Modding a Hewlett Packard 750 Watt Power Supply
08-27-2016, 07:45 PM
#16
I learned the hard way to never hook up the battery, or the charger, before plugging the power supply in, good by Reaktor 300 charger, ouch. What painful(expensive) lessons we learn.
08-28-2016, 08:23 PM
#17
08-30-2016, 05:57 PM
#18
They are around 62.5 amps now, the HP 750 watt. This is what I now use as I finally got it modded. I also picked up a Junsi 206B charger, what a system. The HP 750 has enough amps for two of these chargers. If I get a parallel board, I could charge two batteries at once with this charger. I plan on charging all my batteries at 1.5c.
08-31-2016, 06:26 PM
#19
I haven't seen any dual HP power supplies in that price range with the work already done, no way. I want to see your cards on this! Stubbs, where did you get the heat shrink tubing, and did you isolate the one unit's ground? and how? I also want to know how you hooked up the power from one unit to the other? in series?
- What heat shrink tubing are you referring to?
- You isolate the ground on one unit by drilling out the metal nuts that the PCB is screwed into, and replacing them with plastic ones. This makes that particular PS a "floating ground". The RChelination article goes over that in detail.
- Yes, hook them up in series.....negative from PS1 goes to positive of PS2. If you put extra bullets on each unit, you can connect up a set of 12V wires, as well as a set of 24V.
Why did you buy resistors from China? I went to my local Radio Shack, and picked up a 5 pack for $1.49......
09-03-2016, 07:07 PM
#20
Radio shack went out of business in this area a long time ago. The shrink wrap is used to wrap two power supplies together.
09-03-2016, 08:52 PM
#21
Sorry, I haven't been on the forum very much over the past couple of weeks, and didn't see your questions.
- What heat shrink tubing are you referring to?
- You isolate the ground on one unit by drilling out the metal nuts that the PCB is screwed into, and replacing them with plastic ones. This makes that particular PS a "floating ground". The RChelination article goes over that in detail.
- Yes, hook them up in series.....negative from PS1 goes to positive of PS2. If you put extra bullets on each unit, you can connect up a set of 12V wires, as well as a set of 24V.
Why did you buy resistors from China? I went to my local Radio Shack, and picked up a 5 pack for $1.49......
- What heat shrink tubing are you referring to?
- You isolate the ground on one unit by drilling out the metal nuts that the PCB is screwed into, and replacing them with plastic ones. This makes that particular PS a "floating ground". The RChelination article goes over that in detail.
- Yes, hook them up in series.....negative from PS1 goes to positive of PS2. If you put extra bullets on each unit, you can connect up a set of 12V wires, as well as a set of 24V.
Why did you buy resistors from China? I went to my local Radio Shack, and picked up a 5 pack for $1.49......
09-05-2016, 06:32 PM
#22
Thanks. I am still debating whether I really need such a powerhouse just yet. The HP 750 by itself is no light weight. I just find it so hard to believe how cheap these are. Does anyone have a source for the dual plugs to run two of them?
09-05-2016, 07:50 PM
#23
I found this one on newegg.com and Amazon, but you can just google "computer power y-cable"
http://www.newegg.com/Product/Produc...82E16812200045
https://www.amazon.com/StarTech-com-.../dp/B0002GRQR2
09-08-2016, 05:31 PM
#24
Yeah, the second one is it. Thanks! That will make a duo easier to plug in.
10-15-2016, 01:21 PM
#26
The power supply usually doesn't have one, it will be on the charger, as my Junsi 206B has one. I now run two chargers off this power supply, the HK Reaktor 250 watt @ 10 amps, and the Junsi 206B @ 20 amps. They both work excellent, and are highly recommended. I spent $25 on the power supply, and $165 on the chargers, what a bargain. I use the Reaktor on 2s, and the Junsi on 3 and 4s batteries. I charge 2s@ 9 amps, and 3/4s @ 12 amps. Batteries are ready very quickly.
10-16-2016, 08:33 AM
#27
Please elaborate. I've hooked up my Reaktor 300 charger to the power supply before plugging it in and have never hurt it. (I have a modified server power supply) However, I do not have a battery hooked up to the charger at the time. Why will this hurt the charger?
10-16-2016, 11:50 AM
#28
There is a warning to never have the battery hooked up before turning on the power supply. If you look at their ad for the charger it is at the bottom. I heard that some power supplies like the modded computer types spike when plugged in. I never had this problem with the other power supply I use,the HP 600 DPS. The DPS is a better power supply, but rather large, and the HP 750 is amazingly small for the power it has.
10-16-2016, 12:25 PM
#29
10-17-2016, 12:43 PM
#30
Tech Adept
I've been doing this for years. I just cannibalize them from old servers so it's all free for me. The only thing I haven't figured out is how to run them in series. Everyone keeps talking about removing the ground from PS2 but never actually explains how to do it. Someone said to isolate the PCB on nylon nuts but that doesn't make any sense because you are using metal screws that will still ground. Others have said to disconnect the A/C ground but again, doesn't make any sense because in older houses the ground and neutral wires are tied together at the circuit breaker.