Problems with Boondocker 60 amp converter
Having issues with this converter, won't do more than 13.6 volts, ever.
Forum Discussion
I use the full voltage range of my Meanwell rsp-500-15( well, below 16v anyway), and with the original trim pot this range was from 13.23 to 19.23v.
With the original 1K ohm pot in both the cheapowatt and the MeanWell, 0 ohm resistance on the pot, the PS goes to its maximum voltage, maximum resistance and the PS goes to its lowest voltage.
The Cheapowatt and Meanwell came with a 1000 ohm pot. I measured the original trim MW pot upto 970 ohms( going by memory here)
The 10 turn pot measured 995ohm( again memory)
With the new pot wired in with its ~20 more ohms of resistance, minimum voltage dropped to 13.12v, down from 13.23v.
So I assume if I were to use a 500 ohm pot on my Meanwell, I would lose the lower ranges of voltages, which would not be desirable for me as I use mine to float my battery once full.
I am not sure the original voltage range on the Megawatt, I thought 15.5v was their maximum, and Niner has no use for the Megawatt to float his battery at a lower voltage, and perhaps never noticed that the voltage does not go as low as it did with the original 1000 ohm potentiometer. And the markings shown in photos on the pot of the MW indicate it is a 1K ohm potentiometer.
The 10 turn pot I used on my Cheapowatt and then the Meanwell is this type:
http://www.amazon.com/WXD3-13-Shaft-Turn-Wound-Potentiometer/dp/B00R1LTWFK/ref=sr_1_7?ie=UTF8&qid=1454543081&sr=8-7&keywords=10+turn+1K+ohm+potentiometer
It is not very high quality as it developed uneven spots Which some DeOxit F5 fader lube resolved. But the spots came back and a second application resolved them again, but once again they are slowly returning, but it is easy enough to loosen the 3 screws pull it apart enough to get the red squirter hose in there and reapply.
These uneven spots cause my Meanwell to click on and off when adjusting voltage.
I recently got a 2K ohm pot for another project, that has the same appearance of the Pot niner shows. It is heavier than I expected. The turns counter feature is awesome and it has a brake on it too. I checked it through its 3600 degree range with my DMM and it was smooth and steady the whole way. I'd have to recommend this type over the type in the link above though I know not how it will last after a few dozen cycles. I ordered mine through Ebay for under 5$. It took 9 weeks to arrive, I was about to give up on its arrival.
If one has the confidence and skills to solder in their own wires for an external 3600 degree potentiometer, get some thermal grease to reapply between the transistors and the casing.
a 500 ohm range of adjustment over 10 turns would certainly allow more precision when adjusting voltage, but it is quite easy to dial it into 0.01 a volt with a 1K ohm potentiometer at half the sensitivity.
I would NOT use a 2K ohm pot to replace a 1K ohm pot. I imagine the magic blue smoke could escape.
The Powermax adjustable voltage model's potentiometer's range is less than 360 degrees. It is very touchy to dial it in to 0.01 of a volt, practically impossible, but someone seeking 40+ amps in a manual Adjustable voltage premade package, should consider one of these instead of trying to convert a MW power supply to an external potentiometer.
With the original 1K ohm pot in both the cheapowatt and the MeanWell, 0 ohm resistance on the pot, the PS goes to its maximum voltage, maximum resistance and the PS goes to its lowest voltage.
The Cheapowatt and Meanwell came with a 1000 ohm pot. I measured the original trim MW pot upto 970 ohms( going by memory here)
The 10 turn pot measured 995ohm( again memory)
With the new pot wired in with its ~20 more ohms of resistance, minimum voltage dropped to 13.12v, down from 13.23v.
So I assume if I were to use a 500 ohm pot on my Meanwell, I would lose the lower ranges of voltages, which would not be desirable for me as I use mine to float my battery once full.
I am not sure the original voltage range on the Megawatt, I thought 15.5v was their maximum, and Niner has no use for the Megawatt to float his battery at a lower voltage, and perhaps never noticed that the voltage does not go as low as it did with the original 1000 ohm potentiometer. And the markings shown in photos on the pot of the MW indicate it is a 1K ohm potentiometer.
The 10 turn pot I used on my Cheapowatt and then the Meanwell is this type:
http://www.amazon.com/WXD3-13-Shaft-Turn-Wound-Potentiometer/dp/B00R1LTWFK/ref=sr_1_7?ie=UTF8&qid=1454543081&sr=8-7&keywords=10+turn+1K+ohm+potentiometer
It is not very high quality as it developed uneven spots Which some DeOxit F5 fader lube resolved. But the spots came back and a second application resolved them again, but once again they are slowly returning, but it is easy enough to loosen the 3 screws pull it apart enough to get the red squirter hose in there and reapply.
These uneven spots cause my Meanwell to click on and off when adjusting voltage.
I recently got a 2K ohm pot for another project, that has the same appearance of the Pot niner shows. It is heavier than I expected. The turns counter feature is awesome and it has a brake on it too. I checked it through its 3600 degree range with my DMM and it was smooth and steady the whole way. I'd have to recommend this type over the type in the link above though I know not how it will last after a few dozen cycles. I ordered mine through Ebay for under 5$. It took 9 weeks to arrive, I was about to give up on its arrival.
If one has the confidence and skills to solder in their own wires for an external 3600 degree potentiometer, get some thermal grease to reapply between the transistors and the casing.
a 500 ohm range of adjustment over 10 turns would certainly allow more precision when adjusting voltage, but it is quite easy to dial it into 0.01 a volt with a 1K ohm potentiometer at half the sensitivity.
I would NOT use a 2K ohm pot to replace a 1K ohm pot. I imagine the magic blue smoke could escape.
The Powermax adjustable voltage model's potentiometer's range is less than 360 degrees. It is very touchy to dial it in to 0.01 of a volt, practically impossible, but someone seeking 40+ amps in a manual Adjustable voltage premade package, should consider one of these instead of trying to convert a MW power supply to an external potentiometer.
