front panel for the power switch?
I have hand tools, it would be a lot of work for me to do it that way, filing and such.
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« Reply #108 on: July 23, 2019, 06:39:32 AM »

Agree with all of your suggestions. Will post more pics this weekend. The bias supplies are going just above the PS on a 17x10 chassis so there will be ample room behind. I have lots of meters to mount. Just wish it was easier to cut 2 3/4 in holes. Been using a saber saw. Panels are powder-coated steel. Aluminum is way too expensive.

The switch mounts in a round hole and is pretty unique. It has a red bar that allows the front to detach from the back. So you mount it then wire it separately, then insert it and slide the red bar. It also has a 220v lamp inside that turns on when active. Got it on Amazon for $7 bucks.

https://www.amazon.com/Yohii-Yellow-Momentary-Button-Switch/dp/B07H1B94XD

Bought 25ft of 10-3/G wire to run a 220v outlet to the final location of the transmitter. Going to wire that up this weekend. I then will test the NO/NC action of the power supply up to the breakers. Bought 2 300W incancescent lamps that I will wire in series to put a load on the 220v and let me test. This circuit is supposed to allow me to turn it on and off, but if power is interrupted, it will drop the relay and shut it all down. After that test, I will attach the soft start and variac and see if I can control the brightness of the lamps. I will then be moving on to testing the 2500V HV (very, very carefully!!!   Shocked  Shocked  Shocked )

Started laying out the bias supply chassis also. Need suggestions on grounding. The center tap of the main transformer is where the ground is starting - ground zero. I will have this attached with 10ga thhn stranded green to the ground lug on the power cord. Do I then run a 10ga ground up the stack in a daisy chain to each of the 3 chassis? Or do I run a separate ground to each chassis from the center tap?

On the chassis do I just ground it direct and then use ground points on the terminal lug strips (using star washers) that I will be point to point wiring, or do I run distinct soldered grounds to the lugs in addition to using a grounded chassis?

John


* Switch.JPG (43.5 KB, 658x544 - viewed 362 times.)
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« Reply #109 on: July 24, 2019, 01:25:49 AM »

Please don't trust star washer type grounds to make the rack serve as a ground bus, only to connect the rack to the electrical ground system whether it be a bus or a star. I have chased dozens of loose solder lugs after someone used a cabinet as a ground system via screws with star washers where the machine screw and its bolt became loose over time to where the lug could be moved by hand. If a lockwasher (cut washer) and optional additional nylock nut had been used it would not have happened, but still, a steel cabinet makes a better shield & safety device than a ground, and the good connections offered by a copper wire make a better ground system.
Nylock nuts are costly when used everywhere. I only use them to secure the mains and B- ground to the rack, and the blower motor frame since the blower said it has to be grounded. They are a luxury, not needed when a cut washer is used to maintain tension on a stack of stuff on a bolt but I like the extra peace of mind.

There are are many schools of thought on grounds. The bus and the star are most simple and good choices. Each has good uses. I'm no expert on this topic and the next 3 paragraphs are my opinion which may have many flaws, maybe someone who knows more will kindly comment.

The bus is good for power circuits where a few mV of voltage caused by varying currents in the bus itself won't interference with any of the units using that bus for a ground.
When it is used for a DC and signal return both, then the main ground, which is the mains ground + power supply B- ground + the chassis ground + the signal ground of the weakest signal stage are all tied to a common point, and the bus runs away from that point to serve the circuits having higher and higher currents.

The star is best when there is a variety of large-and-small signal circuits to be grounded. Depending on what is to be rejected, the ground point might be the signal ground or the mains ground, or both. The point at the middle of the star has to be the best ground possible.

Good bypassing or a line filter on the DC power input to a chassis or the mains power input to a chassis is usually enough to prevent RF and high frequency noise from entering the chassis' and that should make either kind of bus acceptable because things like oscillators should have their own regulated power supplies not affected by mains noise or its relation to mains ground or chassis ground. Although the chassis are 'grounded' by means of being bolted in, each chassis should have its B- (C+ in case of bias supply) coming to a terminal on its terminal block. (that is also usually connected under-chassis to the chassis itself, to serve as the mains or safety ground).

Solid is best for stiffness of a bus but stranded takes solder much better.  The two pics show bus and star. There are other more complicated ways but I think your choice of these should be worry-free. The 'bus' picture would easily be the daisy chain you mentioned. The ground bus would daisy chain from one unit to the next.


* 1.png (27.58 KB, 986x658 - viewed 409 times.)

* 2.png (20.03 KB, 816x530 - viewed 377 times.)
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« Reply #110 on: July 26, 2019, 06:44:53 AM »

Patrick,

Think I will borrow this design to protect my screens... I have an unused 6.3v winding on the transformer next to the screen supply. Nice straightforward design.

http://amfone.net/Amforum/index.php?topic=43765.0

John
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« Reply #111 on: July 26, 2019, 11:44:53 PM »

It works great too. Have tripped the screen quite a bit in experiments -totally reliable. The circuit was built into the transmitter By COL Tucker when I got it and includes a lamp and pushbutton reset on the front panel. I merely drew the schematic of the beast.
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« Reply #112 on: July 27, 2019, 07:25:11 AM »

Relay seems to be made of unobtanium. Any pointers to one or a modern equivalent would be helpful.

Guardian X-300-ER overload relay

This relay is so simple and foolproof I really want to try it, but I have a backup plan.

ACS712 current sensor in the negative line of the 400V supply. I will sent the analog signal to the arduino sequencer. While in PTT mode, I will loop on sensing the voltage on an analog input. If the voltage goes too high i.e. too much current, I blow out of the loop and activate the PTT off sequence. I don't think I need to shut off the screen drive with a specific overload relay, just run the full sequencer to off should do it. Seems simple enough. Need to think about it some more. I do have a relay on that line in the schematic and I have extra sequencer capacity so I could preemptively kill the screen then blow the subroutine loop.

Wonder what the MTBF of the relay is WRT the MTBF of the software/hardware stack.  Huh

John
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« Reply #113 on: July 27, 2019, 10:25:05 AM »

MTBF on most relays is 100K operations. Mine is almost 70 years old.
The arduino 100-year paradigm -who can say? Glue a heatsink on the processor, underclock it, add a fan, shield it very well.. No way I would know. Most semiconductors have a life expectancy of at least 20 years according to a previous employer who manufactured them. There might also be a high-rel version. The other parts on the board may have life expectancies too. Keep it cool and free of electrical abuse, right?

Mechanical (dual coil) latching relays:
Mechanical latching relays like the old-style one mentioned occasionally show up on ebay. If I had a spare I would give it.
I guess MTBF, if used to only control the small coil of a power relay, is 100K operations.
Mouser selection tool:
https://www.mouser.com/Electromechanical/Relays/_/N-5g31?P=1z0x216Z1yzxc13Z1z0x3udZ1z0x3bdZ1z0x3tdZ1z0x3txZ1z0x3w0Z1z0x205Z1z0x3ubZ1z0x35nZ1z0x3vzZ1z0x3ylZ1z0vo2rZ1z0x3brZ1z0x1diZ1z0x36rZ1z0spixZ1z0vkvbZ1z0z1s3

Magnetic latching relays:
Some modern latching relays use a magnet to assist and are supposed to therfore save energy.
They latch and reset by the user reversing the polarity of a momentary voltage applied to the coil.
They can suffer from magnet weakening over time.
Mouser selection tool:
https://www.mouser.com/Electromechanical/Relays/_/N-5g31?P=1z0z1wpZ1z0x216Z1z0x3bdZ1yzxc13Z1z0x3udZ1z0x3tdZ1z0x3txZ1z0x3w0Z1z0x205Z1z0x3ubZ1z0x35nZ1z0x3vzZ1z0vo2rZ1z0x3ylZ1z0x3brZ1z0x1diZ1z0x36rZ1z0spixZ1z0vkvb&Ns=Coil+Voltage%7c1


I guess the spec. is how much voltage & current is needed to unlatch the relay. Usually they are kept latched in normal operation since it takes more juice to latch than unlatch, at least on the old one I have.

By no means am I innocent of putting electronic relays in my equipment. The AMF PB time delay units have a board with transistors governed by RC circuits.
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« Reply #114 on: July 28, 2019, 09:40:20 AM »

Patrick,

After looking at your schematic more closely, I see that it needs an ac 6V coil to latch. Does it also have a AC coil for the reset?

Galco RR2KP-U-AC6 - Latching Relay, DPDT, 10A, 6VAC Coil

This company seems to be the successor to Guardian. I see how to use this relay for the latch of the transformer primary. Not sure if if will work on the negative side using a WW pot with an AC coil.

I have 24VDC available so I could use a 24V DC rated coil pair. 24V to latch for operation. Then set the trip at 150ma. That equates to a 190 ohm R in parallel with the reset coil to give a 19.2 voltage drop that will trip the reset at it's 80% value. At 80ma, the drop is 10V which is not enough to trip the coil. A 400 ohm 5W WW pot should give me plenty of capacity.

Am I on the right track?

John

* RR2KPSeries.pdf (277.55 KB - downloaded 189 times.)
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« Reply #115 on: July 28, 2019, 10:33:05 AM »

Continuing to wire the HV today. Thinking about spark gaps.

Attached is the preliminary thoughts. The top of the big iron have flanges that is perfect for attaching lexan sheeting that I can place HV parts on. I did this with the diode strings. I thought about a common metal AL strip grounded to the HV center tap. I would place 3 spark gaps along this strip, each having a metal AL strip that has an adjustable elongated hole. That way I can adjust the gaps appropriately. I may then make a clear LEXAN box to cover it.

I plan to place gaps at the CT of the MOD primary (2), the Plate choke side of the MOD secondary (5), and the junction of the heising choke where it connects to the caps (4).

Is this a good plan and enough protection for the mod iron?

John


* Spark Gaps.jpg (314.29 KB, 1686x2552 - viewed 413 times.)
* 813 Transmitter.pdf (185.53 KB - downloaded 191 times.)
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« Reply #116 on: July 28, 2019, 10:30:42 PM »

Patrick,

After looking at your schematic more closely, I see that it needs an ac 6V coil to latch. Does it also have a AC coil for the reset?

Galco RR2KP-U-AC6 - Latching Relay, DPDT, 10A, 6VAC Coil

This company seems to be the successor to Guardian. I see how to use this relay for the latch of the transformer primary. Not sure if if will work on the negative side using a WW pot with an AC coil.

I have 24VDC available so I could use a 24V DC rated coil pair. 24V to latch for operation. Then set the trip at 150ma. That equates to a 190 ohm R in parallel with the reset coil to give a 19.2 voltage drop that will trip the reset at it's 80% value. At 80ma, the drop is 10V which is not enough to trip the coil. A 400 ohm 5W WW pot should give me plenty of capacity.

Am I on the right track?

John

The reset, or 'trip' coil for the screen current protection action is DC type appropriate for DC screen current. I don't think I have the voltage/current specs on it or don't remember. I am sure the AC 6.3V latch coil was mainly for convenience when 6.3VAC was more common.

If mechanical latching relays are what you want then I think you are totally on the right track there. Those relays are really appropriate-looking as well. If you have DC power then it's perfect since the screen current is direct.
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« Reply #117 on: July 29, 2019, 02:08:02 PM »

you can sumulate mechanical latching relays rather easily if you will integrate needed funtions into the hv start / stop relay (regular non-latching type):

                                                       HV on                                       HV off      trip relay
                                                         ...|...
                       .................................o   o...............{)()()().............o..|...o.....o....>o.........
                       |               |                   no        |          coil                    nc            nc            |
                     pwr             |          no                 |                                                                 |  
                     supply         ........o        o.............                                                                  |
                       |                         \    relay                                                                             |
                       |                          \   seal in                                                                           |
                       |...|


this is crude and simplified but shud get the idee across .... without the seal in contact the hv relay only remains on while the hv on button is pushed.... as many trip elements as you need can be used by adding normally closed contacts in series

(please connect the bottom common line across the page ...somphin in the editor won't let me do this  Huh Huh Huh
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« Reply #118 on: July 29, 2019, 09:39:34 PM »

slight rearrangement due to LTspice symbols on hand, but includes the pesky wire.
240VAC coils all, except trip relay which is to be chosen as desired.
suggest magnetic breakers instead of fuses. cost more to put in but trip as fast as fuses blow and cost nothing to reset.


* overload-cut-plate.png (41.49 KB, 1437x766 - viewed 393 times.)
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« Reply #119 on: July 30, 2019, 06:33:43 AM »

You guys are going to have to break this down for me a bit.

Here is what I thought I was doing - running along nicely until the HV supply blows a HV fuse (not the breakers). Immediately thereafter the screen current goes quickly above nominal. This should trip the overload relay and shut down the 400V screen thus saving the tubes. Perhaps I should have my sequencer see this event and then shut down everything else or maybe I see it go dead and release the PTT manually.

Why do I want to add trip functionality to the 240V input to the HV PS? The HV is already off.

Please explain...not understanding.

thanks,
John
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« Reply #120 on: July 30, 2019, 04:35:52 PM »

  My Collins KW-1,   primary of 500 VDC screen power supply is hooked to the primary of the
2,400 VDC plate supply. If the plate supply goes down, the screen goes down also. There is a
 overload trip relay, in series with negative high voltage to final tubes which has a set of contacts that the screen voltage thru, so if it trips out, screen voltage disconnected.

    In the control panel portion, there is a tune, operate switch, In tune , the 500vdc, is disconnect from the wiring to the rf screens and the rf screens are chassis grounded. In operate, the screen voltage wiring direct to the tubes.

   This is nice for tuning for rf resonance, you don't have cherry red tubes, plate meter pegged
while you trying to dip and load the amp .I can dip , load to 150 or so milliamps, switch to
operate, screen voltage on tubes, 300 + plate current.
 
  The AC circuit, fused, both sides  thru 25 amp  motor starting relay controlled by a HV
standby and then manual or ptt transmit

Bob  W8LXJ

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« Reply #121 on: July 31, 2019, 12:07:44 AM »

 My Collins KW-1,   primary of 500 VDC screen power supply is hooked to the primary of the
2,400 VDC plate supply. If the plate supply goes down, the screen goes down also. There is a
 overload trip relay, in series with negative high voltage to final tubes which has a set of contacts that the screen voltage thru, so if it trips out, screen voltage disconnected.
   Bob  W8LXJ


Hi Bob,

Sounds like a cool setup. The screen primary winding connected to the HV primary is a good idea.


I don't have the schematic, but what would happen if the HV secondary winding opened up or the HV diodes open up so there was no HV on the tube plate, but there was still AC primary voltage - so that the screen voltage was still on the tube?

Would the negative lead relay cover this or not?  IE, if HV is not there, does that relay drop out?

John: I open the PTT keying circuit whenever there is an overload fault. With tubes, usually the voltages will bleed off and not cause any problems. Solid state stuff will not have the same sense of humor, however.

I use Hall effect devices in series with the negative DC leads of the plates, grids and screens of both the finals and modulators. They are preset to trip on current overloads and open the PTT circuit automatically when faults occur. There are cheap Chinese Hall effect devices on eBay that are easy to set up and trigger a latching multi-relay board also found on eBay.


To answer an older question:  Yaz IV,  is my 2 1/2 year old English Springer Spaniel and he goes sailing and kayaking with me on the freshwater lakes and rivers here in CT. I took Yaz III out on the rough ocean in RI a few years ago and it was quite sporting, but he loved it... :-)

Your plans are coming along very well there. I see you decided to use the pi-network grid input circuit with no neutralization. With a tetrode, it will work very well - no worries if you build it like Chuck's layout.

T


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Use an "AM Courtesy Filter" to limit transmit audio bandwidth  +-4.5 KHz, +-6.0 KHz or +-8.0 KHz when needed.  Easily done in DSP.

Wise Words : "I'm as old as I've ever been... and I'm as young as I'll ever be."

There's nothing like an old dog.
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Patrick J. / KD5OEI
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« Reply #122 on: August 02, 2019, 09:36:27 AM »

You guys are going to have to break this down for me a bit.

Here is what I thought I was doing - running along nicely until the HV supply blows a HV fuse (not the breakers). Immediately thereafter the screen current goes quickly above nominal. This should trip the overload relay and shut down the 400V screen thus saving the tubes. Perhaps I should have my sequencer see this event and then shut down everything else or maybe I see it go dead and release the PTT manually.

Why do I want to add trip functionality to the 240V input to the HV PS? The HV is already off.

Please explain...not understanding.

thanks,
John

yes, you can do exactly that. The transmitter here will key up with the screen overload tripped. With the expected results of little to no output.

Sometimes another failure will cause excessive screen curent, like a tuning/loading issue or some fail in the HV reaching the plate of the protected tube, while the HV supply is still on and otherwise running. Some component failure like a HV fuse blowing or plate choke opening or even bumping the loading control could cause the screen current to go up.

The only thing the protection has to really do is stop the excessive screen current and there are so many choices on how to do it.

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« Reply #123 on: August 03, 2019, 09:30:41 AM »

So, if the main concern is loss of plate voltage causing screen current issues, wouldn’t the simplest solution be a voltage divider and a relay/sense line on the plate voltage to enable the screen supply? No unobtainium overload relay needed. You’re already using a fancy sequencer thingy right? Just another input to consider, include a brief wait on power-up only to let the plate supply caps charge or the screen won’t ever enable, and code it so the screen enable is latched off once tripped.

It seems to me sometimes, in our quest for perfect, things get way too complicated. Ive started weighing the cost of the protection and time to implement it, vs the cost of the parts being protected.....I want to make RF and get on the air...someday...

Ed
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Ed, K8DI, warming the air with RF, and working on lighting the shack with thoriated tungsten and mercury vapor...
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« Reply #124 on: August 03, 2019, 12:28:35 PM »

The problem with sensing the screen trip off the high voltage is WHERE do to you sense the HV?  If it is anywhere but at the plate cap of the tube, then we could have a failure.  IE, there are many places the HV supply and HV circuit could fail - anywhere from the 240 AC up to the plate cap. And what if the factory plate cap weld goes intermittent sitting on the tube glass? I've had that happen too...  Plus, there's RF to contend with at any point past the bottom of the plate choke.

The best way to protect the screen is with a current sensor in series with the screen circuit or clamp tube, etc.   There are many ways but my ultimate method is using a tiny Hall effect device that senses the magnetic field thru a wire and can then trip off the screen in any way you desire. Then the HV can do anything it wants independent of the screen.

As I mentioned before, I use six Hall effect devices into a multi-latching relay board for the grid/screen/ plate circuits of BOTH the modulators and finals. This way it becomes "uniform" for all devices with the same simple circuit employed everywhere ... easy to use and easy to remember one circuit design when troubleshooting the whole protection system.

T
Logged

Use an "AM Courtesy Filter" to limit transmit audio bandwidth  +-4.5 KHz, +-6.0 KHz or +-8.0 KHz when needed.  Easily done in DSP.

Wise Words : "I'm as old as I've ever been... and I'm as young as I'll ever be."

There's nothing like an old dog.
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