Pressure Plate Project

Thread Starter

TXJackII

Joined Apr 1, 2019
8
New to electronics but moderately capable. I am looking for assistance creating a circuit diagram for a pressure plate but with a twist: I need to power a small vibrating disc motor when the circuit is open (i.e., when the force upon the pressure plate is lifted). I presume that a capacitor of some sort will be required and that. Capacitance need only be strong enough to power vibrating motor disc through discharge cycle. When pressure plate circuit is closed, the capacitor needs to charge but without current flowing to disc motor. Possible?
 

Bernard

Joined Aug 7, 2008
5,254
What is V to the pressure plate, & AC or DC ?
Can de done. Might shunt vib. motor with N ch FET or something, will need a big cap. & more inf. on vib. motor.
A small DC motor ran for 1 sec. from a 5,000 mF cap. charged to 12 V.
 
Last edited:

Thread Starter

TXJackII

Joined Apr 1, 2019
8
What is V to the pressure plate, & AC or DC ?
Can de done. Might shunt vib. motor with N ch FET or something, will need a big cap. & more inf. on vib. motor.
A small DC motor ran for 1 sec. from a 5,000 mF cap. charged to 12 V.
 

Thread Starter

TXJackII

Joined Apr 1, 2019
8
I would imagine that V to pressure plate is minimal, 2-5v dc, but open to suggestion. This is a haptic set-up so minimal is king. Mini disc motor will function fine on 2-5V says Adafruit. Cap need only suffice to fire mini disc motor for 1-2 sec. Did I answer your questions? Thanks.
 

Thread Starter

TXJackII

Joined Apr 1, 2019
8
What is V to the pressure plate, & AC or DC ?
Can de done. Might shunt vib. motor with N ch FET or something, will need a big cap. & more inf. on vib. motor.
A small DC motor ran for 1 sec. from a 5,000 mF cap. charged to 12 V.
I would imagine that V to pressure plate is minimal, 2-5v dc, but open to suggestion. This is a haptic set-up so minimal is king. Mini disc motor will function fine on 2-5V says Adafruit. Cap need only suffice to fire mini disc motor for 1-2 sec. Did I answer your questions? Thanks.
 

Bernard

Joined Aug 7, 2008
5,254
Maybe use a driver for vib. to reduce size of cap. Could use other forms of timer, even a 555.
 

surri

Joined Mar 11, 2019
11
It would be good if you could specify more on the motor and the use case (what will vibrate, why, power supply, env. conditions etc etc.), there are perhaps other solutions like some have mentioned.
 

Bernard

Joined Aug 7, 2008
5,254
My solar motor, under load, runs for about 1 s from 5V charge af 5000 uF cap. Adafruit mini vib. disc motor 2 -5V @ 100ma may be similar.
 

Thread Starter

TXJackII

Joined Apr 1, 2019
8
My solar motor, under load, runs for about 1 s from 5V charge af 5000 uF cap. Adafruit mini vib. disc motor 2 -5V @ 100ma may be similar.

B, maybe I need to wave off the pressure plate concept and instead find a switch that works exactly the opposite: when pressure is relieved, the circuit is closed.
 

Bernard

Joined Aug 7, 2008
5,254
We work pretty cheap; what do you want to know. Where are you ? What resources do you have , parts supplier ?
 

Thread Starter

TXJackII

Joined Apr 1, 2019
8
We work pretty cheap; what do you want to know. Where are you ? What resources do you have , parts supplier ?
Understood. Please tell me how this works. I don't wish to break any site rules but I also don't wish to capitalize on your work without a fair exchange, as it were.

I'm in San Antonio.

Jack
 

AnalogKid

Joined Aug 1, 2013
8,100
I might have missed this part:

Motor voltage?

Motor current?

Motor run time?

Voltage available to run the system / charge the capacitor / etc?

Pressure plate size?

Plate travel when pressed?

Plate design - hinged along one side / four corner springs / etc?

ak
 

Bernard

Joined Aug 7, 2008
5,254
When SW is closed C1, 1 micro F , is charged thru D1 & current is supplied to base of Q2, which grounds base of Q1, a high impedance input darlington transistor. Motor does not run. SW opens, Q2 turns off allowing charge on C1 to turn on Q1., motor runs until C1 discharges thru R1 & base of Q1 but mostly thru R2. D1 prevents C1 from discharging thru R3-R4. A 1 meg. pot could replace R2 for timing test
 

Thread Starter

TXJackII

Joined Apr 1, 2019
8
When SW is closed C1, 1 micro F , is charged thru D1 & current is supplied to base of Q2, which grounds base of Q1, a high impedance input darlington transistor. Motor does not run. SW opens, Q2 turns off allowing charge on C1 to turn on Q1., motor runs until C1 discharges thru R1 & base of Q1 but mostly thru R2. D1 prevents C1 from discharging thru R3-R4. A 1 meg. pot could replace R2 for timing test
B, I was not very clear. My point was that I feel compelled to compensate you for the help you have provided and for the time you spent doing it. Additionally, I have another, far more promising EE project. I wonder if we might discuss it in a more private manner.
When SW is closed C1, 1 micro F , is charged thru D1 & current is supplied to base of Q2, which grounds base of Q1, a high impedance input darlington transistor. Motor does not run. SW opens, Q2 turns off allowing charge on C1 to turn on Q1., motor runs until C1 discharges thru R1 & base of Q1 but mostly thru R2. D1 prevents C1 from discharging thru R3-R4. A 1 meg. pot could replace R2 for timing test
 

Bernard

Joined Aug 7, 2008
5,254
You might have better luck in posting on AAC as most of the members are smarter than me, but if you wish I could review your project..
I'm not conversant with micro processors & usually stay under about 10 chips.
 
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