timsabre Posted February 18, 2012 Share Posted February 18, 2012 No heatsink? what type of LEDs are in this fixture, is it a small number (24 or 36) big ones, or a larger number of small LED's? If the fixture has a large number of small LEDs, you may well get away without using a fan for short periods as they don't get really hot like the high power ones do. Link to comment Share on other sites More sharing options...
boatman Posted February 18, 2012 Share Posted February 18, 2012 It's very easy to change the speed of a brushless DC motor by reducing the supply voltage. A low-dropout linear regulator (LM1117-ADJ) and a couple of resistors are all you need. Link to comment Share on other sites More sharing options...
bigclive Posted February 18, 2012 Share Posted February 18, 2012 Probably not. These fans have brushless motors and thus have integrated the electronics to drive said brushlessness, and generally sticking electronical stuff in series results in unequal sharing and thus one fan undervoltaged and the other overvoltaged, possibly to an unacceptable degree. And if that subsequently kill a fan fails then both'll stop and suddenly weve got no coling at all... Worse case scenario is at max the normal rated fan voltage. But you're right, there will be some intermodulation between the two fans because of the field switching. Easy to try... Link to comment Share on other sites More sharing options...
Keeper of the Keys Posted February 18, 2012 Share Posted February 18, 2012 With noisy computer fans cleaning the dust out and some wd40 often does wonders.... Link to comment Share on other sites More sharing options...
bigclive Posted February 19, 2012 Share Posted February 19, 2012 WD40 leaves a residue that holds dust and gums stuff up. Link to comment Share on other sites More sharing options...
Shakti Moon Posted January 12, 2018 Share Posted January 12, 2018 Good afternoon.I am new to this field and I am very, very old in this field.I am very old in this because I designed and ran lighting as early as 1973 in large houses in places like Vienna, Salzburg, Munich, Berlin, Hamburg, NYC, Chicago, LA, SFO, just to “drop” a few names. Those were the days of lots and lots of heat, gels, ladders, and actually the beginning of computers. I am new to this because I am now, for the first time, putting together a mobile lighting system on a shoestring budget. Which brings me to the subject of noisy fans. Having said “shoestring” I mean anywhere from free to cheap import, which forces me to discern the diff between professional pride pricing (male “I am good because my ‘stuff’ was expensive”) and substance. I experiment with cheap and see if I can make it work. I bought 4 54W cans and found them noisy. I undid the 6 small screws on the face, opened it up and unplugged the fan from the ICB, then retried and found none of it really hot. I will remove the fan itself to remove another air flow obstacle. Should work. Let me know what you think.Is there an option to find some (better?) replacement fans - I did this a while ago with some cheap LED cans, replaced the fans with 'silent' ones (which, whilst not silent, are a lot quieter than the original ones!) Link to comment Share on other sites More sharing options...
timsabre Posted January 12, 2018 Share Posted January 12, 2018 I think your leds will have a shorter life... Link to comment Share on other sites More sharing options...
alistermorton Posted January 13, 2018 Share Posted January 13, 2018 Yes, LEDs still need cooling. Replacing the noisy el cheapo fans with better, quieter fans is better than just removing them. Try Quiet PC USA (if, as I suspect, you're in Oregon) as a starting point. Link to comment Share on other sites More sharing options...
Chris Beesley Posted January 13, 2018 Share Posted January 13, 2018 "Gentle Typhoon" fans are quite cheap and actually very good for low noise cooling. Link to comment Share on other sites More sharing options...
graemeftv Posted January 13, 2018 Share Posted January 13, 2018 In a theatre environmentled parcans and movers controlled from DMX The Fan need almost never run, and needs to be thermostatically controlled. Massive advantage is gained over the the reduced amount of dust dragged into the fixture and the fan will out last everything else in the fixture! just think how many hours a fan will run every night before curtain up, when not a single led is on! most fixtures have a heatsink which is able to dissipate most of the heat if say just the red leds are on for one scene. (which is common for people to use only 1/3 of the leds at any one time) having encountered this problem we manufactured a basic pcb with just 3 components to control the fan speed dependent on temp. To confirm it is variable speed control not on/off. This is designed as a retro fit item for 12v or 24v fans. The pcb in 20mm x 20mm and can easy be added inside a parcan etc. Blueroom members are very welcome to have a free pcb! some significant time has been spent to design a very simple solution with few components and low cost to the noise problem. And ensure the leds dont overheat. inside our new designs the micro controller/ processor monitors the temp, and then controls the fan speed, (but not with pwm control to avoid motor wine!), a range of math checks are done by the microcontroller to compare number of leds on compared to temp, thus checking the fan is working and min fan speeds can be set dependent on number of leds on etc. Generally these issues come down to manufacturing cost, and sadly the people making the kit are not using it out in the field. Link to comment Share on other sites More sharing options...
Don Allen Posted January 14, 2018 Share Posted January 14, 2018 I recently silenced some Hosen RGBW COB's that had very noise fans bolted onto a heatsing with two long screws. The fans were mounted onto a steel plate which had the power supply mounted on the other side of the plate. Not an efficient design and a very noisy fan used. I used Jaycar Low Noise Fans that came with rubber mounting bushings. I had to make a new mounting plate to mount the fan on so it was not up against the mounting plate so air could be drawn past it, used four mounting points instead of 2 and used the rubber mountings which isolate fan noise. End result was you cannot hear the fan running from a meter away, definitely nothing audible when on a lighting bar. The airflow is slightly reduced, but I ran tests on the prototype using a no contact infrared themrmometer for several hours at full led output. These have been in service at several venues for multiple shows without any problems. Successful noise reduction appears to be the rubber mounts as the fans were audible when using screws as mounting. Link to comment Share on other sites More sharing options...
kaareolai Posted January 16, 2018 Share Posted January 16, 2018 ...I bought 4 54W cans and found them noisy. I undid the 6 small screws on the face, opened it up and unplugged the fan from the ICB, then retried and found none of it really hot. I will remove the fan itself to remove another air flow obstacle. Should work. Let me know what you think. I have quite many cheap led pars, and movingheads. I just put in (soldered, and crimped on isolation) a 5W resistor (2 in parallell also) in series with the fan. I measured the current, and computed ohms out of a voltage drop on around 10-15%. I found out on these cheap fans, if just you got them to go a tiny bit slower, that irritating sound pitch disappeared. Cooling down LEDs are essencial. On cheap LED PARs there are often only an alu plate. Putting on a heat sink make the need of a fast-running fan less. Or one might just exchange the fan with a better one... The best is, of coarse, to put in a temperature controlled fan pcb, of the kind to put into PCs in the 80-90ties. I have found one that runs fan slowly, and go to full above sat temperature. But these I intent more to put into expensivere MHs. Link to comment Share on other sites More sharing options...
DavePallant Posted February 8, 2019 Share Posted February 8, 2019 Fans can be noisy if they are mounted right up against a panel full of holes due to the blades being so close to the holes in the metal. You get a chopping noise from the blades and holes in close proximity. On some older pars I have bought the fans are right against the case and then just outside the fan vents the locking disc for the mount also partially blocks the fan so there is noise that interference with the air flow as well. You can mount the fans off of the case - which is where rubber mounts might help - to space the fan blades from the edges of the holes but you will also need to ensure that the fan cant leak back into the case. Any material used to 'duct' the fan has to be non flammable of course! Link to comment Share on other sites More sharing options...
OddSocks Posted February 12, 2019 Share Posted February 12, 2019 I had some Cheep Pars and found that slowing the fan caused them to intermittently loose the white segment of the RGBWA changing the colour output. This only happened if all the segments were on full for a while.I then created some ducting to direct the air flow and this helped. The original fan was placed so that it was just moving the air around, not actually getting fresh from outside. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.