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Organ project

jdmoo

New Member
Hi all

I'm building a small experimental drone organ: only 4 to 5 pipes. Similar to this one
I'm more a musician, then a electronics wizzard. To be fair, a real beginner.

For the air supply, I'd like to use this fan.

What kind of supply would I need to get this working?
Would this one work?

Next to that: there is a possibility to control the speed of the fan by PWM. Can anyone tell me how to? Maybe draw a schematics ...

Thanks for the help!!
Jan
 

rjenkinsgb

Well-Known Member
Most Helpful Member
That PSU should be fine.

It's probably cheaper to get a ready made PWM module that build one - just search ebay or amazon for 24V DC PWM

eg.
 

JimB

Super Moderator
Most Helpful Member
What kind of supply would I need to get this working?
Would this one work?
Yes that looks OK.

there is a possibility to control the speed of the fan by PWM. Can anyone tell me how to? Maybe draw a schematics
Yes, that is not a problem, look at page number 577* of this document:

* The linked document is not 577+ pages long, it is a 15 page extract from a larger document.

As for a schematic for implementing PWM, please excuse me but I am otherwise busy at the moment so I cannot devote time to it, sorry.

JimB
 

JimB

Super Moderator
Most Helpful Member
It's probably cheaper to get a ready made PWM module that build one - just search ebay or amazon for 24V DC PWM
Please note that the fan has a PWM controller built in, it just needs an external open collector PWM signal on the Control wire into the body of the fan.

JimB
 

jdmoo

New Member
Thanks!!
Could you show me an example of 'an external open collector PWM signal'? Or are these the ones rjenkinsgb is referring to (see above)?
 

JimB

Super Moderator
Most Helpful Member
OK, I finished off my "other stuff" and had some electronic playtime.

Have a look at this schematic:
LM555 PWM.png

It uses a 555 timer to create a PWM signal at pin 3 of the 555.
That signal drives the base of the 2N3904, and out of the collector of the '3904 we have an "open collector PWM signal" which can connect to the brown wire of the fan and will adjust the speed of the fan.

Power for this circuit can come from the 24v PSU which drives the fan, but to reduce the 24v down to something which the 555 can tolerate, there is a 7812 voltage regulator.

To test this, I lashed up the 555 and associated timing components on a breadboard, and looking at the output of the 555 (pin 3) on the oscilloscope I saw this:
PWM 1.JPG
With the 10k pot at one end of its travel there was a pulse train with a 10% duty cycle.

Turning the 10k pot to nearly the other end of its travel:
PWM 2.JPG

An 86% duty cycle pulse train.

With the 10k pot at the end of its travel:
PWM 3.JPG

A 99% duty cycle, but the frequency has shifted from 25kHz to 18kHz, not really a problem, but that is simple 555 circuits for you.

So, as an electronics beginner, will this do what you want?
ps, I am no musician, practically tone deaf.

JimB
 

jdmoo

New Member
Hi all,

I ordered the fan (Sanyo Denki 9BMB24P2K01) and the power suplly (mean well RS 50-24).
Apparently, I need to regulate the outcoming voltage.
This is the datasheet of the fan:
datasheet san ace.JPG
If I'm correct, it should be 22,7? (50 w / 2,2 A = 22,7 V)

I'm all new to this, that's why I ask first before connecting these things.

Thank you all!
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Hi all,

I ordered the fan (Sanyo Denki 9BMB24P2K01) and the power suplly (mean well RS 50-24).
Apparently, I need to regulate the outcoming voltage.
This is the datasheet of the fan:
View attachment 131117
If I'm correct, it should be 22,7? (50 w / 2,2 A = 22,7 V)
No, it's a 24V fan, you supply 24V to it - which isn't terribly critical, as shown in the specs.
 

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