Need help - Ball valve and servo motor

[FiveO]

Hi

What I have:

Ball valve - **broken link removed**
Servo motor - **broken link removed**
Switch - simple push type

What i want:

I want that the ball valve is normally closed and if I press or hold down the switch/trigger then the ball valve opens and if i let the switch go, it closes.

How to make it happend? Can You help me?

 

[MaxHeadRoom78]

There are quite a few RC controller servo circuits built around the 555 for e.g.
Google should get quite a few
Max.

 

[Les Jones]

The specification of the servo is meaningless. kg is NOT a unit of torque. Torque is measured in units of force times distance. (Distance being the distance from the axis of rotation that the force is applied.) I have used a similar model servo to drive a butterfly valve to control airflow. This probably does not need as much torque as the ball valve in your link.
This is a link to the way I have used the servo. https://lesjhobbies.weebly.com/blower-system-for-my-waste-oil-burner.html

Les.

 

[alec_t]

The valve needs to turn through 90°, whereas a standard servo rotates through ~ 180°. So a simple linkage gives you only a 2:1 mechanical advantage at best. That means the servo torque needs to be at least half the torque required to turn the valve. Allowing for inefficiencies I would suggest the servo torque should be a good bit more than the valve torque. You can measure the valve torque by using a spring balance pulling on the handle end.

 

[MaxHeadRoom78]

You can measure the valve torque by using a spring balance pulling on the handle end.

Plus the length of the handle.
Max.

 

[dr pepper]

This gets you part the way there,

**broken link removed**

Only the servo turns as you turn the pot on the front.
You could switch power off and on to the tester using the switch while keeping power on at the servo, but that will only use 1/2 the rotation of the servo, you might be able to do it using an intermediate linkage.

Oh yeah welcome to the forum.

 

[jpanhalt]

In this application, I do not think power needs to be kept on the servo at all. Since two wires need to go from the controller to the servo anyway (i.e., signal and ground), I would just use a standard three-wire set up and turn power completely off after resetting the valve.

John