Rembrant's new non-Bullnose project

[ArdWrknTrk]

Cory's questions are very interesting. Jim and Gary, what about the switch position?

There is no specification about the output it delivers, no more about the voltage it is built for. Just a precision about 10amp rating.

Do we have to assume it is a "normal" 12V vehicle switch?

If so, I am curious about how its position in the circuit will affect the result. It is not a simple on/off switch, since it delivers low and high "speeds" to the blower. Which current (V? A?) will it deliver if placed before or after the voltage reducer? What will be the final "low and high" output to the fan?

Another question Cory has is the ground strategy. I never questioned myself about this, but I always assumed a car body is a 12V electrical circuit, an extension of its negative battery pole. But Cory made me realize that I could probably make different electrical current (6V, 12V, 120V, 240V) to transit by a same unique metal "ground" piece, and close their own circuit with their own positive pole?

You're referencing to ground in a DC circuit.

If the voltage regulator is claimed by the manufacturer to have no isolation and that both grounds can be bonded, then it makes sense that they both go to chassis.

Having an independent ground -out- is a way to tie an isolated load back to that ground (as would be the case of a motor or other load mounted on plastic)

The switch is 4 position (off, low, medium, high) and appears to be a simple resistor array. (given its ceramic housing)

Obviously off is open circuit and High is close to zero ohms. I couldn't say what 'Low' and 'Medium' are with this switch, but I could tell you what the various ohms (speeds) are for a Ford resistor block.

....Much like the ceramic housing wire-wound potentiometer attached to the back of our headlamp switches that don't have any forced air flow to cool them.

The 6V voltage regulator Cory linked says: 9-35V input and 10A @ 6V (60W) output with: over current, over load, over voltage, over temperature and short circuit protection; auto recovery when device is back to normal operating (parameters)

I expect a simple IC driving a mosfet or other power transistor that requires the aluminum housing to dissipate its losses.

You can't use a transformer with DC, it doesn't work that way.....

 

[BigBrother-84]

You're referencing to ground in a DC circuit.

If the voltage regulator is claimed by the manufacturer to have no isolation and that both grounds can be bonded, then it makes sense that they both go to chassis.

Having an independent ground -out- is a way to tie an isolated load back to that ground (as would be the case of a motor or other load mounted on plastic)

The switch is 4 position (off, low, medium, high) and appears to be a simple resistor array. (given its ceramic housing)

Obviously off is open circuit and High is close to zero ohms. I couldn't say what 'Low' and 'Medium' are with this switch, but I could tell you what the various ohms (speeds) are for a Ford resistor block.

....Much like the ceramic housing wire-wound potentiometer attached to the back of our headlamp switches that don't have any forced air flow to cool them.

The 6V voltage regulator Cory linked says: 9-35V input and 10A @ 6V (60W) output with: over current, over load, over voltage, over temperature and short circuit protection; auto recovery when device is back to normal operating (parameters)

I expect a simple IC driving a mosfet or other power transistor that requires the aluminum housing to dissipate its losses.

You can't use a transformer with DC, it doesn't work that way.....

Okay... I am almost a complete dummy in electrical questions... Understand by "almost" that I can run wires (ac or dc), install breakers, switches (regular and 3-ways), lights, heating, outlets, the moment it stays simple.

But at the moment you add a resistor in a circuit, or any electronic widgets, I'm lost.

Now let's get back to Cory's fan switch position in the circuit. I'll use a metaphorical image to explain what's no clear for me (let's assume all DC).

Correct me if I am wrong:

• If I put a 12V bulb in a 120V circuit, it will blow out.

• Reversely, a 120V bulb in a 12V circuit represents a too high resistance, it will glow very yellow (if it glows...).

So, if Cory's switch is made for a 12V input, but is placed between the voltage reducer and the blower, I suspect its ohms resistance (built to receive 12V input) will be too high, so the output won't be enough to turn the blower at the good speed. I suppose...

The same way, if this switch is placed before the voltage reducer, is it possible that this reducer will to much lower the power delivered to the blower?

In other words, can a "dimmer switch" be placed in a circuit regardless of the voltage of this latter? I suspect no...

Thanks for your patience gentlemen!

And Cory, I apologize hacking your thread this way! But your questions are very interesting!

[ArdWrknTrk]

Okay... I am almost a complete dummy in electrical questions... Understand by "almost" that I can run wires (ac or dc), install breakers, switches (regular and 3-ways), lights, heating, outlets, the moment it stays simple.

But at the moment you add a resistor in a circuit, or any electronic widgets, I'm lost.

Now let's get back to Cory's fan switch position in the circuit. I'll use a metaphorical image to explain what's no clear for me (let's assume all DC).

Correct me if I am wrong:

• If I put a 12V bulb in a 120V circuit, it will blow out.

• Reversely, a 120V bulb in a 12V circuit represents a too high resistance, it will glow very yellow (if it glows...).

So, if Cory's switch is made for a 12V input, but is placed between the voltage reducer and the blower, I suspect its ohms resistance (built to receive 12V input) will be too high, so the output won't be enough to turn the blower at the good speed. I suppose...

The same way, if this switch is placed before the voltage reducer, is it possible that this reducer will to much lower the power delivered to the blower?

In other words, can a "dimmer switch" be placed in a circuit regardless of the voltage of this latter? I suspect no...

Thanks for your patience gentlemen!

And Cory, I apologize hacking your thread this way! But your questions are very interesting!

Nope.

Ohms law V/IR

The resistor has to be rated enough watts (dissipation) to handle what is drawn through it. It doesn't care about voltage or amperage (except at whatever point it's insulation breaks down)

In this case the speed control is rated for 10A and the fan motor draws 10A, the regulator has a rated output of 10A @6V as well.

10A @ 6V is 60 watts.

5A @ 12V is 60 watts

0.5A @ 120V is 60 watts

0.1A @ 600V is 60 watts

This is a big reason that BEV's and grid storage batteries are usually relatively high voltage (6-800V in most current cars)

If you want to speak about AC, look at transmission lines or what voltage industrial equipment runs at.

Smaller cables and motor windings can push the same amount of power (watts) because amperage is the big factor in heating the conductor.

 

[Gary Lewis]

Okay... I am almost a complete dummy in electrical questions... Understand by "almost" that I can run wires (ac or dc), install breakers, switches (regular and 3-ways), lights, heating, outlets, the moment it stays simple.

But at the moment you add a resistor in a circuit, or any electronic widgets, I'm lost.

Now let's get back to Cory's fan switch position in the circuit. I'll use a metaphorical image to explain what's no clear for me (let's assume all DC).

Correct me if I am wrong:

• If I put a 12V bulb in a 120V circuit, it will blow out.

• Reversely, a 120V bulb in a 12V circuit represents a too high resistance, it will glow very yellow (if it glows...).

So, if Cory's switch is made for a 12V input, but is placed between the voltage reducer and the blower, I suspect its ohms resistance (built to receive 12V input) will be too high, so the output won't be enough to turn the blower at the good speed. I suppose...

The same way, if this switch is placed before the voltage reducer, is it possible that this reducer will to much lower the power delivered to the blower?

In other words, can a "dimmer switch" be placed in a circuit regardless of the voltage of this latter? I suspect no...

Thanks for your patience gentlemen!

And Cory, I apologize hacking your thread this way! But your questions are very interesting!

The switch/resistor is generic in that while it may have been envisioned for a 12V circuit the designers had no way of knowing what motor it would be used with. So placing the switch/resistor in the 6V circuit with a motor that only pulls 10A will probably give the same results as using it in a 12V circuit and a motor that pulls 20A.

But as Jim pointed out, placing it in the 12V circuit ahead of the voltage regulator could easily cause the regulator to quit working as the input voltage gets down close to 6V. However, above that point the fan will still be running at full speed because it is being fed a full 6V. In other words, it won’t work correctly ahead of the regulator.

[ArdWrknTrk]

The switch/resistor is generic in that while it may have been envisioned for a 12V circuit the designers had no way of knowing what motor it would be used with. So placing the switch/resistor in the 6V circuit with a motor that only pulls 10A will probably give the same results as using it in a 12V circuit and a motor that pulls 20A.

But as Jim pointed out, placing it in the 12V circuit ahead of the voltage regulator could easily cause the regulator to quit working as the input voltage gets down close to 6V. However, above that point the fan will still be running at full speed because it is being fed a full 6V. In other words, it won’t work correctly ahead of the regulator.

The regulator is electronic, not linear.

It will provide 6V out from 35v in all the way down to 9V input.

At that point it is 'out of parameters' and the regulator will shut down.... as I pointed out above.

[Rembrant]

The switch/resistor is generic in that while it may have been envisioned for a 12V circuit the designers had no way of knowing what motor it would be used with. So placing the switch/resistor in the 6V circuit with a motor that only pulls 10A will probably give the same results as using it in a 12V circuit and a motor that pulls 20A.

But as Jim pointed out, placing it in the 12V circuit ahead of the voltage regulator could easily cause the regulator to quit working as the input voltage gets down close to 6V. However, above that point the fan will still be running at full speed because it is being fed a full 6V. In other words, it won’t work correctly ahead of the regulator.

Thank you gentlemen for all of the detailed answers. I knew that you guys would know what to do. Thanks for always being so helpful. Wiring this truck from scratch is going to be a bit of a task, but for the most part it will basically be wired up as an 80's pickup with a Duraspark ignition, a 3G alternator conversion and a Quick4 transmission controller, so if I run into any snags, I know where to go for help! Thanks again.

So placing the switch/resistor in the 6V circuit with a motor that only pulls 10A will probably give the same results as using it in a 12V circuit and a motor that pulls 20A.

Interesting point you make here Gary, and one I have to ask about out of curiosity. In my searches for information on this blower fan, I found a lengthy discussion on another forum a few weeks ago (Jalopy Journal, I think) where they were going over the options for running this 6v motor in a 12v system.

Apparently some guys just run the motors at 12v. Since these are mostly fair weathered vehicles these days, I doubt anybody runs the heaters very often. The argument was over the amperage. Quite a few people said that if you run the 6v motor with 12v that it will only draw half the amps the motor would draw with 6v. The other half of the people said no way, that it would not only draw the same 10amps the 6v would draw, but that it would draw much more than the 6v.

Anyway, I couldn't find much of an answer at the end of any of these debates, so I just said screw it, I'll run the motor at 6v and not worry about it.

If you're around old cars and trucks or even car shows, etc any length of time, one thing you'll notice is a fairly common occurrence: Fires. I don't want to contribute to that, so I'll try to do the "right thing" wherever possible (and I have a high tolerance for the wrong things by the way...lol).

PS: My brother in law suggested taking the motor to a motor shop and see if they would convert it to 12v for me. It said that it should be fairly simple. I think he said just remove one set of brushes and voila, it's a 6v motor.

 

[Gary Lewis]

Thank you gentlemen for all of the detailed answers. I knew that you guys would know what to do. Thanks for always being so helpful. Wiring this truck from scratch is going to be a bit of a task, but for the most part it will basically be wired up as an 80's pickup with a Duraspark ignition, a 3G alternator conversion and a Quick4 transmission controller, so if I run into any snags, I know where to go for help! Thanks again.

So placing the switch/resistor in the 6V circuit with a motor that only pulls 10A will probably give the same results as using it in a 12V circuit and a motor that pulls 20A.

Interesting point you make here Gary, and one I have to ask about out of curiosity. In my searches for information on this blower fan, I found a lengthy discussion on another forum a few weeks ago (Jalopy Journal, I think) where they were going over the options for running this 6v motor in a 12v system.

Apparently some guys just run the motors at 12v. Since these are mostly fair weathered vehicles these days, I doubt anybody runs the heaters very often. The argument was over the amperage. Quite a few people said that if you run the 6v motor with 12v that it will only draw half the amps the motor would draw with 6v. The other half of the people said no way, that it would not only draw the same 10amps the 6v would draw, but that it would draw much more than the 6v.

Anyway, I couldn't find much of an answer at the end of any of these debates, so I just said screw it, I'll run the motor at 6v and not worry about it.

If you're around old cars and trucks or even car shows, etc any length of time, one thing you'll notice is a fairly common occurrence: Fires. I don't want to contribute to that, so I'll try to do the "right thing" wherever possible (and I have a high tolerance for the wrong things by the way...lol).

PS: My brother in law suggested taking the motor to a motor shop and see if they would convert it to 12v for me. It said that it should be fairly simple. I think he said just remove one set of brushes and voila, it's a 6v motor.

Regarding the motor's voltage, the no-load speed doubles if you double the voltage - assuming the windings don't separate from the armature. Or, if you double the voltage and the load stays the same the current is cut in half. The problem is that we don't know what the load does as the speed of the motor increases.

But it is pretty safe to assume that as the speed goes up so does the load. With some fans doubling the speed increases the load by a factor of 4. In some you may cause cavitation and there will be little if any flow. So it isn't true that with twice the voltage the current goes down to half.

As for rewiring the motor, I wish removing a set of brushes would do it. But since most motors with brushes only have two, removing one set would cut the current and the speed significantly.

Seriously though, I called around a year or so ago looking for someone that would rewind a Bullnose blower motor to give more air movement. No one would touch it, with one guy saying it would cost "hundreds of dollars".

 

[BigBrother-84]

Regarding the motor's voltage, the no-load speed doubles if you double the voltage - assuming the windings don't separate from the armature. Or, if you double the voltage and the load stays the same the current is cut in half. The problem is that we don't know what the load does as the speed of the motor increases.

But it is pretty safe to assume that as the speed goes up so does the load. With some fans doubling the speed increases the load by a factor of 4. In some you may cause cavitation and there will be little if any flow. So it isn't true that with twice the voltage the current goes down to half.

As for rewiring the motor, I wish removing a set of brushes would do it. But since most motors with brushes only have two, removing one set would cut the current and the speed significantly.

Seriously though, I called around a year or so ago looking for someone that would rewind a Bullnose blower motor to give more air movement. No one would touch it, with one guy saying it would cost "hundreds of dollars".

Thanks Gentlemen for your detailed answers.

And thanks Cory to have asked your questions!

This thread is very instructive!

[ArdWrknTrk]

Thank you gentlemen for all of the detailed answers. I knew that you guys would know what to do. Thanks for always being so helpful. Wiring this truck from scratch is going to be a bit of a task, but for the most part it will basically be wired up as an 80's pickup with a Duraspark ignition, a 3G alternator conversion and a Quick4 transmission controller, so if I run into any snags, I know where to go for help! Thanks again.

So placing the switch/resistor in the 6V circuit with a motor that only pulls 10A will probably give the same results as using it in a 12V circuit and a motor that pulls 20A.

Interesting point you make here Gary, and one I have to ask about out of curiosity. In my searches for information on this blower fan, I found a lengthy discussion on another forum a few weeks ago (Jalopy Journal, I think) where they were going over the options for running this 6v motor in a 12v system.

Apparently some guys just run the motors at 12v. Since these are mostly fair weathered vehicles these days, I doubt anybody runs the heaters very often. The argument was over the amperage. Quite a few people said that if you run the 6v motor with 12v that it will only draw half the amps the motor would draw with 6v. The other half of the people said no way, that it would not only draw the same 10amps the 6v would draw, but that it would draw much more than the 6v.

Anyway, I couldn't find much of an answer at the end of any of these debates, so I just said screw it, I'll run the motor at 6v and not worry about it.

If you're around old cars and trucks or even car shows, etc any length of time, one thing you'll notice is a fairly common occurrence: Fires. I don't want to contribute to that, so I'll try to do the "right thing" wherever possible (and I have a high tolerance for the wrong things by the way...lol).

PS: My brother in law suggested taking the motor to a motor shop and see if they would convert it to 12v for me. It said that it should be fairly simple. I think he said just remove one set of brushes and voila, it's a 6v motor.

Interesting.

I see this listing for a '52 F1 blower motor and it crosses with 66-70 Jeep CJ 5&6.

https://partshawk.com/four-seasons-35512-hvac-blower-motor-for-ford-f1.html

I'm surprised that there isn't a 12V replacement for them.

Here's a thread at FTE that claims a 12V direct replacement for $27. https://www.ford-trucks.com/forums/558426-12v-fan-motor-for-48-52-ford-heaters.html

Here's one on Amazon that looks identical:. https://www.amazon.com/Four-Seasons-Trumark-35576-without/dp/B000CNHAK8/ref=asc_df_B000CNHAK8/?tag=hyprod-20&linkCode=df0&hvadid=330386922177&hvpos=&hvnetw=g&hvrand=698069968451738485&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9003368&hvtargid=pla-679751117689&psc=1

All the specs seem to match the first partshawk listing except it says 12V

Number of Terminals: Connector Not Included

Connection Gender: None

Connector Qty: None

Connector Type: 2 Lead Wires

Description: Blower Motor /Single Shaft

Flanged?: No

Material: Metal

Motor Dia. "IN": 3.000

Motor Length "IN": 3.750

Mount Type: OE Mount

New or Remanufactured: New

Original Equipment Replacement?: Yes

Rotation: CW/CCW

Shaft Dia. "IN": 0.250

Shaft Length "IN": 1.500

Shaft Shape: D-Shaped

Stud Distance "IN": 2.3125

Style: Single Shaft

Type: Blower Motors

Vented?: Non Vented

Voltage: 12

Wheel?: w/o Wheel

 

[Rembrant]

Interesting.

I see this listing for a '52 F1 blower motor and it crosses with 66-70 Jeep CJ 5&6.

https://partshawk.com/four-seasons-35512-hvac-blower-motor-for-ford-f1.html

I'm surprised that there isn't a 12V replacement for them.

Here's a thread at FTE that claims a 12V direct replacement for $27. https://www.ford-trucks.com/forums/558426-12v-fan-motor-for-48-52-ford-heaters.html

Here's one on Amazon that looks identical:. https://www.amazon.com/Four-Seasons-Trumark-35576-without/dp/B000CNHAK8/ref=asc_df_B000CNHAK8/?tag=hyprod-20&linkCode=df0&hvadid=330386922177&hvpos=&hvnetw=g&hvrand=698069968451738485&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9003368&hvtargid=pla-679751117689&psc=1

All the specs seem to match the first partshawk listing except it says 12V

Number of Terminals: Connector Not Included

Connection Gender: None

Connector Qty: None

Connector Type: 2 Lead Wires

Description: Blower Motor /Single Shaft

Flanged?: No

Material: Metal

Motor Dia. "IN": 3.000

Motor Length "IN": 3.750

Mount Type: OE Mount

New or Remanufactured: New

Original Equipment Replacement?: Yes

Rotation: CW/CCW

Shaft Dia. "IN": 0.250

Shaft Length "IN": 1.500

Shaft Shape: D-Shaped

Stud Distance "IN": 2.3125

Style: Single Shaft

Type: Blower Motors

Vented?: Non Vented

Voltage: 12

Wheel?: w/o Wheel

Excellent finds Jim! I did come across that same thread on FTE, but that blower motor is for what they call the "Non Magic-Air" style heater, and mine IS the Magic Air style. I thought I had read elsewhere that the motors between the two different heaters were indeed different. Now you've got me thinking...I really need to pull mine and measure it up. I would love to find a 12v motor that fits.

Stay tuned for more...I'll pull the motor today or on the weekend and measure all of the dimensions.

Thanks Jim!