Need Help with simple 9V circuit design.

I'm not an electronics expert but have built 100s of devices by following schematics. I don't know electronic theory beyond the very basics.

I have the need to change an existing system. I have a motor driven by a 9V battery. It has a switch and a pot so I can change the speed. I want to remove the existing switch and pot and add a "Touch" switch component I found. I just need to be able to turn it "on" or "off" right now. The "Touch" switch is rated at 2.5-5.5V.

Are there a couple of simple components I can add so I can use this switch without burning it up? I can't find a higher voltage version.

 

Thank you all for these suggestions. Let me be more specific. I'm trying to modify this for a friend who has some kind of use for it. He asked if I could remove the pot and insert the touch switch. It's that cut and dry and that simple.

This is a circuit that was given to me. It's a motor that has a 9V battery, a switch and a pot. The Pot is 1K. At full power the motor runs at about 5RPM. I'm not concerned with whether this is a proper and good way to control motor speed. It's what I have.

I just want to add a small touch switch and can't find one of a higher voltage. I don't care about torque, it just needs to turn and have a small amount of torque. Imagine lightly pinching the shaft with your fingers. The motor has no specs on it so I don't know anything about it.

I was hoping that this touch switch could just open up a switch in the 9v circuit. The touch switch could have the 9v reduced to 5V and then it could then be used to merely open up a switch that's in the normal 9v path.

@PETERDECO, your suggestion may just work. That's the kind of advice I'm looking for. I'm not looking for a critique of the existing circuit, I'm just trying to modify what I have... be-it-as-it-may.

Thanks to all of you. I appreciate the fast responses. I know it can be frustrating when people like me come here and they have little electronics knowledge. But there are millions of us who tinker on things like this without much technical expertise. It's nice to have access to people like you for some hand holding. Much appreciated.

 

@PETERDECO , is this a correct modification of your schematic. I added two connections that might not have printed. You mentioned one but I was another that maybe should have been there.

 

This is all great info and has been educational. Little by little we learn, with lots of help. I've ordered parts. I'll post my success or failure later when I've assembled things. I appreciate the assistance very much.

 

Thanks for clarifying. So ok, I'll take the blue lead of the LP2950 that I showed going to another ground and connect it to the 9v(+) between the battery and the motor like the attached.

 

Thanks for all of this feedback and advice. I have parts in now and I'll start to test this. I'll report back.

 

Hi, I'm returning for a little advice. I've attached what I have wired (left hand schematic) and what was suggested above (right hand schematic). I have two needs:

1. When I power the system, the touch switch actuates the circuit but very quickly the 'LP2950' begins to smoke. I turned it off quickly and let it cool. I then momentarily applied the 9V and it started to work, so I didn't fry it.

2. Once I get it to run and not stress the LP2950, I'd like to add a pot in for speed control. The pot I show is from the original circuit I'm dismantling to add the touch switch in place of a standard mechanical sliding switch. How would I wire that pot into the circuit.

I appreciate the help with this. Obviously I'm not an electronics expert. I know just enough to wire from schematics but can't diagnose much and don't dare start reversing connections so I don't blow my components up. I'm a product designer but not an electrical engineer.