Hello, I am looking for circuit design help. I do NOT know any programming SO off the shelf parts would be Greatly appreciated.

What I have: Lipo main battery- 3.7v 500mAh 1.85Wh
Mini D.C Motor - 3.7v DC 40KRPM

I need a circuit that:

1. Will physically fit inside a 15mm cylinder, No larger will fit. Length of circuit also a internal size factor. Some flex in length available.
2. Will work off of the Lipo 3.7v Main battery
3. Will power the DC Motor directly at Instant full power
4. Will ONLY work after a external magnet is removed from the circuit.
5. Will Only run from a variable 10 - 25 Sec. set by a variable pot to the desired powered on time.
6. Can be reset with the use of the same magnet placement to the circuit Surface.

Can you please let me know IF you can help and a Clear Circuit will be Greatly appreciated.

Thank You for your Time / Help.

 

Try changing the tone of your post.
Most people are on this forum for fun, and to help others learn.

Your post reads like you expect someone to just do your work for free.

 

Try changing the tone of your post.
Most people are on this forum for fun, and to help others learn.

Your post reads like you expect someone to just do your work for free.

First, Thanks for your reply.

I did NOT know that this site was a site for people to make an income from others.

I was hoping for design help and I do not know circuit design. I can assemble circuits with a schematic drawing.

I am a model builder and this is for my own use, not to make money from.

If anyone here would be willing to help me with this, I would appreciate the help.

Thanks again for your Time and Help.

 

Thanks again for your Time and Help.

Timing is closer to 7 sec minimum to 31 seconds max.
Doable on a single or dual sided pcb using surface mount components.

 

Timing is closer to 7 sec minimum to 31 seconds max.
Doable on a single or dual sided pcb using surface mount components.
View attachment 361440

Thank You very much for your help. Can I ask you a few questions for the above circuit?

 

Thank You very much for your help. Can I ask you a few questions for the above circuit?

Sure.

 

View attachment 361440

I might be reading this wrong, of course, but don't the design specs call for the motor to operate when the magnet is REMOVED? If the AH182 is connecting to -ve when the magnet is present, it will need inverting.

 

The output from the AH182 is Low when the magnet is present.

 

The output from the AH182 is Low when the magnet is present.

... so when the magnet is present, the motor will run, yes? The opposite of what was asked for.

 

No, the motor runs when the magnet is removed.
Reset pin4 is held low when the magnet is present
Modified circuit, R2 not needed.

 

Instead of designing a circuit get the motor you want to use and start from there. Just my 2¢ worth. The circuit is going to be designed around it somewhat.
Wendy's Index
The 555 Projects

 

Instead of designing a circuit get the motor you want to use and start from there. Just my 2¢ worth.

The TS mentioned " Mini D.C Motor - 3.7v DC 40KRPM"

 

Need the complete specs on the motor.

 

Doubt it draws more then a few hundred milliamps.
The AO3400 can handle over 4 amps.

 

Hello again
Thank You to ALL of you coming forward with advice/help.

Sorry I forgot one more in my initial list at the start.

The motor is ONLY needed to run in One direction at full speed till the timer runs out and a magnet is placed in contact with the circuit and the circuit resets itself. Then when the magnet is removed again, the motor runs for the set time.

 

Currently the circuit is designed to reset anytime the magnet is near the AH182 sensor even if the motor is running.
Is that acceptable?

 

Currently the circuit is designed to reset anytime the magnet is near the AH182 sensor even if the motor is running.
Is that acceptable?

YES Very much appreciated.
You think IF all surface mounted parts are used then this circuit should fit inside a 15mm dia.. cylinder?

What is the final schematic drawing above for reference?

 

How tall is the cylinder?
What all needs to be inside the cylinder?

 

This requested design seems like it is for a high speed grinder type of tool used by a model builder. A tool that starts every time it is picked up seems to me to be rather unsafe.

 

This requested design seems like it is for a high speed grinder type of tool used by a model builder. A tool that starts every time it is picked up seems to me to be rather unsafe.

Hi, No this is for a model torpedo, electric powered. safety off switch is the magnet. When the torpedo is pushed slightly out of the magnet fixed position, then it turns on and runs for a set Sec. amount of time.

To answer the other posters questions ALL of the parts listed at the start will be inside the torpedo body.

Again Thank You ALL for your Time and help.