Carver PM1200 Amplifier Series Fan Motors...

Hello all... Looking for any assistance from the obviously wise group at this site... I need to try to source "at reasonable cost" the Mabuchi Fan motors for Carver PM 1201 (circa 1993-94) Series Pro amplifiers (2 req'd per amp)... Way to much $$ last cost thru local sources!!

Appreciate any leads you can give here; require 12 pcs. minimum at this time, more to follow. Thank you in advance; bob
 
If they use the same ones as an old Carver amp that I have, then they are the typical small crappy motors as they are used for battery driven toys.
If one wants to use a nice modern fan then he has to more mechanical work than just changing a fan unfortunately.

Small motors like that can sometimes be found as surplus.

Regards

Charles
 

tlparker

Member
2006-05-08 5:19 am
using new fan for carver pm 350

Got a Carver pm 350 with screeching motor. Bending metal on sides helps/hurts, but I could see sparks in motor so knew things weren't good.

Took fan out. Motor is "Mabuchi" and with small flat-cap across back two leads. Looks like really cheap crummy motors compared to today's cooling motors, so I'm hoping to replace it with something better. Anybody know where I can get spec for this motor or enough info from something like wiring diagram to be abel to find replacement? This thing is like little heavy toy motor that you'd use to run a cheap car around with. Gotta be better way.
 
Stupid Fan Stuff....

The screeching would undoubtedly be the Armature rubbing against the Brush arms (?) which means the end is near.... Had some luck on a couple of Surplus suppliers, but still would use more if I could get them... should be $5.00 ea if you get a deal...

Original ones were in amps for 5 years of reasonable usage (Pro Audio) before gone bad, so cost is not unreasonable for the product usage!! Will post/ send any info if I find a "motherload" of these.... Take care all; bw
 

tlparker

Member
2006-05-08 5:19 am
nope, not the motor itself (entirely)

While part of the problem is the fan blades grinding against the case (which is "finned" in this area to allow air flow) and that this is caused party by the armature being weak in its holdings, but also moves in/out slightly (mm's) dependent upon current flow, creates a very real motor issue.

I have already removed the motor. It is a piece of junk, similar to that used in a child's toy. If I could find a similar AC motor (like all the wonderful DC ones we now have) it would be a simple replacement. There is a CAP across the terminals which appears there solely to adjust the fan's speed in relation to the input voltate (and thus amp drawage in the case of this product).

Would love to hear realistitc solutions.
 

birdyman

Member
2010-01-15 2:28 pm
I am not sure how closeCaver PM1.5 and Caver pm 1200 are in their layout. I modified my PM1.5s by using 12v dc computer fans with ball bearings. Better CFM less noise. I made 7v for low speed and 12v for full speed, IIRC. I think a guy at the TheCarversite.com has original fans for sale if you like that toy fans.
 

birdyman

Member
2010-01-15 2:28 pm
Here is what I did to my PM1.5. I used left over power NPN and took out most of parts from fan board and used surplus Computer fan motor.
forums


PS: I don't think image is working. What do you put in for URL of image?
 
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birdyman

Member
2010-01-15 2:28 pm
I gave up on uploading image. Basically, I used transistor (left over power NPN type) and 7.5 zener and 12 zener to control the voltage. Supply voltage as it is wired originally is about 25v or so. You need to put filter cap of 300 t0 500uf 50v to smooth out ripples. then make a close copy of PM1.5s 12 supply circuit for + side only. You can find schematic at www.thecarversite.com. Good luck
 

vcovca

Member
2013-04-19 1:33 am
Whahahah: Typical Applications : Home Appliances > Massager / Vibrator

Well, I'm on a mission to.. got three PM1201's here. All fans blown, one fan board burned. There is one more Carver in the venue, a bigger one. Also out of order.

If anyone could help... the fans are useless. I'm planning on overhauling the fan part :) If I'm correct the motors get 48V AC, but are in series. Can I take the whole fan board out??
 
The fans are the type used in model racing cars. I think they're rated at 18V with a series 1 Ohm 7W resistor (in the PM1.5, single fan).
One of the design flaws is that the motor can burn out before the resistor if the amp is run at max level for a long period.
As standard, I put a 3W 24V zener across the fan motor to give it a break
 
Carver fan question

To those of you who have a Carver PM- Series amplifier, does the fan always run? Or just when it gets hot?

I just got a PM-900 amp off ebay, and the fan does not turn on, nor does it get any voltage to the fan leads....but the amp operates just fine thus far. Aiming an infrared thermometer at the heatsink gives a temp of about 15 degrees above ambient. I have it driving a pair of 4ohm 15" subs wired in series so the amp sees 8ohms.

This is my first post on here, thanks in advance for your help.