PSU PC what voltages?

Started by Dirk Bruere at NeoPax in sci.electronics.design6 years ago 14 replies
PSU

When the PC is "switched off" by the button connected to the mobo the PSU goes into a quiescent state, yet must supply voltage to the...

When the PC is "switched off" by the button connected to the mobo the PSU goes into a quiescent state, yet must supply voltage to the mobo. What voltages are active on the PSU, and what only comes up when the mobo powers up? -- Dirk http://www.neopax.com/technomage/ - Magick and Technology


PC PSU driving relay

Started by Dirk Bruere at NeoPax in sci.electronics.design5 years ago 9 replies

I am using the +12VDC from a PC PSU to switch mains using a relay ie when the PC turns on mains power gets supplied to some amplifiers. Do I...

I am using the +12VDC from a PC PSU to switch mains using a relay ie when the PC turns on mains power gets supplied to some amplifiers. Do I need diode protection across the relay coil for when the PC PSU switches off, or do such PSUs have such protection built in? -- Dirk Full Spectrum Praxis : ZERO STATE : http://zerostate.net


9v UNregulated PSU

Started by phaedrus in sci.electronics.design8 years ago 13 replies
PSU

Hi, chums, It's good for you for me to be back! Anyone know of a really simple 9v limited PSU schematic with no regulation and no filtering...

Hi, chums, It's good for you for me to be back! Anyone know of a really simple 9v limited PSU schematic with no regulation and no filtering or owt.?


High Energy Testing

Started by David L. Jones in sci.electronics.design9 years ago 9 replies
PSU

A frind of mine recently had fun testing a custom high energy PSU, too cool not to pass on: "This photo was taken during routine testing of...

A frind of mine recently had fun testing a custom high energy PSU, too cool not to pass on: "This photo was taken during routine testing of my 400 joule discharge PSU. The PSU dumps 4,500V pulses to the load, at a rate of three 400j jolts per second. The load resistor is a 10-ohm, 450-watt beastie which gets damn hot during testing - more than 200degC, despite the fan. The load r...


WANTED, THE UNIVERSAL INPUT PSU

Started by Anonymous in sci.electronics.design8 years ago 2 replies
PSU

Looking for 110-265V 50/60/400 HZ and 12-28V DC INPUT 48V output psu for a military application. I doubt it exists, load is 3...

Looking for 110-265V 50/60/400 HZ and 12-28V DC INPUT 48V output psu for a military application. I doubt it exists, load is 3 amps. Steve


HV PSU - why isolate

Started by NT in sci.electronics.design6 years ago 15 replies

I'm assembling a 680v psu delivering upto 85 microamps max. This current is limited on both poles by a string of resistors rated to 1kV. Given...

I'm assembling a 680v psu delivering upto 85 microamps max. This current is limited on both poles by a string of resistors rated to 1kV. Given all this I dont see any reason to use an isolating transformer, is that fair enough? Its for lab use, not public sale. NT


PSU for precision audio opamps

Started by Dirk Bruere at NeoPax in sci.electronics.design9 years ago 55 replies

I need +/- 12V from a 5V or 12V supply (PC PSU) to drive precision audio stuff (LM4562). Thinking of using a DC-DC converter eg XP Power or...

I need +/- 12V from a 5V or 12V supply (PC PSU) to drive precision audio stuff (LM4562). Thinking of using a DC-DC converter eg XP Power or C&D. The regulation on these isn't brillant at around 10%, but that shouldn't be a problem. Ripple is typically 0.5% Any advice? Dirk


Earthed PSU question

Started by Anonymous in sci.electronics.design8 years ago 1 reply
PSU

I`ve been struggling with this for quite some time and hope someone may be able to point out the pros and cons: Imaging a situation where I`m...

I`ve been struggling with this for quite some time and hope someone may be able to point out the pros and cons: Imaging a situation where I`m designing a new product and I need to select an external AC=E0DC switch mode PSU with a very standard barrel connection output. The product is a metal case, with chassis connected to system wide 0v. Examples below: http://www.powerconversion.com/p...


New Improved +/-45V PSU

Started by Harry D in sci.electronics.design4 years ago 37 replies

Here is my 2W +/-45V PSU http://kvisit.com/S_KuKAw See the MSD7342-224ml for coupled inductor. The IRF9640 is overkill but only SC3...

Here is my 2W +/-45V PSU http://kvisit.com/S_KuKAw See the MSD7342-224ml for coupled inductor. The IRF9640 is overkill but only SC3 model available. The control loop should be pretty straight forward. What is the input voltage range desired? I would copy in that neat net + wiring list that you guys use but do not know how. Just learning LTSPICE. Cheers, Harry


Recognise this trace?

Started by Cursitor Doom in sci.electronics.design2 months ago 32 replies

Gentlemen, The link below shows a scope trace of the output of a linear PSU (voltage 4.7VDC) with about 300mV of 100Hz ripple riding on it....

Gentlemen, The link below shows a scope trace of the output of a linear PSU (voltage 4.7VDC) with about 300mV of 100Hz ripple riding on it. This PSU is in- circuit under load from the boards it supplies. Normally I would assume a filter capacitor to be at fault here, but they all check out fine so something else is causing this ripple. Note there is a characteristic 'knee' on the high ...


Help with placement of filter inductor

Started by pawihte in sci.electronics.design8 years ago 9 replies
PSU

I want to modify an ATX PSU for use with a project and am thinking of using a classic full-wave voltage doubler to get about -20V from the...

I want to modify an ATX PSU for use with a project and am thinking of using a classic full-wave voltage doubler to get about -20V from the center-tapped 5V winding (I'll be using a PSU with separate 5V and 12V windings and the 12V winding will be used for another section of the project). The rectified output will be further regulated with a linear series regulator, and the load will b...


Power Conversion Electronics

Started by pg in sci.electronics.design8 years ago 32 replies
PSU

I just purchase a Silverstone Power Supply Unit (PSU) for my PC. I am amaze with the PFC (Power Factor Correction) rating of over 0.96, which,...

I just purchase a Silverstone Power Supply Unit (PSU) for my PC. I am amaze with the PFC (Power Factor Correction) rating of over 0.96, which, according to some indicators, means it's 96% efficient. (4% wastage as heat). Since it's a new unit I dare not to open up the PSU to see what type of electronics they are using. So I post the question here ---- Can anyone tell me what type of...


Question For The Gurus - Fan Noise (whine)

Started by Tim in sci.electronics.design9 years ago 53 replies
PSU

OK, I have a computer PSU powering a 100w amp. The system works great, but if I connect the cooling fans (2 x 12v DC brushless), I get a loud...

OK, I have a computer PSU powering a 100w amp. The system works great, but if I connect the cooling fans (2 x 12v DC brushless), I get a loud whine in both channels. What is the best solution to reduce or eliminate the whining? I am limited for space, but could easily add caps or coils to do the job. I cannot put another psu in to run the fans, not enough space for that. All usefu...


Question about AT91SAM7A3 and JTAG

Started by gm in sci.electronics.design7 years ago

Hi I have soldered an AT91SAM7A3 on an TQFP100 adaptor in order to use it with a breadboard. I have connected the following: All the VDD3V3 to...

Hi I have soldered an AT91SAM7A3 on an TQFP100 adaptor in order to use it with a breadboard. I have connected the following: All the VDD3V3 to the PSU 3.3V All the GND to the PSU GND All the JTAG pins to the pins of my ULINK compatible programmer with pull-ups for the TRST, TDI, TMS, TCK and SRST connected to NRST of the uC and JTAGSEL of uC to 3.3V, all the JTAG connector grounds connec...


PSU for TekProbe interface

Started by Klaus Kragelund in sci.electronics.design6 years ago 2 replies
PSU

Hi I got a Tek P5205 HV differential probe, but sadly no longer a scope that can interface to the active probe. So, the specification for...

Hi I got a Tek P5205 HV differential probe, but sadly no longer a scope that can interface to the active probe. So, the specification for the Tektronix TekProbe interface defines the need for +5V, +15V, -15V and -5V. Well that I can handle without bying an expensive Tek PSU So, the question is, if I supply those voltages will the probe work, with connecting the data and offset signals...


Active PFC and square wave supply

Started by Pimpom in sci.electronics.design4 years ago 19 replies

I started using a Tagan 700BZ PSU in my computer a couple of months ago - my first PSU with active PFC. The UPS is a basic one that has served...

I started using a Tagan 700BZ PSU in my computer a couple of months ago - my first PSU with active PFC. The UPS is a basic one that has served me well for 10 years, and outputs a square wave on battery. While setting up this particular combination, I briefly wondered how the PFC circuit would react to working with non-sinusoidal power but then forgot about it - until it died a couple of ...


any pspice/other atx psu models ?

Started by KORISNIK in sci.electronics.design7 years ago

available free someplace thanks in advance

available free someplace thanks in advance


Bipolar transistors in reverse

Started by E in sci.electronics.design8 years ago 12 replies
PSU

Got just two nice lab psu (100W and weight only 13 kg) off Ebay. So to put them in some use I measured how well some bipolars work with...

Got just two nice lab psu (100W and weight only 13 kg) off Ebay. So to put them in some use I measured how well some bipolars work with collector and emitter swapped. http://koti.mbnet.fi/hsahko/trans/ -ek


Trying to source a connector.

Started by Anonymous in sci.electronics.design9 years ago 6 replies

Anybody have any idea what the red and black jacks are on the back of one of these? It used to be a industry standard, but I cant find out...

Anybody have any idea what the red and black jacks are on the back of one of these? It used to be a industry standard, but I cant find out what it is called. sockets on the back of the "phase modulated power supply" here: http://www.uslasercorp.com/catalog/electronics.html I'm switching a laser to a different PSU , and the client wants "no changes" what so ever to the exist...


Odd thing

Started by Anonymous in sci.electronics.design1 year ago 6 replies
PSU

http://www.ebay.co.uk/itm/NV-UHL4-Electric-Device-42v-Soviet-Student-of-the-USSR-Vintage-Rare-19 88-Russia/111302224559 What is it? It looks a...

http://www.ebay.co.uk/itm/NV-UHL4-Electric-Device-42v-Soviet-Student-of-the-USSR-Vintage-Rare-19 88-Russia/111302224559 What is it? It looks a little like a wallwart psu. But I'm far from convinced. I vaguely recall 42v being used rather than 220v in some places, but don't remember any details. NT