Battery power

[Erin_M]

Hello! I am new to micro-controllers and programming, but I have a very specific project in mind and have a couple of questions. Keep in mind that I am a complete noob with this stuff.

Okay, so I'm trying to make a small fog machine that will be battery powered and be programmed with a timer to produce fog every few seconds. I'm trying to make this fogger as practical and user friendly as possible.

Q1: The fogger functions on a set of rechargeable batteries (35A 18650 2500mAh 3.7v). Can I run both the Prop-1 and the fogger off of these batteries?

Q2: I want the fogger to be completely battery powered regardless of whether or not I can use the same source for Prop-1 and the fog elements. So, is there some sort of adapter or connector to hook up the Prop-1 to a battery pack?

Q3: I would really like to have a knob or knobs on the outside of the fogger casing that would allow me to adjust the timing of the fogger as needed for any given situation. I saw the Prop-Pot on the EFX-TEK site that seems like the right thing, but wouldn't be able to stick out past the casing. What would work for that or is there a way to get the Prop-Pot to work for what I need?

Thank you for any help!  ;D

[bsnut]

First welcome to the forums.

Now its time to answer your questions that you have for this interesting project that you have.

Q1: The fogger functions on a set of rechargeable batteries (35A 18650 2500mAh 3.7v). Can I run both the Prop-1 and the fogger off of these batteries?

Yes, the Prop-1 can be run off a battery. But, I would suggest that you use a 12 volt battery even tough that the Prop-1 can run off a 9 volt battery.

Q2: I want the fogger to be completely battery powered regardless of whether or not I can use the same source for Prop-1 and the fog elements. So, is there some sort of adapter or connector to hook up the Prop-1 to a battery pack?

Very doable. That's no problem. Just size the battery to the load.

Q3: I would really like to have a knob or knobs on the outside of the fogger casing that would allow me to adjust the timing of the fogger as needed for any given situation. I saw the Prop-Pot on the EFX-TEK site that seems like the right thing, but wouldn't be able to stick out past the casing. What would work for that or is there a way to get the Prop-Pot to work for what I need?

You will be able to do what you want to do without using the Prop-Pot. Just look at the Prop-Pot drawing in the PDF for the Prop-Pot to show you how the pots are interfaced to the Porp-1 pins. Also in the forums we many examples that show you the same thing.

When it comes to your program, give us all the details. The more info you provide, the easier for us to help you get what you are looking for. 

[JonnyMac]

1. You say a "set" of batteries. What does that mean, exactly? As long as your battery stack is at least 9v, you can control the Prop-1 with it.

2. Yes. You can connect your battery to the V+ and GND terminals on the Prop-1. Move the power switch to P2

3. Use the Prop-Pot for circuit testing and program design, then use a standard pot with a shaft in your device; this will let you mount it to a case. You'll need to solder a 0.1uF cap in line.

[Erin_M]

Sorry, by "set" I meant "pair." There are two batteries with the previously stated specs. They are 3.7V each so that isn't enough is it? Drat, I was really trying to keep the battery system as simple and easy to handle as possible.

The other thing I'm worried about is that the fogger uses the battery power in a heating element to produce the fog. Since the heating element is basically a short in the current, I want to make sure that type of energy flow won't damage the controller, and that if I have to use more batteries to power the controller, that I can limit the amount of energy going to the heating element so that it doesn't burn out right away.

I'm not sure what a 0.1uF cap is...

I'll go ahead and get everything set up and laid out for the most part and post a picture of it here so you can see what I'm working with.

[JonnyMac]

It will probably work, but it's a bit on the low side. The onboard regulator needs a little overhead to operate. 7.2 volts in might be okay, but I'd like to see it a little higher. You could stack 3 batteries to get 11.1 volts. Use this for the controller input, then tap between the 2nd and 3rd to get 7.2 volts for the fogger.

[JackMan]

The other thing I'm worried about is that the fogger uses the battery power in a heating element to produce the fog. Since the heating element is basically a short in the current, I want to make sure that type of energy flow won't damage the controller, and that if I have to use more batteries to power the controller, that I can limit the amount of energy going to the heating element so that it doesn't burn out right away.

I'm not sure what a 0.1uF cap is...

You won't be able to directly switch that much current through the Prop-1, you'll need to connect a suitable relay to the Prop-1 output and the relay will switch the power on and off to the heating element. I've attached a picture of a typical .1uf capacitor. (there's actually 4 of them in the picture)

[bsnut]

Use the Prop-Pot for circuit testing and program design, then use a standard pot with a shaft in your device; this will let you mount it to a case. You'll need to solder a 0.1uF cap in line.

This is what Jon was talking about. So, I attached the PDF for the Prop-Pot to show you electrical drawing. This drawing shows you how the cap comes in to play with the pot
http://www.efx-tek.com/downloads/ez-3_docs.pdf