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 !