turning pc power supply into a rc power supply
01-16-2006, 12:23 PM
#16
Tech Addict
Some chargers (at least the Tekin 112 and I think Duratrax ICE) can charge with higher output than input voltage. Some circuitry inside the charger raises the voltage internally. For the Tekin, 11 volt input voltage is enough to charge all standard packs, transmitter packs too.
01-16-2006, 01:44 PM
#17
Originally Posted by bender
Because there are so many of the yellow (+12v), red (+5v), and black (common) wires, you can solder 2 or 3 together to the output jacks and then you'll have no problems 
01-16-2006, 03:38 PM
#18
Originally Posted by bender
There is a label on most (if not all) power supplies that tells you the maximum amps for each voltage (3.3, 5.0, 12v).
Most 400-500w PSU usually have a rating of 17 amps or more on the 12v line - which is enough to run 2 chargers without problems.
Just a few notes for those intending to build one:
Firstly, there are several links around to show you how to build one, with the main difference being whether or not to use a load device (resistor or light globe) on the 5v line.
Generally, the 5v line WILL need some load for the PSU to provide enough voltage on the 12v line - how much load really depends upon the quality and wattage of the PSU you have. As an example, I've seen instructions call for the use of a 10ohm resistor, yet my unit runs a 2ohm resistor to provide the necessary load. Some PSU's do not require ANY resistors to work correctly - so there is no real "right way" to do it.
Finally, remember that these PSU's are really not designed for us to open them up and start mucking around inside - so be CAREFUL!
It is possible to make one work properly without opening the case (though it looks untidy) - but if you are going to wire everything up internally then make sure the PSU has been unplugged for a long time - as there as several large capacitors inside that are still capable of giving you a nasty shock.
It's best to completely finish the unit before switching on for the first time.
EDIT:
I have seen a lot of threads on the net turn into nasty arguments over the safety issues with building these PSU's so do not attempt this if you are not 100% sure of what you're doing.
Most 400-500w PSU usually have a rating of 17 amps or more on the 12v line - which is enough to run 2 chargers without problems.
Just a few notes for those intending to build one:
Firstly, there are several links around to show you how to build one, with the main difference being whether or not to use a load device (resistor or light globe) on the 5v line.
Generally, the 5v line WILL need some load for the PSU to provide enough voltage on the 12v line - how much load really depends upon the quality and wattage of the PSU you have. As an example, I've seen instructions call for the use of a 10ohm resistor, yet my unit runs a 2ohm resistor to provide the necessary load. Some PSU's do not require ANY resistors to work correctly - so there is no real "right way" to do it.
Finally, remember that these PSU's are really not designed for us to open them up and start mucking around inside - so be CAREFUL!
It is possible to make one work properly without opening the case (though it looks untidy) - but if you are going to wire everything up internally then make sure the PSU has been unplugged for a long time - as there as several large capacitors inside that are still capable of giving you a nasty shock.
It's best to completely finish the unit before switching on for the first time.
EDIT:
I have seen a lot of threads on the net turn into nasty arguments over the safety issues with building these PSU's so do not attempt this if you are not 100% sure of what you're doing.
Thanks
01-16-2006, 03:58 PM
#19
Originally Posted by ATLAS COPCO
Please tell me what wattage is the 2ohm resistor that you use
Thanks
Thanks
I use a 25w resistor (as shown in an earlier post) though you could use a 100w if you wanted - the higher the wattage the better the resistor will handle the heat.
Most instructions call for a minimum 10 watt Ceramic resistor - IMO they get too hot, that's why I recommend the heatsink type.
01-16-2006, 04:05 PM
#20
Originally Posted by nikkiesteban
oh.. but do u think that it can't over the voltage of that???
As I mentioned, The overall voltage of the 12v line depends upon the load placed on the +5v line, the more load you apply to the +5v line, the higher the voltage on the +12v line.
To handle the current of supplying power to a charger running at 6amps, it's best to have 2 or 3 yellow wires going to one output plug, the same with the red and black wires. There are heaps of each type of wire on the PSU so you won't run out.
01-16-2006, 04:20 PM
#21
Hey Guys.
I converted a brand new OCZ 450W ModStream PSU and It delivers about 30 amps...I ran a 10 amp motor cooler, PitbullX3 at 7 amps, Much More cell master at 7.5 amps and a pitbull at 6 amps all at once and that was its limit. So you know your good.
With a newer kind of PSU you have to connect the green and ground wires on the 20-24 pin mobo connector. Once you do this it will turn on. Then I only had about 11 volts. I put 3 10ohm 10watt resistors and got 12.4 volts, and I added 3 15 ohm 20 watt resistors to the 10 ohm 10watt ones and Im pushing 13.5 or so now. I also cut all the connectors off that went to the mobo and stuff.
This PSU I made is for higher power consumption I guess.
The OCZ powersupplies not only look good, but there SUPER DOOPER quiet and have LOTS of cooling for your Resistors. Mine arent even warm. I bought a much more worlds before this one and I cooked one, and cooked my 2nd thrusday before friday race night. I went out, got this and converted it in about 3 hours. The BEST thing about this PSU is it has the molex adaptors at the front, I have fans and stuff hooked up to molex's and I can plug/unplug at my own preference.
http://www.memoryexpress.com/index.p...ctID=5378&SID=
Thats the PSU I used, Thats Canadian dollars.
Its got all the good stuff, short protection, heat shutdown etc. It kicks arse.
If you guys want I can take pics and post them....Its a real good power supply.
I converted a brand new OCZ 450W ModStream PSU and It delivers about 30 amps...I ran a 10 amp motor cooler, PitbullX3 at 7 amps, Much More cell master at 7.5 amps and a pitbull at 6 amps all at once and that was its limit. So you know your good.
With a newer kind of PSU you have to connect the green and ground wires on the 20-24 pin mobo connector. Once you do this it will turn on. Then I only had about 11 volts. I put 3 10ohm 10watt resistors and got 12.4 volts, and I added 3 15 ohm 20 watt resistors to the 10 ohm 10watt ones and Im pushing 13.5 or so now. I also cut all the connectors off that went to the mobo and stuff.
This PSU I made is for higher power consumption I guess.
The OCZ powersupplies not only look good, but there SUPER DOOPER quiet and have LOTS of cooling for your Resistors. Mine arent even warm. I bought a much more worlds before this one and I cooked one, and cooked my 2nd thrusday before friday race night. I went out, got this and converted it in about 3 hours. The BEST thing about this PSU is it has the molex adaptors at the front, I have fans and stuff hooked up to molex's and I can plug/unplug at my own preference.
http://www.memoryexpress.com/index.p...ctID=5378&SID=
Thats the PSU I used, Thats Canadian dollars.
Its got all the good stuff, short protection, heat shutdown etc. It kicks arse.
If you guys want I can take pics and post them....Its a real good power supply.
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