Micro electronics help, converting 9 volt fast FedS motors to standard speed 12 volt?

[rwo978]

When it comes to 12 volt electrical, I understand the whole pos/neg, relays, and diodes.... But as far as capacitors, resistors.... I'm lost.


So, the dual speed Firebeams use 9 volt motors with a switch and a X/resistor??? Correct? To slow the speed down?? What would I need to convert a 9 vt motor in a stand alone beacon to 12 volts?

 

[chief1562]

When it comes to 12 volt electrical, I understand the whole pos/neg, relays, and diodes.... But as far as capacitors, resistors.... I'm lost.

So, the dual speed Firebeams use 9 volt motors with a switch and a X/resistor??? Correct? To slow the speed down?? What would I need to convert a 9 vt motor in a stand alone beacon to 12 volts?

Ryan,


You still need more 12's I gots them how many more you need.

 

[rwo978]

Well, on another note, I kindof half wanted to figure out how to put the switch into a beacon, like the FB3, and make it switchable.

 

[chief1562]

I'm gussing you already have a firebeam for reference.


Or you could always get a variable control like on a volume switch and ue it has a dimmer switch.


Should do what you want to do.


They make'm small enough to fit in there.

 

[MtnMan]

I don't have one to look at, but it should just be a SPDT switch. Fast position sends +12V direct to the motor. Slow position goes through a resistor.

 

[rwo978]

OK, did some measuring with the multi meter on an FB3, and some research on the net as to Ohms... @ 12 volts, the FB3 is running about 12.2 volts. @ '9' volts, it's running about 7.5. Thru the resistor, the reading was 57. There's print on the resistor that states 'CRC 50 ohms'. So, am I understanding that I need a 50 ohm resistor? Is it bad that it's 'overdriven', coming out at 57 across each end vs 50?

 

[chief1562]

Nope DPDT. There are 6 conections to the board.


Here's what's left of mine. And this thing is not easy to find.


I have a couple of emails out to different companies FS no longer makes them.


Measurement are in " & mm has followes 0.6325 (16.06mm)L x 0.4045 (10.28mm)W x 0.306 (7.78mm)D


And I've checked Ebay most give measurements. Tryed RadioShack. Local electronics stores.


As usual these manufactures make stuff you can only get from them. And when the stuff is discontinued you can't find parts.


Part Number Switch, DPDT K122276A

 

[rwo978]

The switch is easy enough to find. But, what about the thing by the arrow. That's the main thing I believe I need.

 

[MtnMan]

Is there a wattage marking on the resistor? If not, 1 or 2 W should be fine.


I'd suggest getting a pack of these: 100 ohm 1W 5% Metal-Oxide Film Resistor (2-Pack) | RadioShack.com. Put the two in parallel to make 50 Ohms. And don't sweat plus or minus a few Ohms. Considering that supply voltage could be anywhere from 12-15 V, this isn't brain surgery.

 

[rwo978]

What does the watt have to do with resistors?

 

[chief1562]

The switch is easy enough to find. But, what about the thing by the arrow. That's the main thing I believe I need.

View attachment 69496

let me see what I can come up with.


if you can find a switch that will fit let me know.


remember it sits sides ways.


i was thinking if I could find one small enough and it didn't sit sideways I'd run leds to each contact point.

 

[chief1562]

Here's the parts list and id numbers. http://www.federalsignaldistribution.com/docs/visual/pdfs/FB3SM.pdf


Just says PCB board.


Looked at mine it has the follwing on it DALE RS-2B 50ohm 1% 9043.

 

[MtnMan]

What does the watt have to do with resistors?

The watt rating is how much power (i.e., heat) the resistor can dissipate without burning up.


According to the measurements you provided:


Voltage drop through the resistor = 12.2 - 7.5 = 4.7 Volt


Current through the resistor = 4.7 Volt / 57 Ohm = 0.08 Amp


Power dissipation = 4.7 Volt x 0.08 Amp = 0.4 Watt


A 1/2 W resistor would be a bit too close for comfort, but 1 W or higher will work.

 

[chief1562]

The watt rating is how much power (i.e., heat) the resistor can dissipate without burning up.

According to the measurements you provided:


Voltage drop through the resistor = 12.2 - 7.5 = 4.7 Volt


Current through the resistor = 4.7 Volt / 57 Ohm = 0.08 Amp


Power dissipation = 4.7 Volt x 0.08 Amp = 0.4 Watt


A 1/2 W resistor would be a bit too close for comfort, but 1 W or higher will work.

So what you trying to say in the info on mine is wrong?


And i tested mine with a ohm meter and it show 50 ohms just like it's written on the resistor

 

[rwo978]

The watt rating is how much power (i.e., heat) the resistor can dissipate without burning up.

According to the measurements you provided:


Voltage drop through the resistor = 12.2 - 7.5 = 4.7 Volt


Current through the resistor = 4.7 Volt / 57 Ohm = 0.08 Amp


Power dissipation = 4.7 Volt x 0.08 Amp = 0.4 Watt


A 1/2 W resistor would be a bit too close for comfort, but 1 W or higher will work.

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Someone did the calculations!!! So, a 1 watt, 50-60 Ohm resistor would work?

 

[chief1562]

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Someone did the calculations!!! So, a 1 watt, 50-60 Ohm resistor would work?

Ryan,


Can you get me a switch to fit mine?


The same resistor that is in ours seems suffice for what is intended to do.

 

[rwo978]

What I'm actually looking to do is possibly wire a SPDT micro switch onto the bottom of a FedSig 100 beacon, X 2, and mount them on a crossbar. Or, I may just wire the resistor inline.


As for that actual slider switch on an FB3, I don't think I'd use those.

 

[MtnMan]

So what you trying to say in the info on mine is wrong?
And i tested mine with a ohm meter and it show 50 ohms just like it's written on the resistor

If it's marked 50 Ohms, that what it should be. I used Ryan's measured value of 57 for the math, but it's no big deal either way.

 

[MtnMan]

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Someone did the calculations!!! So, a 1 watt, 50-60 Ohm resistor would work?

Correct. Test for excessive heat to be sure.

 

[chief1562]

What I'm actually looking to do is possibly wire a SPDT micro switch onto the bottom of a FedSig 100 beacon, X 2, and mount them on a crossbar. Or, I may just wire the resistor inline.

As for that actual slider switch on an FB3, I don't think I'd use those.

Suggestions on what to replace mine then.


Mine all it does now is the light comes on and that's it.

 

[rwo978]

Suggestions on what to replace mine then.
Mine all it does now is the light comes on and that's it.

Not sure of the amp rating required, but would this work?


12VDC 0.1A DPDT Right-Angle PCB Mount Slide Switch : Slide Switches | RadioShack.com

 

[rwo978]

Or, here's some on eBay.


DPDT Right-Angle Slide Switch | eBay

 

[chief1562]

Thanks Ryan


But I found a switch in my junk stuff I've collected. Got it working today.It wasn't right angle it was a straight chassiss type but got the job done.


When I finish the rebuild on the UF7 will most all in Tip & Tricks.

 

[rwo978]

I got this to work with a SPDT switch and a resistor. Model 100 beacon shown. Made 2, going to mount them on another crossbar.

 

[chief1562]

I got this to work with a SPDT switch and a resistor. Model 100 beacon shown. Made 2, going to mount them on another crossbar.

View attachment 69833View attachment 69836View attachment 69837

Nice job and I thought the wiring on my Firebeam switch was small to work with.