Help with adding a component into a simple circuit

[Jstagzsr]

I bought a heat gun. it works great. I'm actually surprised how well it works with being so inexpensive.. Let's see how long it lasts.. thats a whole other story.. But the issue is, you plug it in and turn it on.. My only 2 options are off and full blast.. I took apart the case to see what the inside looked like Its a very simple circuit.. 110v ac in, theres a switch, a brushed motor with fan blades attached to it using the body of the heatgun as the path for moving air, and theres what appears to be a cardboard tube with a piece inside that has coiled wire wrapped around it..

I would like to add in whatever i can fit in there that would give me the functionality of turning the fan up and down, and Turning the heat up, down and off. For those who know what theyre doing, what would i need to do here? I would prefer there to be two twisting knobs in the end. One for airflow, one for heat so i can make it gradual however hot or powerful i want.

Also, If this could be as cheap as possible that would be awesome.. If this is gonna cost me 100 bucks in parts then ill just go buy another, better heat gun.

[TetraSky]

So... you would like to add something like a potentiometer in there to control the voltage that's allowed to go to the components?

 

Technically, it could be done relatively inexpensively... But unless you know what you're doing, I wouldn't recommend it.

[Jstagzsr]

1 minute ago, TetraSky said:

So... you would like to add something like a potentiometer in there to control the voltage that's allowed to go to the components?

Exactly. But is it as simple as that? Add in a potentiometer to the wires going to the motor, and add another potentiometer on the wires going to the coils? This will be the first time doing anything with 110v. It scares me a little. lol

[TetraSky]

10 minutes ago, Jstagzsr said:

Exactly. But is it as simple as that? Add in a potentiometer to the wires going to the motor, and add another potentiometer on the wires going to the coils?

I mean, it's either that, or go the super jank way and put a light dimmer on the circuit instead. lol

Would probably be easier.

 

Actually, instead of a potentiometer, might be better to use a variable resistor.

They can technically do the same job, but if there's just two cables, the variable resistor would be preferable.

For the potentiometer to act the way you want, you would have to tie one of its "leg" to the other, which is one extra step where things could go wrong. As such, simply getting a variable resistor in the first place, might be better (a light dimmer is a sort of variable resistor).

[AbydosOne]

Unless you know exactly what you're doing, don't play with the 110VAC side of electronics. Just buy the heatgun that has the features you want/need. The effort really isn't worth the risk of electrocuting yourself or combusting your domicile.

 

1 minute ago, TetraSky said:

So... you would like to add something like a potentiometer in there to control the voltage that's allowed to go to the components?

At the level of power being drawn, pretty much any pot would vaporize itself almost instantly. Any energy not being used by the heatgun needs to be dissipated (as, ironically, heat) by the voltage divider (which is dangerous and inefficient). You'd need some sort of AC chopper (like a household dimmer switch) for the heat side, but AC motors may be harder to regulate (if they don't start properly, they'll stall and windings will melt).

[Jstagzsr]

1 minute ago, AbydosOne said:

Unless you know exactly what you're doing, don't play with the 110VAC side of electronics. Just buy the heatgun that has the features you want/need. The effort really isn't worth the risk of electrocuting yourself or combusting your domicile.

 

At the level of power being drawn, pretty much any pot would vaporize itself almost instantly. Any energy not being used by the heatgun needs to be dissipated (as, ironically, heat) by the voltage divider (which is dangerous and inefficient). You'd need some sort of AC chopper (like a household dimmer switch) for the heat side, but AC motors may be harder to regulate (if they don't start properly, they'll stall and windings will melt).

Yeah thats exactly what im worried about.. Thats a lot of V's and A's in that plug.. Not quite the arduino's and SBC's i'm used to dealing with..

[Jstagzsr]

8 minutes ago, TetraSky said:

I mean, it's either that, or go the super jank way and put a light dimmer on the circuit instead. lol

Would probably be easier.

 

Actually, instead of a potentiometer, might be better to use a variable resistor.

They can technically do the same job, but if there's just two cables, the variable resistor would be preferable.

For the potentiometer to act the way you want, you would have to tie one of its "leg" to the other, which is one extra step where things could go wrong. As such, simply getting a variable resistor in the first place, might be better (a light dimmer is a sort of variable resistor).

oh actually, thats a good idea.. An in wall type dimmer would be able to handle the power and do exactly what i want.. GREAT idea!! definitely janky but ill take a janky working end result over an electrocution and magic smoke electronics. lol

[TetraSky]

Just now, Jstagzsr said:

oh actually, thats a good idea.. An in wall type dimmer would be able to handle the power and do exactly what i want.. GREAT idea!! definitely janky but ill take a janky working end result over an electrocution and magic smoke electronics. lol

Well, whether or not it can handle it, that's something I don't know.

A heatgun typically take up 1500W. At 110V, that's nearly 14A. Would the dimmer able to handle it? ... I don't know.

But well, it can be a fun experiment. As an electrical student I would certainly love do to something like that for funsies instead of playing around with motors. What could possibly go wrong, right?

[Jstagzsr]

5 hours ago, TetraSky said:

Well, whether or not it can handle it, that's something I don't know.

A heatgun typically take up 1500W. At 110V, that's nearly 14A. Would the dimmer able to handle it? ... I don't know.

But well, it can be a fun experiment. As an electrical student I would certainly love do to something like that for funsies instead of playing around with motors. What could possibly go wrong, right?

I was picturing the ones that are meant for multiple bulbs and a ceiling fan. I think thatll be able to take the amp draw.. We'll find out anyway. haha. I really wish i could use a few potentiometers tho. That would be perfect.

[akio123008]

11 hours ago, Jstagzsr said:

I really wish i could use a few potentiometers tho. That would be perfect.

Potentiometers aren't at all designed for power control. Like it's not even close.

 

A bulky variable resistor (also known as rheostat) could do the job, but it's a terrible solution as it produces loads of heat and wastes power.

 

A chopper based circuit of somekind (like a light dimmer) would be best, but chopper based power controllers for very high power loads (such as heatguns) can be expensive. 

 

What I would certainly suggest is that whatever you do, instead of trying to build the power controller into the heatgun, build it as a standalone device with a power outlet on it, that you can then plug the heatgun into. That way you avoid modding the device itself, and you have the added bonus of being able to control the power level of other machines as well (this can be great for all sorts of tools). 

 

[artuc]

The problem is this is all better done at the design stage and built into the product.

 

Heat control you could have multiple elements, say 2 of the same size and a 3 position switch that switches one or both in for high or low.

 

The motor can be a type with different windings/poles you can switch between for different speeds.

 

Much harder to retrofit these sort of things after.

[Jstagzsr]

On 11/15/2020 at 12:03 PM, akio123008 said:

Potentiometers aren't at all designed for power control. Like it's not even close.

 

A bulky variable resistor (also known as rheostat) could do the job, but it's a terrible solution as it produces loads of heat and wastes power.

 

A chopper based circuit of somekind (like a light dimmer) would be best, but chopper based power controllers for very high power loads (such as heatguns) can be expensive. 

 

What I would certainly suggest is that whatever you do, instead of trying to build the power controller into the heatgun, build it as a standalone device with a power outlet on it, that you can then plug the heatgun into. That way you avoid modding the device itself, and you have the added bonus of being able to control the power level of other machines as well (this can be great for all sorts of tools). 

 

Thats actually a great idea! then i could use it for many things, not just this.. what an awesome idea.. TY!!