- Joined
- Aug 21, 2001
- Location
- Milton Keynes, UK
Boosting 5v by adding regulators
Warning:
I am not responsable for any damage caused by anyone perfoming this mod, do this at your own risk, this should only be attempted by people who are capable of perfoming this easilly and have had some experaince soldering.
If you would still like to perform this mod and ddo not have the skills requires, i recomend purchasing a diy kit such as a small amplifer or radio to help develop your skills, these are quite cheap and should be avalable from stores such as Maplin (in the UK) and Radio Shack (in the US)
Problem:
I have a very old motherbaod in my computer, it is an Abit KT7A, i still use it because i have very good ram that can do 170MHz Cas 3 or, as i usally run it - 160MHz cas2, this motherboard also supports the new Barton core (last time i checked) In addition i have no money, so i canot afford to purchase a motherboard and DDR ram at the same time, or even on their own!
This motherboard was not designed for the newest Processors and Graphics cards, and these draw more power then the motherboad can provide, this causes the 5v line to fluctuate. This is not just for this motherboard and all older motherboards and some new motherboards still have this problem.
The Solutions:
There have beeen a few solutions suggested so far, the most common one being taking a spare 5v cable and attaching it directly to the gate of the 5v regulating MOSFET's to provide additional power, however the motherboard smooths and regulates the 5v line, the 5v that is being given to it has lots of noise which is responsable for crashes.
another idea would be to increase the capacitance of the smoothing capacitors on the motherbard so that more power can be stored - allowing more to be delivered when needed (this is when the 5v line goes down) so the line wouldn not fluctuate as much.
However, i chose a different way.
5v regulators are avalable at every electronic shop such as Maplin (in the UK) and Radio Shack (in the US) they cost very little and are very effective and taking a higher voltage down to 5v.
i chose to regulate 12v down to 5v to deliver to the MOSFET's this is because when the 5v regulator is in the circuit shown below, it is very effective at keeping 5v very clean thus reducing the ammount of crashes and preventing the 5v from fluctuating.
for this purpose C1 should be above 470uf (i used 2200uf) and the voltage rating should be above 12v (common values are 16v and 25v) i used 16v as there is no need for a greater value as i don not think the 12v line it is being provided with will change uch, if it does it will case much more dammage then just a capacitor expoding.
C2 is for additional smoothing and can be a film capacitor or ceramic, i used a 100nf (0.1uf) ceramic but any value between 10nf (0.01uf) and about 1uf is fine.
i took the 12v line off the back of the motherbard where it connects to the motherboard connector, it was then routed to the front though two holes (shown in the picture below)
i then soldered the regulators directly to the pins of the MOSFETs this reduced the resistance so the voltage is closer to 5v, i used one regulator per MOSFET and each regulator had a smoothing capacitor even though the eletrolytic capacitor was shared between them.
please make sure that the electrolytic capacitor is the right way around.. something i supidly overlooked untill i had put the motherboard INSIDE the case.
Warning:
I am not responsable for any damage caused by anyone perfoming this mod, do this at your own risk, this should only be attempted by people who are capable of perfoming this easilly and have had some experaince soldering.
If you would still like to perform this mod and ddo not have the skills requires, i recomend purchasing a diy kit such as a small amplifer or radio to help develop your skills, these are quite cheap and should be avalable from stores such as Maplin (in the UK) and Radio Shack (in the US)
Problem:
I have a very old motherbaod in my computer, it is an Abit KT7A, i still use it because i have very good ram that can do 170MHz Cas 3 or, as i usally run it - 160MHz cas2, this motherboard also supports the new Barton core (last time i checked) In addition i have no money, so i canot afford to purchase a motherboard and DDR ram at the same time, or even on their own!
This motherboard was not designed for the newest Processors and Graphics cards, and these draw more power then the motherboad can provide, this causes the 5v line to fluctuate. This is not just for this motherboard and all older motherboards and some new motherboards still have this problem.
The Solutions:
There have beeen a few solutions suggested so far, the most common one being taking a spare 5v cable and attaching it directly to the gate of the 5v regulating MOSFET's to provide additional power, however the motherboard smooths and regulates the 5v line, the 5v that is being given to it has lots of noise which is responsable for crashes.
another idea would be to increase the capacitance of the smoothing capacitors on the motherbard so that more power can be stored - allowing more to be delivered when needed (this is when the 5v line goes down) so the line wouldn not fluctuate as much.
However, i chose a different way.
5v regulators are avalable at every electronic shop such as Maplin (in the UK) and Radio Shack (in the US) they cost very little and are very effective and taking a higher voltage down to 5v.
i chose to regulate 12v down to 5v to deliver to the MOSFET's this is because when the 5v regulator is in the circuit shown below, it is very effective at keeping 5v very clean thus reducing the ammount of crashes and preventing the 5v from fluctuating.
for this purpose C1 should be above 470uf (i used 2200uf) and the voltage rating should be above 12v (common values are 16v and 25v) i used 16v as there is no need for a greater value as i don not think the 12v line it is being provided with will change uch, if it does it will case much more dammage then just a capacitor expoding.
C2 is for additional smoothing and can be a film capacitor or ceramic, i used a 100nf (0.1uf) ceramic but any value between 10nf (0.01uf) and about 1uf is fine.
i took the 12v line off the back of the motherbard where it connects to the motherboard connector, it was then routed to the front though two holes (shown in the picture below)
i then soldered the regulators directly to the pins of the MOSFETs this reduced the resistance so the voltage is closer to 5v, i used one regulator per MOSFET and each regulator had a smoothing capacitor even though the eletrolytic capacitor was shared between them.
please make sure that the electrolytic capacitor is the right way around.. something i supidly overlooked untill i had put the motherboard INSIDE the case.