Pulsating Valve-circuit. Controllable impulses

  • Thread starter Bassalisk
  • Start date
In summary, a valve is an inductor that works at 24V DC, rated 5W. It gets an impulse, attracts the ferromagnetic inside, and goes into off mode. My questions are: 1.Can I use something like 555 timer to get these signals? 2.I have to be able to control the number of pulsations per second. Ideally through some pot. Is this possible with 555 timer?(I am really new to 555 timers, but understanding them shouldn't be a problem). 3.If 555 timer cannot handle these kinds of voltages, should I use some relay? Are we raising the question of response time? I am going shopping for 555 timer tomorrow, so can you be more specific about this
  • #1
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So I have this valve(see attachments).

That valve is basically an inductor. It works at 24V DC, rated 5W. At third picture you will see a piston. This is all about 8 cm long (3rd picture including the piston). Just to give you the feeling of size.

How this piston has to work:

It gets an impulse, it attracts the ferromagnetic inside. Let's call that "on" state. After that the circuit goes into off mode, and that little spring that you see at 3rd picture pulls the piston back.

My questions:

1.Having on mind that 24V DC isn't much, could I use something like 555 timer to get these signals?

2. I have to be able to control the number of pulsations per second. Ideally through some pot. Is this possible with 555 timer?(I am really new to 555 timers, but understanding them shouldn't be a problem). We are talking about range of 2-15 impulses per second.

3. If 555 timer cannot handle these kinds of voltages, should I use some relay? Are we raising the question of response time?

I am also aware that I should install the flyback diode, to get better response.

Any suggestions are more than welcome.

Thank you
 

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  • #2
A 555 would not be able to directly drive an actuator like that. They have an upper voltage limit of 18 volts and a current rating of 200 mA. In practice, you would not use more than 75% of these limits.

You can work out the current it will draw.
Power = Voltage * current
so current = power / voltage
= 5 W / 24 V
= 0.208 amps
You can use a 555 to generate the pulses and then use these pulses to drive a power transistor or power FET.

Like the drawing below, except you may drive the actuator directly or with a relay as shown:

[PLAIN]http://dl.dropbox.com/u/4222062/relay%20driver2.JPG [Broken]

The problem then may be that the actuator might have trouble reacting 15 times a second.
 
Last edited by a moderator:
  • #3
vk6kro said:
A 555 would not be able to directly drive an actuator like that. They have an upper voltage limit of 18 volts and a current rating of 200 mA. In practice, you would not use more than 75% of these limits.

You can work out the current it will draw.
Power = Voltage * current
so current = power / voltage
= 5 W / 24 V
= 0.208 amps
You can use a 555 to generate the pulses and then use these pulses to drive a power transistor or power FET.

Like the drawing below, except you may drive the actuator directly or with a relay as shown:

[PLAIN]http://dl.dropbox.com/u/4222062/relay%20driver2.JPG [Broken]

The problem then may be that the actuator might have trouble reacting 15 times a second.

Hmm a BJT for this? I was thought that they have slow response time compared to FETs.

I would go for power FET then, if my assumption is right. Are power FETs a lot different from normal FETs?

Because, when I had to learn them, my material was really poor and only went so far explaining them.

So this is called actuator :D
I didn't know that. I was just given the component, I was told what it does and I was told what it is meant for.

I am going shopping for 555 timer tomorrow, so can you be more specific about this power FET so I can get that too?
 
Last edited by a moderator:
  • #4
I have some BJT transistors that work up to 6000 MHz. So, no, they are not slow at all.

FETS come in enhancement and depletion mode types and power FETS are usually enhancement mode MOSFETS.

From a practical point of view, this means that they have to have about +3 V on the gate (relative to the source) to turn them on.
This varies and some need more than 5 volts, which means you can't drive them with a 5 V circuit.

Ask at the store for an enhancement mode power MOSFET then get a big one with a built-in diode to protect against high voltages.
You may have to get insulators and a heatsink as it is probably going to get hot.
 
  • #5
vk6kro said:
I have some BJT transistors that work up to 6000 MHz. So, no, they are not slow at all.

FETS come in enhancement and depletion mode types and power FETS are usually enhancement mode MOSFETS.

From a practical point of view, this means that they have to have about +3 V on the gate (relative to the source) to turn them on.
This varies and some need more than 5 volts, which means you can't drive them with a 5 V circuit.

Ask at the store for an enhancement mode power MOSFET then get a big one with a built-in diode to protect against high voltages.
You may have to get insulators and a heatsink as it is probably going to get hot.

Thank you very much kind sir.
 

1. What is a pulsating valve-circuit?

A pulsating valve-circuit is a type of valve system that uses controlled pulsations of fluid or gas to regulate the flow through a circuit. This can be achieved through various methods, such as using a solenoid valve or a piezoelectric actuator.

2. How does a pulsating valve-circuit work?

A pulsating valve-circuit works by using a pulsating signal to open and close the valve, allowing for precise control over the flow of fluid or gas. This pulsation can be controlled through a variety of methods, including electronic signals or mechanical devices.

3. What are the benefits of using a pulsating valve-circuit?

One of the main benefits of using a pulsating valve-circuit is its ability to provide precise control over the flow of fluid or gas. This can be especially useful in applications where a constant and steady flow is required, such as in medical devices or industrial processes.

4. What are some common applications of pulsating valve-circuits?

Pulsating valve-circuits are commonly used in a variety of industries, including healthcare, automotive, and manufacturing. They are often used in medical devices such as ventilators and insulin pumps, as well as in automotive systems for fuel injection and emissions control.

5. How can I control the impulses in a pulsating valve-circuit?

The impulses in a pulsating valve-circuit can be controlled through various methods, depending on the specific system. This can include adjusting the frequency or duration of the pulses, as well as using sensors and feedback mechanisms to regulate the flow. Advanced systems may also use computer algorithms to optimize the impulses for maximum efficiency.

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