I bought a Meanwell RSP-750-15

[SternWake]

Glad to be able to help.

 

[Mobilesport]

Sternwake wrote 
[font=Verdana, Arial, sans-serif]"For the average joe, it is  NOT simple to remove the original voltage trim pot, and solder wires to the circuit board to  run them to the new potentiometer which also needs to be mounted on something for the turns counter to work properly."[/font]

[font=Verdana, Arial, sans-serif]For anyone wanting a quick n easy full proof way to attach a mounting bracket to this power supply and also mount the pot , I have a easy solution ,,,, get a flat piece of aluminium sheet and simply adhere it to the bottom of the supply with The Amazing goop adhesive , it will hold up to the heat fand out last the power supply , same thing with the pot , put a dab of glue on the bottom flat part of the pot and hold it in place with tape , when the goop dries you remove the tape and it will be solid  , .[/font]
[font=Verdana, Arial, sans-serif]Whats it take to solder the wires to the Meanwell ? Is it really that hard?[/font]

 

[highdesertranger]

what ever you are using to copy and paste is making my stomach turn. highdesertranger

 

[Mobilesport]

I'll add that the goop is removable to , , peels off if you want it to otherwise its stay put.

 

[Mobilesport]

what ever you are using to copy and paste is making my stomach turn.  highdesertranger

Forum glitch

 

[blars]

The voltage yoyo might be due to battery heating -- a cold lead-acid can't accept much current, the voltage rises and heats the battery, then the voltage drops when it's warm enough to accept more current.

Reading the manual, the RSP-750 series output voltage and current can be set via external voltages, which could be done via the aux output, a pot, and a couple other resistors. So no unsoldering needed.

 

[Mobilesport]

The voltage yoyo might be due to battery heating -- a cold lead-acid can't accept much current, the voltage rises and heats the battery, then the voltage drops when it's warm enough to accept more current.

Reading the manual, the RSP-750 series output voltage and current can be set via external voltages, which could be done via the aux output, a pot, and a couple other resistors.  So no unsoldering needed.

External voltages ? What do they mean by that?  Are they talking about the voltage from my battery?

 

[SternWake]

External voltages ? What do they mean by that?  Are they talking about the voltage from my battery?

It appears one can influence output voltage by applying another voltage source to two of those 14 pins in that connector.
Honestly a "TTL voltage signal" at this point,  is above my pay grade

http://dtsheet.com/doc/828873/meanwell-rsp-750

Perhaps such a device as this could do it:

https://www.amazon.com/DROK-Waterpr...68306055&sr=8-2&keywords=DC+voltage+converter


I have one of those on my Dash gauge cluster as the   gauge voltage limiter, as it was 1/5th the price of the original mechanical version that used 1930's technology.

The 750 watt Meanwell model has a ton of features more than my 500 watt model.

The process I used for removing original tiny voltage trim pot was rather involved, but could be done smarter in retrospect.

I wound up removing circuit board from the body and desoldering the trim pot tabs with a vaccuum gun/solder sucker, then soldering in 22 awg wires. Then putting it back together.  There are transistors than have a thermal pad insulating the transistor electrically from the casing, but designed to transfer heat well. These  transistors are pulled tightly to the casing with a T bar on the backside.  They use some thermal grease between this thermal pad and casing to assist the transfer of heat from transistor to casing.

This thermal grease is very messy stuff, hard to clean, and one basically needs to clean it off and apply more.  I found my meanwell it was not used liberally enough on one set of transistors.

I used this on reassembly:
https://www.amazon.com/Arctic-Silve...&sr=8-2&keywords=arctic+silver+thermal+grease



In another project:
https://vanlivingforum.com/Thread-Your-Vehicles-voltage-regulator?highlight=voltage+regulator


With a slightly larger potentiometer, I simply took some precision nippers and was able to lift and cut off the metal legs destroying potentiometer, and used the original trim pot legs to solder wires to.  I think if I could get the nippers to the trim pot I would use this method rather than full disassembly. Though it was kind of neat to know I used  a better thermal grease liberally, for perhaps  better heat transfer from transistors to casing, compared to when it left the factory.


On another site someone much better at soldering than myself soldered wires right to the original trimpot legs while it was still in place, and left the original in place.  I am not sure how they got it to work properly with two potentiometers basically in parallel, but they claimed full operation. I guess one turns the original potentiometer to 0 resistance and then turns the external pot on the wires to control voltage.

There is a bunch of capabilities of this 750 watt meanwell that go far beyond my requirements. On my 500 watt model,  I could in theory set up some voltage sense wires to compensate for voltage drop on my cabling, which would be quite useful, but I basically just lower voltage once or twice via the external pot while amps taper from 40 to 0.4 to keep voltage from climbing too high.  But really i don't stress the too high a voltage too much.

Northstar Says 14.46 at 77F, Odyssey says 14.7v at 80F. Mainesail said 14.7v could stave off sulfation in my usage.

My vehicle's voltage regulator held this current agm battery at 14.9v far too often when it was already fully charged, and also brought it upto 14.9v when depleted and highway driving at 60+ amps into the depleted battery.  Recent battery temperature data revealed the battery was likely way hotter than 77f during many of these 14.9v events.
Basically Showing an AGM battery resilience to overcharging/overvoltage I had not expected.

 

[blars]

External voltages ? What do they mean by that?  Are they talking about the voltage from my battery?

I was thinking about a simple resistor divider from the 12v aux output, but I'm not sure it's stable enough. A buck converter would probably waste more power than it saves at this low current, and the output might be noisy which could cause problems. Anyway, this would involve less that a dolor in parts in addition to the 10-turn pot. (78L05, bypass cap, and a couple resistors)

 

[SternWake]

I am not yet familiar with wiring up my own electronics circuits so will defer to blars on this method of external voltage control that the rsp-750-15 allows.

My electronics guy did not/ has not yet gotten back to me on the buck converter being acceptable to feed ' TTL voltage' to pins X and XX for voltage manipulation. But the potentiometer on that buck converter likely is only rated at 2x the cycles of the Meanwells trim pot so not much improvement other than being able to locate the adjustment screw more distant from the MW.

The adjustable voltage powermaxes were nice because they too are PFC and come with an external potentiometer, but poor longevity reports and next to no customer service makes the meanwell the more palatable option, IN my opinion.

Too bad these Meanwell's don't come with a real finger twist potentiometer for adjusting voltage, but these were never designed to be used as battery chargers where easy voltage changing ability is desirable.

 

[SternWake]

Okay, My electronics guy got back to me regarding TTL voltage, but it accellerated as it flew over my head.

A TTL signal is plain old 1 and 0 digital logic, using transistors (as opposed to CMOS) as used in a digital computer. It means Transistor-Transistor Logic. This "form" of name refers to the architecture too; the coupling between logic elements is directly from one transistor to another. There were other forms of coupling too, like RTL, for Resistor-Transistor coupling, between transistors and CMOS, or transistors of different operating levels, like would be used in line drivers such as in an RS-422 cable, and there were even some variants of transistor coupling, like ECL, which took the signal from the emitter of a transistor rather than the collector, to increase speed.

Transistors require current to bias them on, so they generate quite a lot of heat, unlike the CMOS technology chips which are far more energy efficient, so TTL logic has mostly been sidelined.

The voltage of a TTL signal will be from 0.0 volts as a low logic level to 5.0 volts as a high logic level, with the transition from low to high typically being around 1.7-2.5 volts.

This is not all that dissimilar to the PWM signal used to operate your variable speed fan. The pulse width on most TTL logic is fixed however, by rigidly following a master clock on the circuit board. It doesn't have to be fixed, though when it's not it's considered asynchronous, which adds the complexity of additional circuitry because you have to have buffers and latches to hold/remember the logic signal for when the next clock cycle comes along for the rest of the logic circuitry to act.

Since TTL is a simple on or off logic, I'm not entirely sure how you would control a power supply with it...

Perhaps it actually is a PWM input, which just happens to have been designed to accept 0v to 5 volts as its input level, so they're calling it TTL for convenience. Since it's Chinese, such fine points in translation often become blurred... I've seen a similar TTL logic reference used for the inputs to the laser show controllers on Chinese laser shows.

Hope that helped a little?

Sure seems easier to remove the tiny provided trim pot and replace it with a 10 turn Bourns of appropriate resistance.

 

[BradKW]

lol, I love engineers...3 pages in to say "umm, yeah...I don't know."

Got a couple good buddies that are engies, and the above fits so perfectly with a running joke from 20yrs ago I will have to share this.

 

[Mobilesport]

I went to plug my 4 gage battery cables into the Meanwell and they were to big , , the Meanwells holes are way smaller then the Powermaxes , see photo

 

[Mobilesport]

Photo

 

[Mobilesport]

Photo

Ok   I didn't want to but I trimmed a bunch of strands off of the 4 gage wire ends , got em to fit , plugged it in and light came on but amps only read 30 amps , volts only read 11.9 which is what my batteries voltage is right now , so I'm lost at this point , I'm going to go take a break and come back and try to figure it out.

 

[SternWake]

Ok   I didn't want to but I trimmed a bunch of strands off of the 4 gage wire ends , got em to fit , plugged it in and light came on but amps only read 30 amps , volts only read 11.9 which is what my batteries voltage is right now , so I'm lost at this point , I'm going to go take a break and come back and try to figure it out.

Order of events here?

Did you adjust unloaded voltage to 14.8v? Unloaded meaning not hooked to depleted  batteries?

30 amps should have been able to start raising voltage above 11.9 rather quickly, as long as meanwell voltage was set to 13.6v or higher.

Voltage is electrical pressure. without a voltage differential between Meanwell and battery, no amps will flow.

Output voltage must be set to ~14.xX Volts, unloaded.

 

[Mobilesport]

@Sternwake
Yes , the first thing I did was adjust the mean wells output to 14.8volts , and yes I adjusted the voltage while my house batteries were not connected to the output , the only thing I had at the out put was my positive and negative voltmeter leads.
Ok so after hooking up my house battery to the Meanwell I powered the Meanwell up and took a amp reading with my clamp meter ,,, it was 20 amps ,, voltmeter reading was 11.9 volts.
I left powered up and the amps kept rising but the volts stayed the same or actually the volts droped to about 11.7 volts over a period of time , I'm not sure of the time period but I could say it was definitely at least 15 minutes , could've even been 40 minutes but at the end of that time the amp reading was up to 50 amps and still climbing but voltage was the same 11.7 volts . 
I measured voltage at the meanwells output and at the house batteries and both readings were 11.7 volts .
I shut it down.

 

[SternWake]

@Sternwake
Yes , the first thing I did was adjust the mean wells output to 14.8volts , and yes I adjusted the voltage while my house batteries were not connected to the output , the only thing I had at the out put was my positive and negative voltmeter leads.
Ok so after hooking up my house battery to the Meanwell I powered the Meanwell up and took a amp reading with my clamp meter ,,, it was 20 amps ,, voltmeter reading was 11.9 volts.
I left powered up and the amps kept rising but the volts stayed the same or actually the volts droped to about 11.7 volts over a period of time , I'm not sure of the time period but I could say it was definitely at least 15 minutes , could've even been 40 minutes but at the end of that time the amp reading was up to 50 amps and still climbing but voltage was the same 11.7 volts . 
I measured voltage at the meanwells output and at the house batteries and both readings were 11.7 volts .
I shut it down.

50 amps flowing into batteries would indicate a high voltage differential between meanwell and battery.
This voltmeter, is it a digital voltmeter or ths 4 wire voltmeter you salvaged from another project.

50 amps would not flow if battery voltage was 11.9 and voltage would not drop further under 50 amps unless the meanwell were sucking 50 amps as a load, which would likely self destruct it.

Your readings make little sense.  50 amps flowing would increase super depleted battery 220AH of capacity into the low to mid 13's nearly instantly.

If there is not measurement error somewhere, i am stumped.  try hooking up the voltage sense wires to the output too,or better, to battery terminals.

My digital multimeter is highly inaccurate when its internal batteries are nearly dead.

I'll be offline for the next 8 hours minimum

 

[highdesertranger]

Stern you need a gone surfing sign.



highdesertranger

 

[SternWake]

I have that tattooed on the back of my skull, but still have thick hair.