Low-power solenoid?

[jessicabrenner]

I want to apply force for an extended amount of time (10 secs to a couple minutes) using a solenoid actuator. Unfortunately, it seems that solenoids use a lot of power when they are active. Is there a solenoid type that will only use power when switching between active and not active? There's probably a way I can do this with an external mechanism, but I was wondering if there may be commercial solenoids that have this built-in.

Thanks,
Jessica

 

[Pommie]

Have a look at model railway points motors as these do what you want but it really depends on how much force you require.

Maybe you should explain your goal rather than your solution.

Mike.

 

[jessicabrenner]

Wow, that was quick

Well, I want to apply a positive air pressure through thin flexible tubing. The pressure must be sudden, and large. One solution is to apply positive pressure to the tubing (using a CO2 tank for instance), and to use a solenoid valve (with the tubing connected to "normally closed") to allow the positive pressure to act on the tubing downstream of the solenoid valve. OR, I can use a solenoid actuator (a "push" solenoid I think) and press onto a large plastic syringe that pushes air into the tubing (thus creating the positive pressure).

Point motor looks promising, I'll look more into those. Thanks!

 

[jessicabrenner]

I just found out about "latching solenoids" but they look expensive. Anyone know of a cheap source for these or something that does something similar?

 

[Joe G]

if the tubing in flexible, why not use a small gear motor with an eccentric wheel to apply pressure ....peristaltic pump. add an optic switch or such to know where the wheel is.

 

[Reloadron]

Wow, that was quick

Well, I want to apply a positive air pressure through thin flexible tubing. The pressure must be sudden, and large. One solution is to apply positive pressure to the tubing (using a CO2 tank for instance), and to use a solenoid valve (with the tubing connected to "normally closed") to allow the positive pressure to act on the tubing downstream of the solenoid valve. OR, I can use a solenoid actuator (a "push" solenoid I think) and press onto a large plastic syringe that pushes air into the tubing (thus creating the positive pressure).

Point motor looks promising, I'll look more into those. Thanks!

Solenoids generally come in two basic flavors, intermittent (momentary) duty and continuous duty. Using a intermittent duty solenoid in a continuous duty application will result in the coil overheating and burning up. That said it sounds like you want a pneumatic solenoid to turn On/Off a high pressure air line, possibly to drive a pneumatic cylinder. Should that be the case you need a specific type of pneumatic solenoid, like a 3 way, two position type. This is because if you are charging a pneumatic cylinder when the pressure is removed the cylinder will remain charged unless the trapped air has somewhere to go.

Solenoid power consumption is a function of the work the solenoid does and yes, in some cases a continuous duty solenoid can use considerable power. It sounds like you want or need a latching pneumatic solenoid valve of sorts. You don't really mention the full scope of what you are trying to do or the power and voltages available? A Google of "latching pneumatic solenoid valve" will show you some of what is out there.

Ron

 

[cowboybob]

I want to apply force for an extended amount of time (10 secs to a couple minutes) using a solenoid actuator. Unfortunately, it seems that solenoids use a lot of power when they are active. Is there a solenoid type that will only use power when switching between active and not active? There's probably a way I can do this with an external mechanism, but I was wondering if there may be commercial solenoids that have this built-in.

Thanks,
Jessica

and

... Well, I want to apply a positive air pressure through thin flexible tubing. The pressure must be sudden, and large. One solution is to apply positive pressure to the tubing (using a CO2 tank for instance), and to use a solenoid valve (with the tubing connected to "normally closed") to allow the positive pressure to act on the tubing downstream of the solenoid valve. OR, I can use a solenoid actuator (a "push" solenoid I think) and press onto a large plastic syringe that pushes air into the tubing (thus creating the positive pressure).

If it's simply a positive pressure (rather than a positive pressure with flow), what about two momentarily actuated solenoid valves?

One solenoid valve to charge the tubing line (for as long as is needed to obtain the necessary pressure and then released) and the other valve used to release that pressure.

 

[KeepItSimpleStupid]

This might be a job for an air actuator. (e.g. a single or double acting air cylinder).

You can design a solenoid driver, e.g. injector driver that can deliver a quick pulse and then the current dies down. I had the opposite problem: I wanted to actuate a solenoid somewhat slowly and then hold it.

 

[alec_t]

You might be better using a RC modellers's servo for this. Heavy duty ones are available and are likely to be far less power-hungry.

 

[jessicabrenner]

if the tubing in flexible, why not use a small gear motor with an eccentric wheel to apply pressure ....peristaltic pump. add an optic switch or such to know where the wheel is.

Unfortunately, I don't think this can produce the result I want. I forgot to mention that there will be very limited air flow. I think a peristaltic pump won't work well in this case.

CowBoyBob, thanks for the suggestion. I think that is basically what a "point motor" is. I like the latching solenoid thing the best though.

alec_t, the problem with that is the servo will continue to consume power while trying to push the syringe or control the flow. There might be a way for it to work though.

Reloadron, thanks for your explanations, its really helpful. Your right, I don't require any flow. Yes, a latching seems to be exactly what I want. I found these: https://www.pneumadyne.com/normally-closed-latching-solenoid-valves-p-1453-l-en.html?language=en which seem decent, I'm sure there are a ton of others.

Thanks everyone!

 

[Reloadron]

Yes, the ones you linked to should be what you want. Reasonably priced also.

Taken from this data sheet.

Function
A momentary pulse lifts the internal armature opening the valve
and allowing an internal magnet to hold this position (latched)
when the power supply is removed; flow is directed through
port 1 and out port 2. The orifice to port 3 is blocked, preventing
exhaust flow.

A second momentary pulse unlatches the valve allowing the
armature to cover the orifice, blocking flow at port 1. Exhaust
flows through port 3.

So only a pulse is needed to have the solenoid change states and you get exhaust.

Have a Great Day
Ron