Question for the electrician/electrical engineer: Whirlwind fan conversion

shardian

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Question for the electrician/electrical engineer: Whirlwind fan conversion

Here's the problem:
The Whirlwind topper uses a Triac driver board which feeds 24vac to a custom made fan. this fan motor is no longer available and Marco Specialties may or may not find a vendor willing to make it.

I've done a bit of research on this, but my lack of detailed electrical knowledge is a hanging point.

In HVAC systems, it is common to use 24vac thermostats to drive 120VAC blower motors using a relay. So....is there any reason that can't that be used here? 120vac C-frame motors and fan blades with the same specs as the OEM 24 volt whirlwind fan are readily available.

If someone were able to come up with an affordable retrofit kit on this front, I'm sure more than a few units could be sold.

So, anyone with ample electrical skillz wanna pitch in?
 
Just connect a heavy duty 24 volt AC relay to the original connections that went to the fan motor. The triac will turn on the relay. From there you could find a source of 120 volts ac in the cabinet (like the service outlet for instance) and feed the power to the switched contacts of the relay. Very simple.

Too small of a relay may not get turned on by the triac as the load might be too small.

Suggested relays:

NTE R02-5A10-24 (8 pin octal plug in base) with socket # R95-101

NTE R10-5A10-24 (.187 quick connect 11 pin blade terminal plug in base) with socket # R95-105

NTE R14-5A15-24 (8 pin .187 quick connect blade terminal base) with socket # R95-110

NTE R12-11A5-24 (ice cube style) with socket # R95-106A
 
Last edited:
Sounds simple enough. I just can't wrap my head around why they made the original that way in the first place.

Admiral Ackbar keeps whispering in my ear about some sort of trap...;)
 
You know, you were just in my office. I could have walked across the hall and got you an Electrical Engineer.

I had an email in with an EE I used to talk with, but he went MIA about a year ago. I never thought to ask the Aker guys. I don't really know any of them. If any of them are interested in vids and pins, feel free to get them in the loop!
 
Here's the problem:
The Whirlwind topper uses a Triac driver board which feeds 24vac to a custom made fan. this fan motor is no longer available and Marco Specialties may or may not find a vendor willing to make it.

I've done a bit of research on this, but my lack of detailed electrical knowledge is a hanging point.

In HVAC systems, it is common to use 24vac thermostats to drive 120VAC blower motors using a relay. So....is there any reason that can't that be used here? 120vac C-frame motors and fan blades with the same specs as the OEM 24 volt whirlwind fan are readily available.

If someone were able to come up with an affordable retrofit kit on this front, I'm sure more than a few units could be sold.

So, anyone with ample electrical skillz wanna pitch in?

I see no reason you couldn't replace the Triac PCB with a 24V relay and drive whatever fan you want at whatever voltage you want.

Maybe I'm missing something but this is a pretty simple concept.
 
I got a PM from him and he said it worked out perfectly.

So folks should keep this mod in mind if they have the fan motor go bad or if the fan topper is missing.
 
This is a copy/paste from a rec.games.pinball USENET post on this very subject Dated Jan 19-20, 2011.

NOT MINE.

Okay, here is my rough draft on the procedure. Note that it is
possible that this motor will work with the existing mounting bracket.
I have no way to confirm though.

SUPPLIES
Motor: http://www.grainger.com/Grainger/DAYTON-CFrame-Motor-4M073
Relay: http://www.grainger.com/Grainger/STEVECO-Enclosed-Fan-Relay-4E658
Fan Blade: http://www.grainger.com/Grainger/DAYTON-Propeller-5JLN4
power cord: Wal- Mart 15 foot polarized 2 prong extension cord ($3)


Triac cable (if needed):
-7 pin .156 molex housing (or trim down larger)
- (4) 2' sections of purple wire (to match original harness)
- (4) .156 trifurcon molex pins
- 2 insulated 1/4" female quick disconnect crimp on wire terminations


Misc other stuff:
- extension wire for fan
- wire nuts (or solder and shrink wrap)
- 2 additional insulated 1/4" female quick disconnect crimp on wire
terminations
- Material to make fan mount (1/2" or 5/8" aluminum stock from
hardware store
- mounting screws
- 1/4" Lock nuts


BASIC Theory:
The Triac board outputs 26vac to power a custom fan in the topper. Why
Williams used such a non-standard item, I have no clue. Luckily, 24vac
is quite a common voltage in the HVAC industry. 24vac is used as the
control voltage in 120vac HVAC blower motor relay systems. 24vac is
close enough for our means since we have no actual load - We are
merely energizing the relay coil. So...what we want to do is use a
common off the shelf 120vac fan motor that has identical output specs
as the original Whirlwind fan, and use the Triac boards output merely
to control the 'on/off' function of our motor. Pretty cool huh? I
guess all those Circuits classes in Engineering school were worth
something after all!


Wiring:
First, determine where you will mount relay. I chose the right inside
wall of head. You may prefer right next to the triac. Personally, I
like to terminate the 120v as soon as I get in the head and keep it
off to the side out of the way.


The relay has your basic wiring diagram on the side. Here's the
"common sense approach":
- cut off female end of extension cord. Cut approx 4-5 feet off of
cord to make it about 8-9 feet long. Make sure to tag the 'hot' and
'common' leads (verify with DMM - small prong on plug is hot). Cut
and terminate 'hot' wire to tie into the 'hot' pin of the relay. Leave
'common' power wire longer so it can run up to the fan motor. Connect
'common' power wire to one of the fan motor wires - doesn't matter
which - using preferred method (solder/shrink tube, wire nuts,
disconnecting end terminals, 2 pin molex connector, etc, etc.). Attach
additional wire to other fan motor lead and run it back to the
'ground' pin of the relay. Why do it this way? Because the service
outlet is always hot. You want to make sure you terminate the hot wire
at the relay, that way the fan never has power unless it is actually
running.


If you have a triac fan wiring harness, modify if necessary and run
the 2 leads to the relay 'coil' lugs. If no harness, use materials
listed above to make the harness as described in the triac schematic
in the game manual.
2 wires in pins 1 and 2 tied together at other end with Quick
disconnect
2 wires in pins 4 and 5 tied together at other end with Quick
disconnect
Might as well order a molex key to 'dummy proof' your harness as well.


Plug the power wire into the service outlet inside the game. If you
wanna get real fancy, you can splice it into the machine's power cord
(after the power switch, but before the power board).


FAN SETUP: (I don't have a finalized motor mount yet. I have handed
over my machine to a friend for a shop job since I am tight on time
now. He will finish the mount. I have enough guidance for you to
finish it though.)


First off, take out the mounting screws and flip them around. Then put
a lock nut on each screw to secure the motor. Take your measurements
to place the fan shaft at the center of the screen cutout. Cut the
aluminum stock to match your measurements (one bracket to each bolt on
the motor), and allow some area to mount to backbox after you bend it
into a bracket. Drill holes to match the mounting locations for the
motor and the backbox screws. Bend the mounts so that the fan angles
the same as the topper.


Attach the fan blade by merely pressing it on. You may notice this fan
blade is different than stock. There is a reason for that - the stock
fan blade sucks! I have one in there now and it barely blows on you at
only 50 CFM's. This bad boy is more aggressive and blows a manly 200
CFM's.


If you simply must have the stock blade look, Grainger has it but the
mounting hole is 1/4 instead of 3/16. You have to tape build-up the
shaft to get it to stay on.


So there you go. It isn't a whole lot of work to do it yourself, but
as I've learned, alot of pin folks don't like doing the menial tasks.
I've switched over to that side myself because I just want to play! If
you'd prefer a kit where you just have to screw it in and connect a
few connectors, then I'll set you up with my friend that I have handed
my Whirlwind off to for shop-out.
 
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