Automatic soap dispenser - how do they dispense liquid soap?

[ibot]

Hi,

I am wondering how automatic soap dispensers pump the liquid soap out. I am thinking of a linear actuator pushing the regular pump 

But, these liner actuators costs around 50 bucks  So, I am hoping there might be a better way to do it [as the automatic soap dispensers in market costs around $20].

Please let me know if there are other ways to do it. I google'd for this topic and did not found much info. may be I am using wrong keywords. In case if you have links to any articles related to this topic, please let me now. greatly appreciate it !

[Jak24]

Hi,

I am wondering how automatic soap dispensers pump the liquid soap out. I am thinking of a linear actuator pushing the regular pump 

But, these liner actuators costs around 50 bucks  So, I am hoping there might be a better way to do it [as the automatic soap dispensers in market costs around $20].

Please let me know if there are other ways to do it. I google'd for this topic and did not found much info. may be I am using wrong keywords. In case if you have links to any articles related to this topic, please let me now. greatly appreciate it !

50$?? didn't know they're that expensive, i mean a simple solenoid would probably work, and they are much cheaper
(the cheaper ones cost like 5$) or you can make one yourself

Regards

Jak24

[paulstreats]

they usually use a peristaltic pump (or rolling pump).

http://en.wikipedia.org/wiki/Peristaltic_pump

 most things like soap dispensers, commercial dishwashers also dispense washing fluid with them. Great for pumping controlled doses of liquid, not so good if you need a linear actuactor.

[Soeren]

Hi,

Please let me know if there are other ways to do it.

There are lots of ways to get liquid soap out of a container, but making your own will probably be more expensive than getting a cheap one.

If you want to make the control circuitry yourself, you might wanna consider the $3.85 "Empty Soap Cartridge & Pump Set" on this page