Exhaust valve actuator

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BR1988

Joined Apr 14, 2021
51
You will have to find an appropriate module, although I don't know from the documentation of your valve if the 5V signal would work. It's easy to get 5V from 12, but all these details, which honestly are simple, compound to make a project that needs either knowledge or handholding.

Some people here will take something like this on, and help with all the details, but it's going to be a step-by-step process.

I have too many things going on to be helpful with yet another project so I am trying to avoid leading you in a direction you can't go by yourself.
Its okay, I understand you’re reaction this isn’t a easy project with the lack of knowledge I have. So thanks again for the effort!
 

BobaMosfet

Joined Jul 1, 2009
2,110
Yes, I did some reading about pwm. And after what you wrote I do understand that this isn’t you’re normal on/off switch.

but, how is it possible to create the signal the valve needs to do it without the Bluetooth module?
because a company did this and the box is very little so there isn’t much in there. Also, I saw some one from Belgium also created something. But you guessed it they won’t give me any information.
Are there relay switches boards that uses pwm cycle and can be altered? Ore Am i not thinking straight. ?
It's called using a 555 IC to generate a 100Hz signal, and an AND gate to turn it on or off, as the core of the system. Other components and so forth are necessary to actually do it. Welcome to Electronics-

Title: Understanding Basic Electronics, 1st Ed.
Publisher: The American Radio Relay League
ISBN: 0-87259-398-3
 

Thread Starter

BR1988

Joined Apr 14, 2021
51
If what he is trying to control is what I think it is, an exhaust cutout, I would think he wants a RC servo motor controller not a PWM module. https://learn.sparkfun.com/tutorials/hobby-servo-tutorial/all
It’s a cutout but not the tipical AliExpress, it uses a 3 pin connector. Has a continuous -12v and +12v and a pwm signal wire.
from factory controlled by a Bluetooth module. Also see the data sheet attached. It is not a stepping motor.
it has to positions open and close.
It act fully and not partly after pressing the Bluetooth remote or in my case the switch to on, it wel open the flap at once. When i switch to off it closes the flap.
I’ll try and post the in side off the Bluetooth module iff I can. Maybe that gives some more information.
 

shortbus

Joined Sep 30, 2009
10,045
factory controlled by a Bluetooth module. Also see the data sheet attached. It is not a stepping motor.
it has to positions open and close.
Other than the Bluetooth you just described what a RC servo controller does. Bluetooth just takes the place of a radio for the remote control.
 

Thread Starter

BR1988

Joined Apr 14, 2021
51
Other than the Bluetooth you just described what a RC servo controller does. Bluetooth just takes the place of a radio for the remote control.
Iff that’s the case, then applying a servo controller would be a solution?
I’ll read the link you posted and see iff I understand and why it could be a solution. But using a multimeter and read 2times +12v and a -12v then applying that samen method with out the bt module it didn’t work.
So applying a direct current to the pwm position 1 wire did not do anything.
what dit was applying +12v and -12v to position 2 and 3. The valve opens but stays there no mater what I did.
 

Ya’akov

Joined Jan 27, 2019
9,044
Other than the Bluetooth you just described what a RC servo controller does. Bluetooth just takes the place of a radio for the remote control.
es, but according to the specifications he posted there are only two valid positions—open and closed—and only two valid signals: 10% PWM and 90% PWM. It fails open.
 

LesJones

Joined Jan 8, 2017
4,174
From another thread on exhaust valves it seem that some of them can be stopped at any point in their travel. If only fully open and fully closed positions are required then just having an NE555 running at 10% duty cycle with an inverter (A single transistor) on the output would make it a bit simpler. Just select the non inverted signal for 10% and select the inverted signal for 90%
Model control servos control signal is similar but it is more pulse length modulation than PWM in the normal sense.
The model system runs at a nominal frequency of 50 hz (The frequency is not critical.) The pulse duration is 1 mS for one end of the travel and 2 mS for the other end of travel. So IF running at the nominal frequency of 50 hz (Period of 20 mS) the duty cycle is 5% to 10%.
BR1988, are you looking for a ready built unit or a design that you can build yourself ? Are you experienced at building electronics projects and the required test equipment ?

Les.
 

Thread Starter

BR1988

Joined Apr 14, 2021
51
From another thread on exhaust valves it seem that some of them can be stopped at any point in their travel. If only fully open and fully closed positions are required then just having an NE555 running at 10% duty cycle with an inverter (A single transistor) on the output would make it a bit simpler. Just select the non inverted signal for 10% and select the inverted signal for 90%
Model control servos control signal is similar but it is more pulse length modulation than PWM in the normal sense.
The model system runs at a nominal frequency of 50 hz (The frequency is not critical.) The pulse duration is 1 mS for one end of the travel and 2 mS for the other end of travel. So IF running at the nominal frequency of 50 hz (Period of 20 mS) the duty cycle is 5% to 10%.
BR1988, are you looking for a ready built unit or a design that you can build yourself ? Are you experienced at building electronics projects and the required test equipment ?

Les.
Hi Les,
Thank you for your explanation. To answer your question, to be honest I have a multimeter and a voltage converter, and that's it. I have soldered some circuit boards once, but that was a very long time ago. I learn quickly and understand things quite quickly. Sure, a ready-made system would be a nice thing, where minor adjustments might have to be made. But with the right components I can also build some, but I may not have all the electronic equipment that is needed. Yaakov showed me a pwm module maybe thats a start?

The intention is therefore to be able to switch the motor with a physical switch or a wireless switch.
 

Thread Starter

BR1988

Joined Apr 14, 2021
51
Hi Les,
Thank you for your explanation. To answer your question, to be honest I have a multimeter and a voltage converter, and that's it. I have soldered some circuit boards once, but that was a very long time ago. I learn quickly and understand things quite quickly. Sure, a ready-made system would be a nice thing, where minor adjustments might have to be made. But with the right components I can also build some, but I may not have all the electronic equipment that is needed. Yaakov showed me a pwm module maybe thats a start?

The intention is therefore to be able to switch the motor with a physical switch or a wireless switch.
I do have a test board, where i can build my own circuit. but i dont have a scope. My dad been in the electronic's for a long time, so he knows some stuff but not all. I also have some electronic items like transistors, and resistors.

What do i need to start this, will a module that yaakov sugested be good to buy? Hope to hear from you.
 

shortbus

Joined Sep 30, 2009
10,045
Iff that’s the case, then applying a servo controller would be a solution?
I’ll read the link you posted and see iff I understand and why it could be a solution. But using a multimeter and read 2times +12v and a -12v then applying that samen method with out the bt module it didn’t work.
So applying a direct current to the pwm position 1 wire did not do anything.
what dit was applying +12v and -12v to position 2 and 3. The valve opens but stays there no mater what I did.
You seem to be thinking there is no electronics in the system that moves the valve flapper. Applying higher(12V) and negative (-12V) to the part that is expecting a much lower pulsed signal, you may have destroyed your cutout. Another question is, where in a car are you getting -12V???

The 12V is to power the servo motor, that actually moves the flapper, butterfly valve. The signals you are calling PWM are to the controls that signal the motor to move. I for one don't believe they are PWM, but are just the frequency needed to make the servo work.
 

shortbus

Joined Sep 30, 2009
10,045
es, but according to the specifications he posted there are only two valid positions—open and closed—and only two valid signals: 10% PWM and 90% PWM. It fails open.
The way I read it is that he applied full 12V to the circuit it moved the valve flap and died. He is/was randomly applying 12V to things, some of those things weren't expecting to see a steady 12V so it killed the controller.
 

Ya’akov

Joined Jan 27, 2019
9,044
The way I read it is that he applied full 12V to the circuit it moved the valve flap and died. He is/was randomly applying 12V to things, some of those things weren't expecting to see a steady 12V so it killed the controller.
I have no idea if he damaged the device. According to the documentation he provided, it is controlled with a PWM signal and has two states, as I said.

I think this is to provide compatibility with other similar hardware. The PWM signal seems to be at 12V and the docs say an invalid signal will yield open.
 

Thread Starter

BR1988

Joined Apr 14, 2021
51
You seem to be thinking there is no electronics in the system that moves the valve flapper. Applying higher(12V) and negative (-12V) to the part that is expecting a much lower pulsed signal, you may have destroyed your cutout. Another question is, where in a car are you getting -12V???

The 12V is to power the servo motor, that actually moves the flapper, butterfly valve. The signals you are calling PWM are to the controls that signal the motor to move. I for one don't believe they are PWM, but are just the frequency needed to make the servo work.
Hi there,
no i do think there are electronics inside, because it’s a 3wired system and not a 2 wired where the motor is just switched by positive and negative.
But, the only thing I did whas applying the voltage to the pins where I checked the voltage with a multimeter.
And also looking at the system that’s been build bij the company for this valve motor.
I applied -12v (ground) to position 2. And +12v (positive) to position 3
And then I applied +12v (positive) to position 1.
Because that’s also the voltage i saw with my multimeter.

I did not fry the system/electronics or the motor and it still works.

the -12v (ground) comes directly from the chassis of the car.
 

Thread Starter

BR1988

Joined Apr 14, 2021
51
The way I read it is that he applied full 12V to the circuit it moved the valve flap and died. He is/was randomly applying 12V to things, some of those things weren't expecting to see a steady 12V so it killed the controller.
As I said I applied it the way I saw it after I checked the voltage outcome off the wires using my multimeter.
Not randomly like you said.
But I do understand the way you think.
 

Thread Starter

BR1988

Joined Apr 14, 2021
51
I have no idea if he damaged the device. According to the documentation he provided, it is controlled with a PWM signal and has two states, as I said.

I think this is to provide compatibility with other similar hardware. The PWM signal seems to be at 12V and the docs say an invalid signal will yield open.
No I have not damaged the device.

but when the engine is not running but the valve is active the green wire (position 1) shows +12v positive.
The red wire (position 3) the same
And the black wire -12v (ground) (position 2)

when I started the engine and the valve is active
Green and red wires are +14v
Black wire is stil -12v (ground)
 
Last edited:

LesJones

Joined Jan 8, 2017
4,174
I don't think we have any evidence either way as to whether the application of +12 volts to the signal input has caused any damage. The fact that the signal input floats to +12 volts may suggest that it is designed to be driven from an open collector NPN driver. I am not sure from your from your first post if you actually have the Bluetooth driver or you a saying that the actuator is designed to work with it. If you have the Bluetooth driver and know someone with an oscilloscope you could look at the signal.
I have had a look on ebay to see if I could find any ready made modules that would be a basis for a controller. The ones for motor speed control had an operating frequency of tens of Khz which is too high. The lack of test equipment would make it difficult for a beginner to modify them for 100 hz. I found this one but I don't think it will cover both ends of the duty cycle range as I can't see any diodes to route the charge and discharge current trough different resistors.

Les.
 

Ya’akov

Joined Jan 27, 2019
9,044
I don't think we have any evidence either way as to whether the application of +12 volts to the signal input has caused any damage. The fact that the signal input floats to +12 volts may suggest that it is designed to be driven from an open collector NPN driver. I am not sure from your from your first post if you actually have the Bluetooth driver or you a saying that the actuator is designed to work with it. If you have the Bluetooth driver and know someone with an oscilloscope you could look at the signal.
I have had a look on ebay to see if I could find any ready made modules that would be a basis for a controller. The ones for motor speed control had an operating frequency of tens of Khz which is too high. The lack of test equipment would make it difficult for a beginner to modify them for 100 hz. I found this one but I don't think it will cover both ends of the duty cycle range as I can't see any diodes to route the charge and discharge current trough different resistors.

Les.
I am not sure that it is 100Hz. It is almost certainly not the 100MHz own the datasheet, but is could be 100KHz.
 

djsfantasi

Joined Apr 11, 2010
9,155
Post #6 seems specially helpful for adaptation.
I don’t like post #6 because it shows driving a relay, not a servo motor.

@BR1988 It looks like the motor and electronics are a servo, but not necessarily an RC servo. Modern servos are driven by a different type of PWM signal based on the duty cycle and at some frequency and not the frequency (50Hz) AND duty cycle (as in an RC servo). Read this Wikipedia article.

The major point is that the valve is controlled by a specific pulse signal for open and closed.

A servo control module may not work, especially if it’s designed for RC servos. If it were to work, it’d have to output two different pulses, 10% duty cycle and 90% duty cycle. And it could be controlled in several different ways and you’d have to pick one that works for your design.

Note that the Bluetooth module is first a remote control module. It likely includes a PWM circuit for the two required duty cycles.

In your project, you’d need to duplicate the PWM circuit and control it via a switch. It’s possible to modify a push button two-position RC Servo control circuit based on a 555.
 
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