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#1
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HT Relay
I am trying to select a relay for a delayed HT switch (which will also
discharge the HT when off). Most relays I can find have contacts rated at 250VAC which translates into a peak of about 350V. However, data is scarce on what dc voltage these relays can switch. So far I have found only one that gives a dc current versus voltage curve and that stops at 210V dc (and 200mA) and I really want to be able to switch up to 350V at up to 200mA. The rest just give a dc voltage at max current value. So, I am guessing that this problem has been faced before and there are relays that are known to work fine in this application. Any recommendations? By the way I prefer a 5V coil. Cheers Ian |
#2
Posted to rec.audio.tubes
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HT Relay
"Ian Bell" I am trying to select a relay for a delayed HT switch (which will also discharge the HT when off). Most relays I can find have contacts rated at 250VAC which translates into a peak of about 350V. However, data is scarce on what dc voltage these relays can switch. So far I have found only one that gives a dc current versus voltage curve and that stops at 210V dc (and 200mA) and I really want to be able to switch up to 350V at up to 200mA. The rest just give a dc voltage at max current value. So, I am guessing that this problem has been faced before and there are relays that are known to work fine in this application. Any recommendations? ** Relay contacts are rated in *BREAKING* capacity - you IDIOT. You seem to only need the relay to *MAKE* a DC circuit - so no issue exists at all. Play safe - and switch the ****ing AC. IMBECILE !! ..... Phil |
#3
Posted to rec.audio.tubes
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HT Relay
Phil Allison wrote:
"Ian Bell" I am trying to select a relay for a delayed HT switch (which will also discharge the HT when off). Most relays I can find have contacts rated at 250VAC which translates into a peak of about 350V. However, data is scarce on what dc voltage these relays can switch. So far I have found only one that gives a dc current versus voltage curve and that stops at 210V dc (and 200mA) and I really want to be able to switch up to 350V at up to 200mA. The rest just give a dc voltage at max current value. So, I am guessing that this problem has been faced before and there are relays that are known to work fine in this application. Any recommendations? ** Relay contacts are rated in *BREAKING* capacity - you IDIOT. You seem to only need the relay to *MAKE* a DC circuit - so no issue exists at all. No, I need it to break it too - note the bit about discharging when HT is off - it needs to break the normal load and make the discharge load ( and vice versa) Play safe - and switch the ****ing AC. Are you suggesting I switch the ac secondary? Cheers Ian IMBECILE !! .... Phil |
#4
Posted to rec.audio.tubes
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HT Relay
"Ian Bell" wrote in message
I am trying to select a relay for a delayed HT switch (which will also discharge the HT when off). Most relays I can find have contacts rated at 250VAC which translates into a peak of about 350V. However, data is scarce on what dc voltage these relays can switch. So far I have found only one that gives a dc current versus voltage curve and that stops at 210V dc (and 200mA) and I really want to be able to switch up to 350V at up to 200mA. The rest just give a dc voltage at max current value. So, I am guessing that this problem has been faced before and there are relays that are known to work fine in this application. Any recommendations? By the way I prefer a 5V coil. Deepending on your application, couldn't you implement the switch electronically with a series tube, perhaps even a thyratron? |
#5
Posted to rec.audio.tubes
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HT Relay
"Ian Bell" Phil Allison wrote: I am trying to select a relay for a delayed HT switch (which will also discharge the HT when off). Most relays I can find have contacts rated at 250VAC which translates into a peak of about 350V. However, data is scarce on what dc voltage these relays can switch. So far I have found only one that gives a dc current versus voltage curve and that stops at 210V dc (and 200mA) and I really want to be able to switch up to 350V at up to 200mA. The rest just give a dc voltage at max current value. So, I am guessing that this problem has been faced before and there are relays that are known to work fine in this application. Any recommendations? ** Relay contacts are rated in *BREAKING* capacity - you IDIOT. You seem to only need the relay to *MAKE* a DC circuit - so no issue exists at all. No, I need it to break it too - note the bit about discharging when HT is off - it needs to break the normal load and make the discharge load ( and vice versa) ** Post a schematic - you IDIOT. Still sounds like you are NOT breaking anything like 350 volts. ..... Phil |
#6
Posted to rec.audio.tubes
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HT Relay
Phil Allison wrote:
"Ian Bell" Phil Allison wrote: I am trying to select a relay for a delayed HT switch (which will also discharge the HT when off). Most relays I can find have contacts rated at 250VAC which translates into a peak of about 350V. However, data is scarce on what dc voltage these relays can switch. So far I have found only one that gives a dc current versus voltage curve and that stops at 210V dc (and 200mA) and I really want to be able to switch up to 350V at up to 200mA. The rest just give a dc voltage at max current value. So, I am guessing that this problem has been faced before and there are relays that are known to work fine in this application. Any recommendations? ** Relay contacts are rated in *BREAKING* capacity - you IDIOT. You seem to only need the relay to *MAKE* a DC circuit - so no issue exists at all. No, I need it to break it too - note the bit about discharging when HT is off - it needs to break the normal load and make the discharge load ( and vice versa) ** Post a schematic - you IDIOT. Still sounds like you are NOT breaking anything like 350 volts. It is easy enough to describe. The relay common is connected to the HT supply (semiconductor rectifiers and RC smoothing). The NC contact is connected to ground via a resistor which is used to discharge the HT supply caps when power is turned off. The NO contact goes to the circuit to be powered by the supply. On power up the heater supply comes up right away but the relay is held off for say 30 secs. Then the relay is switched and HT is removed from the discharge R and connected to the circuit. When mains power is removed, the relay drops out straight away and the discharge resistor is connected across the HT supply. Cheers Ian .... Phil |
#7
Posted to rec.audio.tubes
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HT Relay
"Ian Bell" wrote in message ... I am trying to select a relay for a delayed HT switch (which will also discharge the HT when off). Most relays I can find have contacts rated at 250VAC which translates into a peak of about 350V. However, data is scarce on what dc voltage these relays can switch. So far I have found only one that gives a dc current versus voltage curve and that stops at 210V dc (and 200mA) and I really want to be able to switch up to 350V at up to 200mA. The rest just give a dc voltage at max current value. So, I am guessing that this problem has been faced before and there are relays that are known to work fine in this application. Any recommendations? By the way I prefer a 5V coil. **Unless you have A LOT of cash, stick to switching AC. Most relays are rated for a maximum of 27 VDC, regardless of the AC Voltage rating. Contrary to your comments, ALL proper relay manufacturers clearly spell out the maximum DC switching Voltage. Invariably, it will be less than 30 Volts. -- Trevor Wilson www.rageaudio.com.au |
#8
Posted to rec.audio.tubes
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HT Relay
"Ian Bell"
Phil Allison wrote: ** Post a schematic - you IDIOT. Still sounds like you are NOT breaking anything like 350 volts. It is easy enough to describe. The relay common is connected to the HT supply (semiconductor rectifiers and RC smoothing). The NC contact is connected to ground via a resistor which is used to discharge the HT supply caps when power is turned off. The NO contact goes to the circuit to be powered by the supply. On power up the heater supply comes up right away but the relay is held off for say 30 secs. Then the relay is switched and HT is removed from the discharge R and connected to the circuit. When mains power is removed, the relay drops out straight away and the discharge resistor is connected across the HT supply. ** Everything depends on the "circuit" that is being powered - that is why a schem is needed. The breaking capacity needed from the relay is NOT simply the voltage and current being supplied to the load prior to opening. The relay spec you quoted says the unit is OK to 210 volts DC ( across the contacts) and 200mA - so the question is, with 140 volts (ie 350 - 210) supplied to your "circuit" will it still draw 200mA ?? If not, the there will likely be no arcing problem as the conditions do not exist for continuous arcing. Also, if you add a suitable electro cap to the supply rail of the "circuit" - that will prevent arcing entirely !!! As little as 4.7uF should hold the voltage up on the "circuit" side long enough ( say 1mS ) for the relay contacts to separate and be arc free. IOW - go try a damn relay and stop playing dumb hypotheticals with misunderstood specs. ..... Phil |
#9
Posted to rec.audio.tubes
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HT Relay
Phil Allison wrote:
"Ian Bell" Phil Allison wrote: ** Post a schematic - you IDIOT. Still sounds like you are NOT breaking anything like 350 volts. It is easy enough to describe. The relay common is connected to the HT supply (semiconductor rectifiers and RC smoothing). The NC contact is connected to ground via a resistor which is used to discharge the HT supply caps when power is turned off. The NO contact goes to the circuit to be powered by the supply. On power up the heater supply comes up right away but the relay is held off for say 30 secs. Then the relay is switched and HT is removed from the discharge R and connected to the circuit. When mains power is removed, the relay drops out straight away and the discharge resistor is connected across the HT supply. ** Everything depends on the "circuit" that is being powered - that is why a schem is needed. The breaking capacity needed from the relay is NOT simply the voltage and current being supplied to the load prior to opening. The relay spec you quoted says the unit is OK to 210 volts DC ( across the contacts) and 200mA - so the question is, with 140 volts (ie 350 - 210) supplied to your "circuit" will it still draw 200mA ?? If not, the there will likely be no arcing problem as the conditions do not exist for continuous arcing. Also, if you add a suitable electro cap to the supply rail of the "circuit" - that will prevent arcing entirely !!! As little as 4.7uF should hold the voltage up on the "circuit" side long enough ( say 1mS ) for the relay contacts to separate and be arc free. IOW - go try a damn relay and stop playing dumb hypotheticals with misunderstood specs. .... Phil Thanks for the input Phil. You have given me much to think about. I have no experience of using relays to switch HT (but you already guessed that) so the exact meaning of relay switching specs and the problems they experience when used outside their obvious (but limited) specified conditions is something I need to learn. I was planning to try a relay or two as you suggest but I would like to be in a position to apply this technique more generally so I need to understand what is going one as well as merely having a working solution for one specific applications. If you could point me to any written material on the subject I would be grateful. Cheers Ian |
#10
Posted to rec.audio.tubes
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HT Relay
On Thu, 24 Dec 2009 14:09:07 +0000, Ian Bell wrote:
I am trying to select a relay for a delayed HT switch (which will also discharge the HT when off). Most relays I can find have contacts rated at 250VAC which translates into a peak of about 350V. However, data is scarce on what dc voltage these relays can switch. So far I have found only one that gives a dc current versus voltage curve and that stops at 210V dc (and 200mA) and I really want to be able to switch up to 350V at up to 200mA. The rest just give a dc voltage at max current value. So, I am guessing that this problem has been faced before and there are relays that are known to work fine in this application. Any recommendations? By the way I prefer a 5V coil. You've probably got all the info you need really, but the contact voltage rating of a relay depends on the air gap. When switching AC any arc only lasts until the voltage passes through zero, at which point the arc extinguishes naturally. If the voltage is DC then the arc can maintain indefinitely. You can increase the DC voltage switching capability by connecting contacts in series, providing that they make and break simultaneously. "Proper" DC switching devices often have powerful magnets on each side of the contact gap. These pull the arc sideways on breaking, allowing a closer contact gap than would be possible otherwise. You also need to make very sure that the coil-contact voltage rating is safe for your application. e.g. using an Omron MK2S ("octal" 2p) relay with both n.o. contacts in series you get 250VDC per contact with up to 2500VAC contacts to coil isolation. I would suggest that you connect the common of the c/o contact to earth and switch the negative side of the supply. The n.c. contact can then switch the bottom end of a resistor up to HT+. This way the relay coil and frame can be at low voltage. Relay info: http://industrial.omron.co.uk/en/pro...ng_components/ electromechanical_relays/industrial_plug_in_relays/mk-s/default.html -- Mick (Working in a M$-free zone!) Web: http://www.nascom.info Filtering everything posted from googlegroups to kill spam. |
#11
Posted to rec.audio.tubes
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HT Relay
"mick the prick " You also need to make very sure that the coil-contact voltage rating is safe for your application. e.g. using an Omron MK2S ("octal" 2p) relay with both n.o. contacts in series you get 250VDC per contact .. ** Omron do NOT state the switching capacity at 250V DC. With the standard de-rating factors applied - it is likely only in the tens of mAs. Idiot. ...... Phil |
#12
Posted to rec.audio.tubes
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HT Relay
On Sat, 26 Dec 2009 10:11:46 +1100, Phil Allison wrote:
"mick the prick " You also need to make very sure that the coil-contact voltage rating is safe for your application. e.g. using an Omron MK2S ("octal" 2p) relay with both n.o. contacts in series you get 250VDC per contact .. ** Omron do NOT state the switching capacity at 250V DC. With the standard de-rating factors applied - it is likely only in the tens of mAs. Idiot. No need to be offencive, Phil. Just because Omron don't provide a full data sheet on the web. They state a maximum switching voltage of 250VDC and a maximum switching load of 300W on a n.o. contact (half of this for the n.c. contact). That works out at 1.2A and 0.6A respectively (it won't be that high in real life), if you can't be bothered with the maths. Admittedly though, they also give a DC rating of 5A @ 30VDC but the DC loading doesn't follow a linear curve against the voltage as you probably know. If you would care to check out an alternative similar style relay (with much better documentation), the Finder 60 series shows a graph, with DC ratings up to 220v for 1, 2 & 3 contacts in series, and shows my point about the non-linear curve very well. The 60.12 is a very similar unit to the Omron and is used as a direct replacement in most cases. Finder link: http://www.findernet.com/en/products...rie=60&lang=en Both the relay spec pdf and the General Technical Information pages are worth a look. -- Mick (Working in a M$-free zone!) Web: http://www.nascom.info Filtering everything posted from googlegroups to kill spam. |
#13
Posted to rec.audio.tubes
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HT Relay
"mick the prick "
You also need to make very sure that the coil-contact voltage rating is safe for your application. e.g. using an Omron MK2S ("octal" 2p) relay with both n.o. contacts in series you get 250VDC per contact .. ** Omron do NOT state the switching capacity at 250V DC. With the standard de-rating factors applied - it is likely only in the tens of mAs. Idiot. No need to be offencive, ** Stop posting crazy BULL**** !! And I will not need to SHUT YOU UP. They state a maximum switching voltage of 250VDC and a maximum switching load of 300W on a n.o. contact (half of this for the n.c. contact). ** Again - you are just making up bull**** data. If you would care to check out an alternative similar style relay (with much better documentation), the Finder 60 series shows a graph, with DC ratings up to 220v for 1, 2 & 3 contacts in series, ** For one set of contacts - the max breaking rating is just over 100mA. Funny how you did not want to POST that fact - eh ??? Drop Dead you DAMN LIAR !!!! .... Phil |
#14
Posted to rec.audio.tubes
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HT Relay
On Sat, 26 Dec 2009 20:58:53 +1100, Phil Allison wrote:
snip ** Stop posting crazy BULL**** !! And I will not need to SHUT YOU UP. They state a maximum switching voltage of 250VDC and a maximum switching load of 300W on a n.o. contact (half of this for the n.c. contact). ** Again - you are just making up bull**** data. Yes pointless phil, I made it up from the data sheet... Yawn If you would care to check out an alternative similar style relay (with much better documentation), the Finder 60 series shows a graph, with DC ratings up to 220v for 1, 2 & 3 contacts in series, ** For one set of contacts - the max breaking rating is just over 100mA. Whee!!! It can read a graph! Funny how you did not want to POST that fact - eh ??? Drop Dead you DAMN LIAR !!!! Pillock... That's why we series up multiple contacts then, isn't it? Look at the damn graph again! For 2 contacts in series it's 400mA and for 3 contacts its about 900mA. Remember that you can allow up to 250v *per contact* (although I don't personally like using the 3-pole relay like this). You are ok switching 400mA resistive at 440VDC with a safety margin if you series up both contacts on a 2-pole relay. Also, keep the same polarity on the contacts to reduce stresses in the insulation. -- Mick (Working in a M$-free zone!) Web: http://www.nascom.info Filtering everything posted from googlegroups to kill spam. |
#15
Posted to rec.audio.tubes
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mick the PRICK
" mick the PRICK " Look at the damn graph again! For 2 contacts in series it's 400mA and for 3 contacts its about 900mA. Remember that you can allow up to 250v *per contact* ** Look at the damn graph again - you STINKING LIAR !! The max voltage is only 220V for ALL three curves and conditions. http://www.findernet.com/comuni/pdf/S60EN.pdf See middle right of page 5. **** OFF to HELL - YOU PIG IGNORANT DAMN TROLL ...... Phil |
#16
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mick the PRICK
On Sat, 26 Dec 2009 23:57:38 +1100, Phil Allison wrote:
" mick the PRICK " Look at the damn graph again! For 2 contacts in series it's 400mA and for 3 contacts its about 900mA. Remember that you can allow up to 250v *per contact* ** Look at the damn graph again - you STINKING LIAR !! The max voltage is only 220V for ALL three curves and conditions. http://www.findernet.com/comuni/pdf/S60EN.pdf See middle right of page 5. **** OFF to HELL - YOU PIG IGNORANT DAMN TROLL See page iv of the General Technical document. Under DC1 in table 1 it states "The switching voltage at the same current can be doubled by wiring 2 contacts in series". And a Very Merry Christmas to you too, Phil! :-) -- Mick (Working in a M$-free zone!) Web: http://www.nascom.info Filtering everything posted from googlegroups to kill spam. |
#17
Posted to rec.audio.tubes
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mick the PRICK
On Sat, 26 Dec 2009 23:57:38 +1100, "Phil Allison"
wrote: " mick the PRICK " Look at the damn graph again! For 2 contacts in series it's 400mA and for 3 contacts its about 900mA. Remember that you can allow up to 250v *per contact* ** Look at the damn graph again - you STINKING LIAR !! The max voltage is only 220V for ALL three curves and conditions. http://www.findernet.com/comuni/pdf/S60EN.pdf See middle right of page 5. **** OFF to HELL - YOU PIG IGNORANT DAMN TROLL ..... Phil Hello Phil, I think that it would be more charitable to say that he was mistaken. Why must you over react to any comment that you see is mistaken? Kind regards Bill Ramsay |
#18
Posted to rec.audio.tubes
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mick in forgiving mood
On Sun, 27 Dec 2009 08:14:33 +1300, beel wrote:
snip I think that it would be more charitable to say that he was mistaken. Why must you over react to any comment that you see is mistaken? That's quite typical of Phil - something that I'm used to seeing a lot of on here! It's just the way he is (and he'll probably insult me again for saying that!). :-) -- Mick (Working in a M$-free zone!) Web: http://www.nascom.info Filtering everything posted from googlegroups to kill spam. |
#19
Posted to rec.audio.tubes
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mick the PRICK
Hello Phil, I think that it would be more charitable to say that he was mistaken. ** What a fool like you thinks does not matter. ..... Phil |
#20
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mick the PRICK
Phil needs attention. He didn't get enough of it as a child so he still
trying to get the attention he needs to grow up and be a man He's got a long way to go. Eddie "Phil Allison" wrote in message ... Hello Phil, I think that it would be more charitable to say that he was mistaken. ** What a fool like you thinks does not matter. ..... Phil |
#21
Posted to rec.audio.tubes
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mick the PRICK
On Sun, 27 Dec 2009 10:15:03 +1100, "Phil Allison"
wrote: Hello Phil, I think that it would be more charitable to say that he was mistaken. ** What a fool like you thinks does not matter. .... Phil Mighty fine words for someone who does not know me. So it's being foolish to suggest that you lack charity, is it? My Grandmother used to tell me that politeness costs nothing. Shouting and being generally obnoxious seems to be your stock in trade. It only illuminates either the paucity of your vocabulary, mental state or general unwellness. Which is it? Kind regards Bill. |
#22
Posted to rec.audio.tubes
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mick the PRICK
** What a fool like you thinks does not matter. Mighty fine words for someone who does not know me. ** You are very well known to me " Bill Ramsay" - as a complete ASSHOLE !! ...... Phil |
#23
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mick the PRICK
On Sun, 27 Dec 2009 15:54:54 +1100, "Phil Allison"
wrote: ** What a fool like you thinks does not matter. Mighty fine words for someone who does not know me. ** You are very well known to me " Bill Ramsay" - as a complete ASSHOLE !! ..... Phil oh sweetie, our secret is out!!!! what is it that makes you so prescient? Anyway, who gives a toss what a feeble minded vertically integrated onanist like you 'thinks'. love and hugs, tell you what, shall we meet in the usual place?, you stand under the railway clock with your little face going purple in rage, and of course, the badger stuck up your bum. Bill |
#24
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mick the PRICK
** What a fool like you thinks does not matter. Mighty fine words for someone who does not know me. ** You are very well known to me " Bill Ramsay" - as a complete ASSHOLE !! FOAD - you moronic PIG. ...... Phil |
#26
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mick the PRICK
On Sun, 27 Dec 2009 20:32:52 +1100, "Phil Allison"
wrote: ** What a fool like you thinks does not matter. Mighty fine words for someone who does not know me. ** You are very well known to me " Bill Ramsay" - as a complete ASSHOLE !! FOAD - you moronic PIG. ..... Phil tell me phil do you still wear your full faced motor cycle helmet when you meet people? I've heard you have to do that otherwise you'd have a face like a well slapped arse! |
#27
Posted to rec.audio.tubes
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mick the PRICK
On Sun, 27 Dec 2009 12:08:12 +0000, Ian Bell
wrote: wrote: On Sun, 27 Dec 2009 15:54:54 +1100, "Phil Allison" wrote: ** What a fool like you thinks does not matter. Mighty fine words for someone who does not know me. ** You are very well known to me " Bill Ramsay" - as a complete ASSHOLE !! ..... Phil oh sweetie, our secret is out!!!! what is it that makes you so prescient? Anyway, who gives a toss what a feeble minded vertically integrated onanist like you 'thinks'. love and hugs, tell you what, shall we meet in the usual place?, you stand under the railway clock with your little face going purple in rage, and of course, the badger stuck up your bum. Bill LOl!! I just love the bit about the badger up his bum LOL made my day. Thanks Mate Ian nil problemos, I do my best. Kind regards Bill. |
#28
Posted to rec.audio.tubes
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HT Relay
Phil Allison wrote:
It is easy enough to describe. The relay common is connected to the HT supply (semiconductor rectifiers and RC smoothing). The NC contact is connected to ground via a resistor which is used to discharge the HT supply caps when power is turned off. The NO contact goes to the circuit to be powered by the supply. On power up the heater supply comes up right away but the relay is held off for say 30 secs. Then the relay is switched and HT is removed from the discharge R and connected to the circuit. When mains power is removed, the relay drops out straight away and the discharge resistor is connected across the HT supply. ** Everything depends on the "circuit" that is being powered - that is why a schem is needed. The breaking capacity needed from the relay is NOT simply the voltage and current being supplied to the load prior to opening. Quite. And the exact shape of current and voltage over time, for opening and closing conditions, can be modified by changes to the circuit, which multiplies the complexity of the selection problem. In these situations, I guess a professional would copy whatever is commonly done. The relay spec you quoted says the unit is OK to 210 volts DC ( across the contacts) and 200mA - so the question is, with 140 volts (ie 350 - 210) supplied to your "circuit" will it still draw 200mA ?? If not, the there will likely be no arcing problem as the conditions do not exist for continuous arcing. Also, if you add a suitable electro cap to the supply rail of the "circuit" - that will prevent arcing entirely !!! As little as 4.7uF should hold the voltage up on the "circuit" side long enough ( say 1mS ) for the relay contacts to separate and be arc free. IOW - go try a damn relay and stop playing dumb hypotheticals with misunderstood specs. I quite like dumb hypotheticals. They don't *have* to be dumb...any hypotheticals will do. What else is worth discussing? Ian could do what I guess a professional would do and ask his suppliers. Some may have application guides available on their sites, as may some manufacturers. There are so many different relays on the market that specification is presumably very narrow. DIY testing isn't very practical, because many relays will do the job, but some may not do it for very long. Ian would need to build a tester, and test a lot of relays, a lot of times each. The prospect of failure raises the question, incidentally, of its possible consequences. The circuit must be able to tolerate a contact stuck in either the open or closed position. An advantage of using two in series is that it's very unlikely that both would stick closed. A SCR or other semiconductor solution may be worth considering. They aren't so various, so I guess specification must be broader, or applications narrower. Their data sheets are probably pretty extensive too. Although I'm loath to point this out to a self-proclaimed professional who hopes to profit from his electronics business, contact specifications for the two different applications he cites are quite different, as are the consequences of failure, so using a single relay is unlikely to be an optimum solution. Using a relay to drain HT capacitors is unnecessary, and a simple relay or SCR on the primary side of a separate HT transformer would be a sensible and common enough solution to make selection easy. Ian |
#29
Posted to rec.audio.tubes
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HT Relay
"Ian Iveson" ** Ian Bell has posted just two objectives: 1. To switch off the HT as soon as the AC power is removed from the PSU. 2. The switch of the HT if the PSU connector is removed from the load device. Requirement 1 is a nonsense. Requirement 2 can be done with any relay cos it is " dry " switching. Bell is a total MORON !!! ..... Phil |
#30
Posted to rec.audio.tubes
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HT Relay
On Mon, 28 Dec 2009 14:50:24 +1100, "Phil Allison"
wrote: "Ian Iveson" ** Ian Bell has posted just two objectives: 1. To switch off the HT as soon as the AC power is removed from the PSU. 2. The switch of the HT if the PSU connector is removed from the load device. Requirement 1 is a nonsense. Requirement 2 can be done with any relay cos it is " dry " switching. Bell is a total MORON !!! .... Phil an alternative way to say this of course, could be. 1. I don't think that's really necessary as .................... 2. This is a very good idea, any relay will do for this purpose as it is dry switching. Kind regards etc. why don't you try that for a change? you'll be surprised by the more pleasant reaction you'll get. You'll also be able to take off that full face helmet when you go out in public. |
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