There is a slight issue with photos but that looks like one WELL BUILT device.
The photos came from my Photoshop notes on top of the photo, where I can blow up the vector text to read it when working. I saved as JPG, and checked that I could read the JPG, but somewhere the res was reduced.
One thing you can get off the photos is the pinout/connection for the remote. It's marked - LED, Switch and Ground. The LED lead goes to the positive lead of your LED and the other LED lead goes to the Ground lead . Your switch goes between Switch and ground. Shorting the Switch lead to ground causes the PD to change modes (brief goes into Boost mode, 3 secs goes to normal and longer than 6 goes to float) and the LED will flash to indicate the mode you are in. It uses modular connector (phone handset).
Motorcycle carrier is way more important. I never leave without my Yamaha XT225. I added 2 extra 1 1/4" hitches to stabilize the cycle carrier. It made a huge difference in keeping the cycle from bouncing around.
We have the Yamaha XT200 that we usually carry for dual fun, an IT200 enduro when I want to play alone in the woods, and an XT 350 that's a bit too heavy for the bumper. The carrier has been there since 1986, and is only off now because it needs to be modified to fit the septic hose carrier I'm adding now.
The Jeep goes behind with the kayak and Canoe on top.
IF PWM controlled, you can adjust the feedback circuit to change (increase) the duty cycle which will in effect, increase the supplied current. However, I am just guessing without looking at the schematic and feedback loops.
The duty cycle is controlled by the UC3xxx chip (forgot the number it is posted in this thread), which is designed specifically for this job. It has a voltage limit input and a current limit input. They should produce constant current up to the voltage limit. However, there are some other inputs to that chip (short circuit protection, etc.), and the PD design may have some crosstalk between the voltage produced by the current sensing input and the voltage input to the duty cycle control. That was what drove my mods 2 and 3. I fooled the chip into thinking it was running at lower current, and then reduced the current limit in the hopes of reducing potential voltage based current/voltage crosstalk resulting from the circuit in which that chip was embedded.
Posting a short msg from my phone:
The transformer can be replaced or turns ratio modified, but we agree, that's not the easiest solution. I remain unconvinced that is the problem - it may just be control related. It's annoying, as I have the stuff needed to test it, but I just can't do it yet. I'm in the middle of several other RV projects now (remote water pump switch and waste hose storage and motorcycle carrier and cargo carrier), and don't want to drop those to scratch this curiosity itch. I will eventually, as I'm pretty sure the itch won't go away. :)
We agree on the issues in regards to the PD. I don't however believe you can fix the problem by modifying the PD front end. "By "front end", I presume you mean the capacitor peak charge circuit. I believe the transformer is at fault. It doesn't have enough turns-ratio to output 14.4 at minimum cap bank voltage.
The minimum ac voltage the converter is supposed to supply full current is 105Vrms. That translates to a cap bank voltage of:
V_cap = 105Vrms * sqr2 - 2 * Vd = 152V - 2V = 150Vpeak
You want to operate at least 20V below peak voltage.
The minimum transformer turns ratio is:
N_min = (V_cap - 20V) / V_reg
N_min = 130V / 14.4V = 9
If you look at the PD patent, I bet you'll find the transformer turns ratio is higher than 9.
The issue was that some generators don't make clean power while inverter gens do.
The advantage of an inverter gen is that it can run at low speed when minimal power is required. That reduces noise, pollution and fuel use. The shape of the sine wave ("clean" or not) is dependent on the design of the inverter circuit. Just like we have MSW and PSW inverters, there can be MSW and PSW inverter gens. I'd expect a good inverter gen making a perfect sine wave to work well with all chargers, but other inverter gens producing a different waveform might perform much worse than a non-inverter gen.
Again, as much as Wayne tried, he can't charge his batteries with 60A. The current tapers before converter voltage gets to 14.4V. If the converter was in regulation, it would increase its output voltage to maintain 60A. That's how converters work. Current should start to taper after 14.4V is reached. Not before!
Let's clarify a point I'm pretty sure we both agree about - relating to remote voltage sensing. The PD and Iota and others that do not have remote voltage sensing will start to taper when the charger is at 14.4 volts, even though the battery is not yet at 14.4 volts. That's why it's so important to have short fat charger cables.
Other than that, we agree. If the charger is tapering below its set current limit, while the voltage is below its max setting (for mine the voltage is 14.8 volts per Trojan recommendations) then something is wrong. It could be an input stage problem - there's not enough voltage to increase the current, or it could be a control issue.
I made some mods I thought would help if it was a control issue. I studied the datasheet for the control chip in the PD series, as well as the PD circuit. There are several interconnections that could have caused premature current tapering.
Unfortunately, my early unmodified tests were at a low voltage, so the tapering could have been due to either problem. Then I tested at higher voltage, after modifications. There was an early increase in current then later tapering. From those two tests, I still don't know where that problem came from. We agree that the properly designed circuit should not taper current until the charger reaches its design voltage limit, or it is simply unable to supply that current.
If it's unable to supply the current, there are some possible fixes. One can boost voltage at the gen. One can boost voltage with a buck/boost autoformer. One can even modify the input stage of the PD. I chose the easiest for me.
AFAICT the UC PWM current mode controller that the PD uses to control the output is designed to work as described above. I don't yet know why the current isn't absolutely flat up to the voltage limit as I would expect from reading about the control chip. It may be an interaction from other parts of the circuit (there is a current limit and a short circuit protection and some other elements that may interact in the control system), or it may be running out of power from the input stage when operated at low voltage.
The thread is too long to go back. As I recall, we had this discussion before. You acknowledged boosting the ac input voltage.
I agree it's too long to go back :)
I tested once at 105 VAC on an extension cord. I tested once at 113 VAC with the generator cranked down (Onan CCK 4.0) at 113 VAC. Those are voltages with the PD9280 at full load. With the PD9280 off, the voltages were higher. I regularly operate the generator above 120 volts loaded, but did not record the data from those runs, as the run at 115 VAC was satisfactory.
As I understand it, the Onan MicroQuiet generator does not produce a pure sine wave.
The Onan Quiet Diesel is an inverter gen. I'm not familiar with the microquiet line, but you could be right. In general, the input circuits rely upon the peak voltage to charge and they can suffer with modified sine wave or square wave outputs of the same RMS.
Those powering a PD with an Onan will have a very difficult time getting anywhere near full current. If your generator is not pure sine, the PD will suffer. .... The mods won't help.
You could well be right. I already owned the PD, and the mods were made 1) to increase output voltage and 2/3) because I thought there was in interaction between the sensed current and the duty cycle of the charge circuit. It could not compensate for a problem at the input stage, but Wayne Dohnal's testing and other indications led me to believe that the PD could output more current than it was outputting. If that was the case, it was a control issue, not an lack of power at the input stage. The modifications to the current stages were made to address the possibility that it was a control issue. I didn't worry about it if it was a lack of voltage at the input stage, since I had control over that voltage by controlling my generator output voltage.
If anyone is looking for a fast battery charge, or doesn't want to run the gen for longer time periods, then going with a different converter is a better option.
I won't disagree with this, except to note that 1) the PD will let me decide to turn on boost mode. I don't know what other brands will do, and 2) the PD is the only model that has circuit diagrams available, and that's important to me. I get to select the voltage and current limits I want.
I can get faster charging with the PD using its boosted voltage mod and OEM override for entering boost mode than I can with my other chargers, which will not enter boost mode when I want, and won't charge to the voltage I want.
I like that when I know my batteries are fully charged, I can put the PD into float mode. If I'm plugged in, I can just switch it to normal mode and let it do its thing. If I know I need to charge up, and I'm only going to be running the gen long enough to run the MW, then I can force it into boost mode and get the maximum benefit out of that short gen run. I like that I can add multiple charger controls for the PD, so there's a control near my generator starter, and another near the batteries for when I'm working on them.
Other chargers do just what they were programmed to do. For many people, that's all they want or need.
Wayne Dohnal did that test. The converter load was a roll of copper cable. The PD output 60A at 13.4V. His 60A PD could not do 60A into his batteries. The current tapers.
We've disagreed about this before. If the charger outputs 60A at 13.4, then it doesn't matter if it's sending that current into a roll of wire or a battery. That's the current it supplies at that voltage and that's why Wayne did that test that way. It allows one to repeatedly test current output without guessing about the state of the batteries one tests with.
Fisherguy's results (second graph down) is the general example we have been using.
That's interesting. He's got about half the capacity in that test as I used. Mine is 460AH. In roughly 50-60 minutes his dropped from 80A to 60A. I assume he gave it enough voltage (an assumption that may not be warranted).
Compare to the results in my unmodified PD9280 testing at 105VAC. In mine, the early taper took closer to 3 hours due to the larger capacity and the lower voltage (I assume it's lower, I'm not sure what voltage Fisherguy supplied).
It makes me wonder if the mods (2 and 3) I made actually did account for some of the reduction in current tapering I hoped for.
ISTR there were reports that PDs don't work up to speed with Onans or some Onans due to wave form issues with the Onan's output. They work ok with inverter gens or shore power. Can't remember the details so whether it would apply here, sorry.
I have tested my PD9280 on an Onan CCK 4.0KW gen. It works great at any normal operating voltage (above 113 VAC, and I usually run at 120+ VAC). My PD has been modified to produce higher output voltage (14.8V instead of 14.4V), so it produces close to constant current for longer (to a higher final voltage) and still has no trouble. I had heard the opposite - that PDs had trouble with inverter gens, but I am very leery of some of these comments.
My Onan CCK is a rotating armature design, not a rotating field or inverter design, and that could have some bearing on my tests.
What size is that thermistor on the 80amper?
As I posted the photos, I knew you'd ask that question :) :)
I don't have the PD open, but I do have good photos. I'll try to see if I can read the value from those, although it wasn't a part of the circuit that I was focused on when I took the photos.
I don't believe these mods will keep the PD in constant current during boost mode. The main complaint of the PD is that it tapers current right after turn-on. A 60A PD can't charge at 60A.
You can review the performance tests from the graphs posted in this thread. It increases current to about 84A when initially turned on from 50% SOC over the first 1-1.5 hours, when powered with my generator at 113 VAC, then falls over the next 1-1.5 hours to 75A. I didn't do this test with mods when powered from my 105 VAC shore power line. I did do it without mods on 105 VAC shore power - results also posted - and it shows a taper. It isn't clear to me if the performance difference is solely due to AC differences or the mods plus AC.
However, WoodIsGood is looking to decrease current output, so this issue shouldn't affect him.
I would be very interested in any testing by others. I have the stuff needed to do testing, just not the time (plus the batteries are out for the winter).
I'm not convinced that the PD does initial tapering, even unmodified, if the voltage is at least 113 VAC, although I agree that higher voltage is better and there is tapering at 105 VAC, unmodified, as shown in my own testing. The only other testing I've seen that I'm convinced was done correctly used a straight resistive load, and measured the output. That is the best way to measure the effect of different AC voltages at input. That testing showed little or no tapering IIRC.
I suggest for those who want to make the mods, first document PD performance before making changes. Discharge batteries to 50% SOC (about 12.1V). Turn on PD and measure charging current and battery & converter voltage. For the first 5 min, take measurements every minute. The following 10 min, take measurements every 2 min. Then measure every 15 min. You can also assemble all meters in one location and take a video of the charge profile. Run the same test after making any mods.
I agree. I had two purposes in making the mods. The first was to control the boost voltage. That mod works perfectly. I may eventually add in automatic temperature compensation, but right now my manual output voltage control is enough.
The second was to deal with the perceived issue of current tapering that some posts spoke about. At 105 VAC I saw that issue myself. That is the voltage of my shore power extension cord when feeding the PD9280 at full throttle. Unfortunately, I didn't test at 113 VAC or my normal generator operating voltage of above 120 VAC.
I don't know if the mods had any effect on the current tapering issue, or if it was solely an AC voltage issue. Since I don't see it when charging with my gen, and don't care about fast charging if I have shore power connected, I haven't done the final testing needed to resolve the issue.
There have also been comments that the PD series has trouble with AC produced by inverter-type generators. I have no personal information about that, beyond what is posted above. I'd like to see proper testing of that issue as well, but since I don't have an inverter gen, I can't do such testing. I will eventually do AC voltage testing eventually, just to resolve that issue in my own mind.
I'd be very interested in any testing done by others.
Here are some labeled photos with some circuit info from my notes:
I'm sorry the text is so hard to read, but it should be possible to identify the resistor that needs to be decreased in value (by adding a resistor in parallel) to increase the output voltage. these resistors relate to the microcontroller (lower left when seen from the top) which just changes the output voltage. The resistors that control current sensing, voltage sensing and current limits are covered in the patent.
I'll also add that to get into the PD9280, there are two rivets that should be drilled out with a 1/8" drill and replaced with a 1/4" hex drive screw - like several other screws already on the case.
No, I meant ...Don't short your converter.
Ah! I see what you were recommending. You were referring to the difference between a shunt regulator and a series regulator. The former short circuits the current source and the latter open circuits it.
You are right, of course, but I assumed he wasn't asking about that issue. I thought he was asking about using the cables from the output of the converter to make connection to the batteries (to avoid running a new set in parallel).
Do you guys even read the actual question by the OP ??
I'll admit, I sort of wondered the same thing, but the answers were all relevant.
Reading between the lines, the OP has batteries at one end and the converter/charger and solar controller at the other end of the
RV. I think he was asking whether it was OK to keep the solar controller far from the batteries and connect the output of the solar controller to the output of the converter/charger and use the existing heavy duty cables that run from the converter/charger to the batteries to carry the current from his solar controller to the batteries.
I took the answer by BFL "Yes, the converter and controller outputs should be in parallel on the batteries. Wrong to have the converter output go to the controller's input "to be a typo and he meant to say that it is "Wrong to have the converter output go to the controller's output (not input)"
I'm not particularly comfortable providing advice on this, as I don't have solar. Nonetheless, if the cables from the converter are really heavy gauge, I don't see much harm to this. I'd expect that the converter will usually be off when charging with solar, and if not, the solar isn't all that critical. It would be better to have short fat cables for both and to have them separate, but perhaps it's not practical.
The answer is that we need more info to go past the excellent post by Old Biscuit.
I don't disagree with his post, but the graphic in that post is of limited usefulness. For example, it shows the inverter directly feeding the AC Breaker Box. That implies everything the breaker box feeds gets powered by the inverter, which is almost never true. It should show that it only feeds some of the circuits in that box and not the air conditioner and Converter/Charger in a normal install.
The graphic shows the AC Breaker Box feeding the Converter/Charger. There's a note saying that the link between those two is broken if there's no AC power from the pedestal or generator, but it would have been better to show *how* that link is broken - with an ATS, which can be separate or built into the inverter. I would prefer a graphic that has the inverter located after the breaker box and an ATS between the two. I'd also prefer that it divide up the "AC Appliances" and "AC Outlets" into those appliances/outlets driven by the inverter and those, like the air conditioner, Converter/Charger and (usually) the propane/AC refrigerator that are not (in a conventional installation).
I think he is wanting info for battery/inverter/tranfer sw. load center only, no genny involved.
It's also not quite clear to me what he's asking. If it helps - my setup uses two transfer switches. One TS is positioned before the AC breaker panel and selects between gen and shore to provide 120 VAC to all breakers. The second TS is positioned after the breaker panel on a single branch circuit and selects between 120VAC in (fed by the breaker panel for that branch) and the inverter. That branch circuit feeds most AC receptacles, but not the air conditioner, fridge or converter/charger.