I've got a bench top 12 volt power supply, which is putting out 13.7 volts. I am trying to power a 12 volt marine blower fan. When I power it up it won't spin unless I start it with my finger. The same fan on a 12 volt battery spins instantly.
What's going on? Is it an amperage issue? The power supply is supposedly rated to 9 amps, the fan draws 4 amps.
Last edited by Island_Moose; 22-10-2015 at 02:25 PM.
Island_Moose
aka John
Completed Builds:
FS-1G "Starcaster" Tribute - G.O.T.M October 2015
Current Build:
TL-1 "Indian Chief"
Hey Moose,
Weirdbits will have to answer this one but I'd guess the voltage and amps of the supply don't match the blower fan's requirements
Current Builds and status
scratch end grain pine tele - first clear coat on !
JBA-4 - assembled - final tweaks
Telemonster double scale tele - finish tobacco burst on body and sand neck
Completed builds
scratch oak.rose gum Jazzmaster - assembled needs setup
MK-2 Mosrite - assembled - play in
Ash tele with Baritone neck - neck pup wiring tweaks and play in
The bloody thing is integral to my spray booth project, which in turn has derailed my Shelby Daytona TL-1 hot rod Telecaster build.
Island_Moose
aka John
Completed Builds:
FS-1G "Starcaster" Tribute - G.O.T.M October 2015
Current Build:
TL-1 "Indian Chief"
yeah ok no one needs delays with a build. Have you got a spare 12 volt car battery you can use till the power supply issues are solved ?
Current Builds and status
scratch end grain pine tele - first clear coat on !
JBA-4 - assembled - final tweaks
Telemonster double scale tele - finish tobacco burst on body and sand neck
Completed builds
scratch oak.rose gum Jazzmaster - assembled needs setup
MK-2 Mosrite - assembled - play in
Ash tele with Baritone neck - neck pup wiring tweaks and play in
Hi Moose,
An electric motor can require a significant albeit brief spike in current to start.
So the battery is able to deliver this (as it is very short), on the other hand, the power supply may not be able to generate the current fast enough.
A solution to this is to put a big capacitor across the motor between it and the power supply.
An easier solution may be to float the battery on the power supply. In other word have the power supply connected in parallel to the battery and motor.
The power supply is then supplemented at start up by the battery and also charges the battery.
It is pretty much the same as putting a capacitor across, as batteries and capacitors are similar electrically.
Col.
I admit that I am an agent of Satan, however, my duties are largely ceremonial.
\m/
Kinda like this:
Col.
I admit that I am an agent of Satan, however, my duties are largely ceremonial.
\m/
Is the voltage reading, loaded or unloaded?
A power supply will have have a higher reading than if you just whack a meter across it.
13 volts is ok.
Put a 12 volt bulb across the out puts and then read the voltage.
If it's a lot lower than 12 you might need to re-Capp the supply?
Bruce
How old is the fan? It is designed to start spinning when voltage runs through the coils, but a build-up of dust/gunk in the bearings may be enough to prevent it from starting to spin.
Another thought, would it be better to use a brushless motor in the fan, in case there are any sparks between the armature and the brushes... ie spraying flammable substances into an ignition source?
Brushless fans are also just a better option IMO
Technically, the power supply should be able to power the blower fan with no problems, car batteries usually measure about 13V when fully-charged, the thing is, a car battery is capable of supplying at least 100 Amps when fully charged.
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