I have too replaced the stock fan (Sunon Maglev ME80251v1-000C-A99) in my DP-832 with Noctua NF-A8 FLX. But instead of increasing the load with a shunt resistor, I opted for changing R44 resistor value from 7.5 to 22 ohms. This resistor sits on the bottom PCB near the fan connector and works as a sense resistor. Basically the PSU detects if the fan is working based on the voltage drop over R44. You just need to change the value so the drop stays about the same after replacing the fan. This way no power is wasted on the shunt resistor. And it is actually quite easy to get the bottom PCB out. But apparently they changed the sense resistor from a single THMD job to an arrangement of SMD resistors in newer revisions of the PCB (mine is from 2014).
A quiet fan / workshop is bliss. Probably nothing but the resistor is dissipating around 3W so the warming surrounding heatshrink may try and strangle the resistor and produce a nice smell to add to the ambience.
It is odd that they check the fan current rather than monitoring the fan speed using a fan with a pulse sensor, I wonder what happens to the fan current when you stop it turning?
Found this just as alarms went off at work - I built an IMSAI back in the 80's. I couldn't afford fancy things like monitors or terminals, so I programmed it with the front panel and built homebrew hardware control projects. Man, those were the days!
A similar fan mod on my iCom ID-880H made a heck of a difference….and you can get them in a bigger size for the 7300 and 9700 too, I believe. Amazing how much quieter they are.
I plan on doing the same to my DP1308A, but at first I just installed a regulator in line with the fan supply and crancked it down to slightly before it complains about the power consumption and trips. It isn't being a problem for now, since I am not using it at higher currents.
I have a palstar ps50 big linear PSU to run my radio equipment, that runs a 120mm 24v fan just switched on and off at full speed via a simple comparator circuit. I ended up installing an Arduino to monitor the temperature and pwm the speed of the fan, even managed to use the original transistor that switched the fan with the pwm from the Arduino. Now it never runs at full speed as, as soon as the temperature starts to rise the fan starts up slowly and starts to cool things down. I now don't have to listen to a jet taking off if I TX for too long 😀
Cut away the finger guard at the back, this will increase the air flow. Is you want a guard put a wire one on the outside. If you want more air flow put a send fan on the outside.
That's what I do. It also cuts down noise because of less turbulence. Or do both fan and guard mod with a slightly slower quieter fan, and still have the same airflow as stock.
Wondering why manufacturers don't monitor the tacho output generically available on fans of that type. It's a digital input into the microcontroller so "cheaper" than analog voltage measurement of current draw.
From one old fart to another, I get the shaky hands days as well. Usually when I'm doing smd work! Lol. Serious question though... does the Noctura fan move enough cfm to keep the Rigol power supply cool under load? Ive used them in 3d printing before to try and keep the hot end cool only to find they can't keep up. Does the Rigol display an internal temp you could reference?
I have the DP832 noisy fan power supply. I really like reducing the fan noise in my equipment and I have also have used Noctura fans. I am with you and I am not a big fan of the color scheme (get it? big fan ; ) One big concern/question: Will the replacement fan move sufficient air for proper cooling? The NF-A8 FLX can rotate at a maximum speed of 2000 RPM and the maximum airflow is 50.4 cubic meters per hour. I know it may be difficult to get those specs on the original fan but I use an inexpensive anemometer to compare the air flow of fans. When the Noctura only draws a maximum of 0.8 watts, which is much less than the other fan I would be worried that it might not be moving enough air even if the bearings and blades are more efficient. A test could be to run your power supply under full rated load and see if it over heats or shuts down. Again I think the best way is to measure the airflow of the original fan and then replace it with something similar. Thanks for the video, I enjoy your channel.
From some informal testing (don't have an anemometer at hand) the noctua has less than 50% of the flow of the original fan. I'm still going ahead with the swap because I rarely run the Rigol at high sustained power. But your warning is absolutely correct and valid. Edit: the official spec for the Sunon Maglev ME80251v1-000C-A99 is 41 cfm = 69.6 m3/h compared to the 50.4 m3/h of the Noctua, so it's not so bad as I thought.
Didn't you use one of the three supplied adaptor cables on your fan to avoid cutting the fan's own cable when you added the 2 pin plug from the original fan? Those cables all come with resistors in them which reduce the fan speed from the unadapted speed of 2200 down to 1650, 1500 and 1200 or something.
I love my HP54622A scope but it's got a fan like a jet engine. It's a specially made high-volume blower. The service manual even cautions against running it with the case off -- that you should position an external fan blowing across the innards. Is this just excessive paranoia? I don't see oversized heat sinks in the power supply that look like they'd need a lot of air. The whole thing's only, what, 30 watts?
@@IMSAIGuy are you sure ? I found the original sunon fan had twice the airflow. I thought the Noctua was better but i notices the specs were in m³/hrs vs cfm for the sunon original fan. I still like the noctua, it is so much quieter. OY1R
@@Dreamlgider With half the wattage rating, I would assume the Noctua moves a lot less air. When it comes to case fans, there is no replacement for static pressure to cool things down.
I've never been impressed with the vast majority of Sunon's efforts. At some point between when I was in college EE labs and when I bought my own E3631A (new), HP/Agilent/Keysight/whatever they're calling themselves this week revised the design and removed the rear chrome fan grill and went to one that was just stamped into the cover (aluminum enclosure --> steel). Also during this time Panasonic obsoleted their entire Panaflo line (for no good reason), forcing Agilent to go around and find a fan that had a similar blade design to stick in there, resulting in kind of an odd, protracted bait-and-switch. At least the supply did what I expected. It was a noisy match made in hell. It wasn't even a *good* Chinese fan. WTF? I tried out a couple of other fans in there and settled on a Papst because it wasn't running in stall and going turbulent like everything else. I can't remember the part number, but if I remember correctly I was going for something that was close to the original Panaflo or whatever they stuck in there in terms of specs. The original cheap and nasty fan was killed in an appropriate manner. The little bastard didn't even have polarity protection. :)
I have too replaced the stock fan (Sunon Maglev ME80251v1-000C-A99) in my DP-832 with Noctua NF-A8 FLX. But instead of increasing the load with a shunt resistor, I opted for changing R44 resistor value from 7.5 to 22 ohms. This resistor sits on the bottom PCB near the fan connector and works as a sense resistor. Basically the PSU detects if the fan is working based on the voltage drop over R44. You just need to change the value so the drop stays about the same after replacing the fan. This way no power is wasted on the shunt resistor. And it is actually quite easy to get the bottom PCB out. But apparently they changed the sense resistor from a single THMD job to an arrangement of SMD resistors in newer revisions of the PCB (mine is from 2014).
A quiet fan / workshop is bliss. Probably nothing but the resistor is dissipating around 3W so the warming surrounding heatshrink may try and strangle the resistor and produce a nice smell to add to the ambience.
And when your new fan stops working, the resistor draws enough current so auto shutdown does not work anymore?😱
It is odd that they check the fan current rather than monitoring the fan speed using a fan with a pulse sensor, I wonder what happens to the fan current when you stop it turning?
yes, seems pretty strange.
Found this just as alarms went off at work - I built an IMSAI back in the 80's. I couldn't afford fancy things like monitors or terminals, so I programmed it with the front panel and built homebrew hardware control projects. Man, those were the days!
I've got over 70 videos on my old IMSAI, start at #1
A similar fan mod on my iCom ID-880H made a heck of a difference….and you can get them in a bigger size for the 7300 and 9700 too, I believe. Amazing how much quieter they are.
I plan on doing the same to my DP1308A, but at first I just installed a regulator in line with the fan supply and crancked it down to slightly before it complains about the power consumption and trips. It isn't being a problem for now, since I am not using it at higher currents.
Not wrong about the heat gun. Does it generate heat by rubbing rocks together? 🤔😁
Thank you for the video. What were the specs on the resistor you used?
I have a palstar ps50 big linear PSU to run my radio equipment, that runs a 120mm 24v fan just switched on and off at full speed via a simple comparator circuit. I ended up installing an Arduino to monitor the temperature and pwm the speed of the fan, even managed to use the original transistor that switched the fan with the pwm from the Arduino.
Now it never runs at full speed as, as soon as the temperature starts to rise the fan starts up slowly and starts to cool things down.
I now don't have to listen to a jet taking off if I TX for too long 😀
Cut away the finger guard at the back, this will increase the air flow. Is you want a guard put a wire one on the outside.
If you want more air flow put a send fan on the outside.
That's what I do. It also cuts down noise because of less turbulence. Or do both fan and guard mod with a slightly slower quieter fan, and still have the same airflow as stock.
I would hope they have temperature sensors around the pass transistors to protect them. That's what I would expect for a power supply of this price.
speaking of testing things out beforehand, how many times have we soldered up connectors only to find the back shell missing when your done ? :-)
way way too many
Wondering why manufacturers don't monitor the tacho output generically available on fans of that type. It's a digital input into the microcontroller so "cheaper" than analog voltage measurement of current draw.
From one old fart to another, I get the shaky hands days as well. Usually when I'm doing smd work! Lol.
Serious question though... does the Noctura fan move enough cfm to keep the Rigol power supply cool under load? Ive used them in 3d printing before to try and keep the hot end cool only to find they can't keep up. Does the Rigol display an internal temp you could reference?
I checked the airflow numbers before I ordered the fan. it is greater airflow. I see no way to display any temp
I have the DP832 noisy fan power supply. I really like reducing the fan noise in my equipment and I have also have used Noctura fans. I am with you and I am not a big fan of the color scheme (get it? big fan ; ) One big concern/question: Will the replacement fan move sufficient air for proper cooling? The NF-A8 FLX can rotate at a maximum speed of 2000 RPM and the maximum airflow is 50.4 cubic meters per hour. I know it may be difficult to get those specs on the original fan but I use an inexpensive anemometer to compare the air flow of fans. When the Noctura only draws a maximum of 0.8 watts, which is much less than the other fan I would be worried that it might not be moving enough air even if the bearings and blades are more efficient. A test could be to run your power supply under full rated load and see if it over heats or shuts down. Again I think the best way is to measure the airflow of the original fan and then replace it with something similar. Thanks for the video, I enjoy your channel.
From some informal testing (don't have an anemometer at hand) the noctua has less than 50% of the flow of the original fan. I'm still going ahead with the swap because I rarely run the Rigol at high sustained power. But your warning is absolutely correct and valid.
Edit: the official spec for the Sunon Maglev ME80251v1-000C-A99 is 41 cfm = 69.6 m3/h compared to the 50.4 m3/h of the Noctua, so it's not so bad as I thought.
@@RemcoStoutjesdijk Thanks for the information.
Didn't you use one of the three supplied adaptor cables on your fan to avoid cutting the fan's own cable when you added the 2 pin plug from the original fan?
Those cables all come with resistors in them which reduce the fan speed from the unadapted speed of 2200 down to 1650, 1500 and 1200 or something.
I love my HP54622A scope but it's got a fan like a jet engine. It's a specially made high-volume blower. The service manual even cautions against running it with the case off -- that you should position an external fan blowing across the innards. Is this just excessive paranoia? I don't see oversized heat sinks in the power supply that look like they'd need a lot of air. The whole thing's only, what, 30 watts?
small heatsink = bigger fan. it probably has a circuit that does not meet spec unless pretty cool. probably HP overkill
I love youre coolness.
Is the new fan strong enough for cooling the supply down?
the cfm is better
@@IMSAIGuy are you sure ?
I found the original sunon fan had twice the airflow.
I thought the Noctua was better but i notices the specs were in m³/hrs vs cfm for the sunon original fan.
I still like the noctua, it is so much quieter.
OY1R
@@Dreamlgider With half the wattage rating, I would assume the Noctua moves a lot less air. When it comes to case fans, there is no replacement for static pressure to cool things down.
"And It's not complaining", I could not hear the fan running at all, could you hear it ?
I've never been impressed with the vast majority of Sunon's efforts.
At some point between when I was in college EE labs and when I bought my own E3631A (new), HP/Agilent/Keysight/whatever they're calling themselves this week revised the design and removed the rear chrome fan grill and went to one that was just stamped into the cover (aluminum enclosure --> steel). Also during this time Panasonic obsoleted their entire Panaflo line (for no good reason), forcing Agilent to go around and find a fan that had a similar blade design to stick in there, resulting in kind of an odd, protracted bait-and-switch. At least the supply did what I expected.
It was a noisy match made in hell. It wasn't even a *good* Chinese fan. WTF?
I tried out a couple of other fans in there and settled on a Papst because it wasn't running in stall and going turbulent like everything else. I can't remember the part number, but if I remember correctly I was going for something that was close to the original Panaflo or whatever they stuck in there in terms of specs.
The original cheap and nasty fan was killed in an appropriate manner. The little bastard didn't even have polarity protection. :)
Loved the video but maaan you need a new chair, it's loud.