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PC power supplies
It is my understanding that PC powersupplies take 120 AC and run it through
a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work |
#2
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PC power supplies
"Jimmy" wrote in message
m... It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Where do you get your 300 Volt Direct Current (vdc) supply from? That's Direct Current, not Alternating Current (AC) It sure as hell doesn't come out from a wall outlet, as mains supplied power is AC not DC. If it is VDC then it could be applied straight across the large Filter Capacitors. Making sure you have the correct polarity applied. Positive rail to Positive and Negative supply rail applied to Negative, else smoke and fire or bodily damage may result. Sounds like a dangerous project to me. |
#3
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PC power supplies
Jimmy wrote:
It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Warning! what are you trying to dO? send smoke signals? Who was telling you about 300vdc? to power up a PC? A pc uses +5Vdc and +12VDc. so forget about your idea. |
#4
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PC power supplies
Jimmy wrote: It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work let everybody know when you are ready test so we know why the power goes down again. Hopefully we can also see the smoke from your place. rw |
#5
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PC power supplies
On Mon, 20 Oct 2003 00:15:10 +0000, Jimmy wrote:
It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. This is incorrect. PC Power supplies take the power from the wall and turn it into DC, (up to) 400 _Watts_ or so (depending on the power supply). This is what my Power Supply provides on various leads: +3.3V @ 28A +5V @ 40A +12V @ 18A -12V @ 1A -5V @ 1A +5SB @ 3A (I admit I don't know what the SB means... I'm just reading what's on the power supply...) This is all maximum output. -- Lenroc |
#6
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PC power supplies
I agree with Spudley - its a dangerous thing to do. You are correct that
most offline switchers have this type of direct rectifier front end. While this might work with a particular supply, you can't make assumptions about it without detailed info on the supply you are using. Additionally, what happens if the supply fails and someone replaces it with a different type or model? There are no guarantees on internal polarity, or current ratings of the various input devices. You should look carefully at the DC ratings of the input line filter components, (both coils and caps). I bet the "Y" capacitors on the input lines are going to have a tough time with 300 VDC. They are probably designed to have no DC bias. Capacitor heating is a concern because its going to be higher for 300 VDC than for 120 VAC. Constant DC means constant leakage, and this results in more internal heat. Add to that the effect of higher voltage, and you could see capacitor failures or premature end of life due to voltage stress. Wilson "Spudley" wrote in message ... "Jimmy" wrote in message m... It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Where do you get your 300 Volt Direct Current (vdc) supply from? That's Direct Current, not Alternating Current (AC) It sure as hell doesn't come out from a wall outlet, as mains supplied power is AC not DC. If it is VDC then it could be applied straight across the large Filter Capacitors. Making sure you have the correct polarity applied. Positive rail to Positive and Negative supply rail applied to Negative, else smoke and fire or bodily damage may result. Sounds like a dangerous project to me. |
#7
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PC power supplies
What I have found so far is very incouraging. In the 120VAC mode the
rectifiers in the front end are working in a voltage doubler configuration which would prohibit what I am trying to do. However in the 240 VAC mode they work as a more conventional powersupply rectifying the 240 and allowing it to come to the peak of the AC which is 300VDC. Still havent got this all traced out yet, but think the rectifier configuration for 240VAC use is a bridge. If so, the polarity of the input should not matter. "Wilson" wrote in message s.com... I agree with Spudley - its a dangerous thing to do. You are correct that most offline switchers have this type of direct rectifier front end. While this might work with a particular supply, you can't make assumptions about it without detailed info on the supply you are using. Additionally, what happens if the supply fails and someone replaces it with a different type or model? There are no guarantees on internal polarity, or current ratings of the various input devices. You should look carefully at the DC ratings of the input line filter components, (both coils and caps). I bet the "Y" capacitors on the input lines are going to have a tough time with 300 VDC. They are probably designed to have no DC bias. Capacitor heating is a concern because its going to be higher for 300 VDC than for 120 VAC. Constant DC means constant leakage, and this results in more internal heat. Add to that the effect of higher voltage, and you could see capacitor failures or premature end of life due to voltage stress. Wilson "Spudley" wrote in message ... "Jimmy" wrote in message m... It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Where do you get your 300 Volt Direct Current (vdc) supply from? That's Direct Current, not Alternating Current (AC) It sure as hell doesn't come out from a wall outlet, as mains supplied power is AC not DC. If it is VDC then it could be applied straight across the large Filter Capacitors. Making sure you have the correct polarity applied. Positive rail to Positive and Negative supply rail applied to Negative, else smoke and fire or bodily damage may result. Sounds like a dangerous project to me. |
#8
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PC power supplies
"Rein Wiehler" wrote in message able.rogers.com... Jimmy wrote: It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Warning! what are you trying to dO? send smoke signals? Who was telling you about 300vdc? to power up a PC? A pc uses +5Vdc and +12VDc. so forget about your idea. Thats funny mine says it will plug into 120 or 240 VAC. I never saw one that plugged in 5 volts before. Must be getting close to sucess when people start telling me it is impossible. |
#9
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PC power supplies
On Tue, 21 Oct 2003 20:00:20 +0000, Jimmy wrote:
A pc uses +5Vdc and +12VDc. so forget about your idea. Thats funny mine says it will plug into 120 or 240 VAC. I never saw one that plugged in 5 volts before. Must be getting close to sucess when people start telling me it is impossible. The Motherboard uses something like 12VDC, other components use 5VDC. The Power Supply plugs into 120VAC or 240VAC. -- Lenroc |
#10
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PC power supplies
Poked around inside the powersupply and found an eletrolytic cap with guess
what voltage on it, 300vdc. disconnected power supply from the line and connected my 300vdc source across the cap. Works like a charm so far. All normal outputs are present.Still need to find more about how the rectifiers are configured before I am willing to run 300vdc in through the line Nay sayers always bring me luck. Thanks lots guys. "Jimmy" wrote in message news "Rein Wiehler" wrote in message able.rogers.com... Jimmy wrote: It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Warning! what are you trying to dO? send smoke signals? Who was telling you about 300vdc? to power up a PC? A pc uses +5Vdc and +12VDc. so forget about your idea. Thats funny mine says it will plug into 120 or 240 VAC. I never saw one that plugged in 5 volts before. Must be getting close to sucess when people start telling me it is impossible. |
#11
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PC power supplies
"Jimmy" wrote in message m... What I have found so far is very incouraging. In the 120VAC mode the rectifiers in the front end are working in a voltage doubler configuration which would prohibit what I am trying to do. However in the 240 VAC mode they work as a more conventional powersupply rectifying the 240 and allowing it to come to the peak of the AC which is 300VDC. Still havent got this all traced out yet, but think the rectifier configuration for 240VAC use is a bridge. If so, the polarity of the input should not matter. It does not matter then, that's if you are applying your 300VDC prior to the bridge rectifier "AC INPUTS" ~ ~ , as the bridge will provide the correct polarity to the filter capacitors for you. None the less, it is a rather dangerous exercise. ps I'm still curious as to where you obtain your 300VDC from, it must be coming from another power supply, which seems kind of pointless to me, if that is the case. "Wilson" wrote in message s.com... I agree with Spudley - its a dangerous thing to do. You are correct that most offline switchers have this type of direct rectifier front end. While this might work with a particular supply, you can't make assumptions about it without detailed info on the supply you are using. Additionally, what happens if the supply fails and someone replaces it with a different type or model? There are no guarantees on internal polarity, or current ratings of the various input devices. You should look carefully at the DC ratings of the input line filter components, (both coils and caps). I bet the "Y" capacitors on the input lines are going to have a tough time with 300 VDC. They are probably designed to have no DC bias. Capacitor heating is a concern because its going to be higher for 300 VDC than for 120 VAC. Constant DC means constant leakage, and this results in more internal heat. Add to that the effect of higher voltage, and you could see capacitor failures or premature end of life due to voltage stress. Wilson "Spudley" wrote in message ... "Jimmy" wrote in message m... It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Where do you get your 300 Volt Direct Current (vdc) supply from? That's Direct Current, not Alternating Current (AC) It sure as hell doesn't come out from a wall outlet, as mains supplied power is AC not DC. If it is VDC then it could be applied straight across the large Filter Capacitors. Making sure you have the correct polarity applied. Positive rail to Positive and Negative supply rail applied to Negative, else smoke and fire or bodily damage may result. Sounds like a dangerous project to me. |
#12
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PC power supplies
Spudley:
Please consider installing and using OE-QuoteFix (http://flash.to/oe-quotefix). If you will look over your last post, you will see that where you quoted about 3 or 4 levels of quoted text, at the end of long lines, the number of ''s does not match the level of quoted text. So, when you are quoting "Jimmy", anything written by him should have " " in front of it, but in some places you end up with only " ", making it very hard to follow what you are saying. Just installing OE-QuoteFix will fix this problem automatically, as well as making news posts much easier to read for you. This is not even mentioning the problem that you apparently quoted an entire message, and put your new material in the middle, with nothing added at either the top or the bottom. (In other words, you could stand to learn how to snip too...) In this case, I am quoting your entire message so you can see how it looks Note: instead of installing OE-QuoteFix, you could instead just get a better newsreader, but I'm not very likely to talk you into that On Thu, 23 Oct 2003 15:31:23 +0000, Spudley wrote: Subject: PC power supplies From: "Spudley" Newsgroups: alt.electronics X-Newsreader: Microsoft Outlook Express 6.00.2800.1158 Date: Thu, 23 Oct 2003 15:31:23 GMT "Jimmy" wrote in message m... What I have found so far is very incouraging. In the 120VAC mode the rectifiers in the front end are working in a voltage doubler configuration which would prohibit what I am trying to do. However in the 240 VAC mode they work as a more conventional powersupply rectifying the 240 and allowing it to come to the peak of the AC which is 300VDC. Still havent got this all traced out yet, but think the rectifier configuration for 240VAC use is a bridge. If so, the polarity of the input should not matter. It does not matter then, that's if you are applying your 300VDC prior to the bridge rectifier "AC INPUTS" ~ ~ , as the bridge will provide the correct polarity to the filter capacitors for you. None the less, it is a rather dangerous exercise. ps I'm still curious as to where you obtain your 300VDC from, it must be coming from another power supply, which seems kind of pointless to me, if that is the case. "Wilson" wrote in message s.com... I agree with Spudley - its a dangerous thing to do. You are correct that most offline switchers have this type of direct rectifier front end. While this might work with a particular supply, you can't make assumptions about it without detailed info on the supply you are using. Additionally, what happens if the supply fails and someone replaces it with a different type or model? There are no guarantees on internal polarity, or current ratings of the various input devices. You should look carefully at the DC ratings of the input line filter components, (both coils and caps). I bet the "Y" capacitors on the input lines are going to have a tough time with 300 VDC. They are probably designed to have no DC bias. Capacitor heating is a concern because its going to be higher for 300 VDC than for 120 VAC. Constant DC means constant leakage, and this results in more internal heat. Add to that the effect of higher voltage, and you could see capacitor failures or premature end of life due to voltage stress. Wilson "Spudley" wrote in message ... "Jimmy" wrote in message m... It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Where do you get your 300 Volt Direct Current (vdc) supply from? That's Direct Current, not Alternating Current (AC) It sure as hell doesn't come out from a wall outlet, as mains supplied power is AC not DC. If it is VDC then it could be applied straight across the large Filter Capacitors. Making sure you have the correct polarity applied. Positive rail to Positive and Negative supply rail applied to Negative, else smoke and fire or bodily damage may result. Sounds like a dangerous project to me. |
#13
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PC power supplies
I have just installed OE-QuoteFix, here's hoping that it fixes the
problems you are referring to. Thanks Lenroc for the pointers. Lenroc wrote: Spudley: Please consider installing and using OE-QuoteFix (http://flash.to/oe-quotefix). If you will look over your last post, you will see that where you quoted about 3 or 4 levels of quoted text, at the end of long lines, the number of ''s does not match the level of quoted text. So, when you are quoting "Jimmy", anything written by him should have " " in front of it, but in some places you end up with only " ", making it very hard to follow what you are saying. Just installing OE-QuoteFix will fix this problem automatically, as well as making news posts much easier to read for you. This is not even mentioning the problem that you apparently quoted an entire message, and put your new material in the middle, with nothing added at either the top or the bottom. (In other words, you could stand to learn how to snip too...) In this case, I am quoting your entire message so you can see how it looks Note: instead of installing OE-QuoteFix, you could instead just get a better newsreader, but I'm not very likely to talk you into that On Thu, 23 Oct 2003 15:31:23 +0000, Spudley wrote: Subject: PC power supplies From: "Spudley" Newsgroups: alt.electronics X-Newsreader: Microsoft Outlook Express 6.00.2800.1158 Date: Thu, 23 Oct 2003 15:31:23 GMT "Jimmy" wrote in message m... What I have found so far is very incouraging. In the 120VAC mode the rectifiers in the front end are working in a voltage doubler configuration which would prohibit what I am trying to do. However in the 240 VAC mode they work as a more conventional powersupply rectifying the 240 and allowing it to come to the peak of the AC which is 300VDC. Still havent got this all traced out yet, but think the rectifier configuration for 240VAC use is a bridge. If so, the polarity of the input should not matter. I am including the whole of the message in an effort to see how effective OE-QuoteFix really is. It does not matter then, that's if you are applying your 300VDC prior to the bridge rectifier "AC INPUTS" ~ ~ , as the bridge will provide the correct polarity to the filter capacitors for you. None the less, it is a rather dangerous exercise. ps I'm still curious as to where you obtain your 300VDC from, it must be coming from another power supply, which seems kind of pointless to me, if that is the case. "Wilson" wrote in message s.com... I agree with Spudley - its a dangerous thing to do. You are correct that most offline switchers have this type of direct rectifier front end. While this might work with a particular supply, you can't make assumptions about it without detailed info on the supply you are using. Additionally, what happens if the supply fails and someone replaces it with a different type or model? There are no guarantees on internal polarity, or current ratings of the various input devices. You should look carefully at the DC ratings of the input line filter components, (both coils and caps). I bet the "Y" capacitors on the input lines are going to have a tough time with 300 VDC. They are probably designed to have no DC bias. Capacitor heating is a concern because its going to be higher for 300 VDC than for 120 VAC. Constant DC means constant leakage, and this results in more internal heat. Add to that the effect of higher voltage, and you could see capacitor failures or premature end of life due to voltage stress. Wilson "Spudley" wrote in message ... "Jimmy" wrote in message m... It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Where do you get your 300 Volt Direct Current (vdc) supply from? That's Direct Current, not Alternating Current (AC) It sure as hell doesn't come out from a wall outlet, as mains supplied power is AC not DC. If it is VDC then it could be applied straight across the large Filter Capacitors. Making sure you have the correct polarity applied. Positive rail to Positive and Negative supply rail applied to Negative, else smoke and fire or bodily damage may result. Sounds like a dangerous project to me. |
#14
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PC power supplies
"Spudley" wrote in message ... "Jimmy" wrote in message m... What I have found so far is very incouraging. In the 120VAC mode the rectifiers in the front end are working in a voltage doubler configuration which would prohibit what I am trying to do. However in the 240 VAC mode they work as a more conventional powersupply rectifying the 240 and allowing it to come to the peak of the AC which is 300VDC. Still havent got this all traced out yet, but think the rectifier configuration for 240VAC use is a bridge. If so, the polarity of the input should not matter. It does not matter then, that's if you are applying your 300VDC prior to the bridge rectifier "AC INPUTS" ~ ~ , as the bridge will provide the correct polarity to the filter capacitors for you. None the less, it is a rather dangerous exercise. ps I'm still curious as to where you obtain your 300VDC from, it must be coming from another power supply, which seems kind of pointless to me, if that is the case. ************** 300 vdc powers supply works off of 24 vdc input. Origonaly unit was designed to feed up to 4 DC to DC converters that gave +- 5 and +-15vdc output. I am going to use it in my diesel school bus turned RV to power a PC which will be the heart of a navigation/ entertainment center. "Wilson" wrote in message s.com... I agree with Spudley - its a dangerous thing to do. You are correct that most offline switchers have this type of direct rectifier front end. While this might work with a particular supply, you can't make assumptions about it without detailed info on the supply you are using. Additionally, what happens if the supply fails and someone replaces it with a different type or model? There are no guarantees on internal polarity, or current ratings of the various input devices. You should look carefully at the DC ratings of the input line filter components, (both coils and caps). I bet the "Y" capacitors on the input lines are going to have a tough time with 300 VDC. They are probably designed to have no DC bias. Capacitor heating is a concern because its going to be higher for 300 VDC than for 120 VAC. Constant DC means constant leakage, and this results in more internal heat. Add to that the effect of higher voltage, and you could see capacitor failures or premature end of life due to voltage stress. Wilson "Spudley" wrote in message ... "Jimmy" wrote in message m... It is my understanding that PC powersupplies take 120 AC and run it through a voltage doubler rectifying it and giving 300vdc. What I want to do is feed 300vdc into the powersupply via the line cord with no modification to the power supply. As I dont have a schematic could someone please tell me if this would work Where do you get your 300 Volt Direct Current (vdc) supply from? That's Direct Current, not Alternating Current (AC) It sure as hell doesn't come out from a wall outlet, as mains supplied power is AC not DC. If it is VDC then it could be applied straight across the large Filter Capacitors. Making sure you have the correct polarity applied. Positive rail to Positive and Negative supply rail applied to Negative, else smoke and fire or bodily damage may result. Sounds like a dangerous project to me. |
#15
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PC power supplies
snip
ps I'm still curious as to where you obtain your 300VDC from, it must be coming from another power supply, which seems kind of pointless to me, if that is the case. ************** 300 vdc powers supply works off of 24 vdc input. Origonaly unit was designed to feed up to 4 DC to DC converters that gave +- 5 and +-15vdc output. I am going to use it in my diesel school bus turned RV to power a PC which will be the heart of a navigation/ entertainment center. Sounds like a worth while exercise then. Good luck and I hope you don't damage something doing it, especially yourself. snip |
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