Hello all,
I've got myself a spare TFT monitor, but I don't have a powersupply for it. My son keeps getting headaches off using a CRT, and he got so excited, he asked if I could power it from something else. Ive assembled a lead with a ferrite tube from an old monitor lead at the TFT end and the other end a ferrite ring and attached that end to the Yellow and Black of an IDE socket, thats not supplying any drives. I've told him to allow time between turning the PC on and then switching the monitor on. I turned it on after POST beep and it began to flicker when the Harddrive kicked in. After allowing for the surge then switching on, the display is fine. The backlights are okay, but there seems to be lines running up the screen on dark colours. I tried changing refresh from 60hz to 75hz and it flickered erraticaly. I switched back to 60hz and all is well, bar these faint lines.
The Pc's supply isn't getting hot, and he's happily surfing the web. I'm just asking, am I okay doing this, until I can buy a proper supply, and are the lines just noise from the supply? If its okay powering the TFT this way, can the lines be removed with a cap or something?
Cheers iUSERTLO72p🙂
I've got myself a spare TFT monitor, but I don't have a powersupply for it. My son keeps getting headaches off using a CRT, and he got so excited, he asked if I could power it from something else. Ive assembled a lead with a ferrite tube from an old monitor lead at the TFT end and the other end a ferrite ring and attached that end to the Yellow and Black of an IDE socket, thats not supplying any drives. I've told him to allow time between turning the PC on and then switching the monitor on. I turned it on after POST beep and it began to flicker when the Harddrive kicked in. After allowing for the surge then switching on, the display is fine. The backlights are okay, but there seems to be lines running up the screen on dark colours. I tried changing refresh from 60hz to 75hz and it flickered erraticaly. I switched back to 60hz and all is well, bar these faint lines.
The Pc's supply isn't getting hot, and he's happily surfing the web. I'm just asking, am I okay doing this, until I can buy a proper supply, and are the lines just noise from the supply? If its okay powering the TFT this way, can the lines be removed with a cap or something?
Cheers iUSERTLO72p🙂
Buy a cheap noise isolator (the type used with car radios) and insert it in series.
Also try using a thick wire to ground the monitor to the case.
Also try using a thick wire to ground the monitor to the case.
Cheers star882
Thanks for replying, do you mean a capacitor
Thanks again
iUSERTLO72p🙂
Thanks for replying, do you mean a capacitor
, or something else?
Thanks again
iUSERTLO72p🙂
This seems to be a ground loop problem because you are using standard analog VGA video and the power supply ground is not at the same AC potential as the video source.
The simpler solution is a separate isolated power supply. No amount of filtering will break the ground loop down to DC and you will still see video intensity changes when something in the computer starts drawing more or less current.
The simpler solution is a separate isolated power supply. No amount of filtering will break the ground loop down to DC and you will still see video intensity changes when something in the computer starts drawing more or less current.
Thanks Eva
Today, he has a clear display! Got a supply on order.🙂
Can you view my other post, http://www.diyaudio.com/forums/showthread.php?threadid=111667 , please.😀
Cheers iUSERTLO72p🙂
Today, he has a clear display! Got a supply on order.🙂
Can you view my other post, http://www.diyaudio.com/forums/showthread.php?threadid=111667 , please.😀
Cheers iUSERTLO72p🙂
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