Workings of a vacuum sealer and help identify a mysterious component - Page 1
Forum section: electronics / general

author: Yamin
author_rank: Frequent Contributor
timestamp: December 16, 2018, 08:23:29 pm
content: Hi I opened up one of those food vacuum sealer machines - it has got the function of sealing things stored in a bag or it could seal things in a jar/bottle.I was hoping to get some help figuring out on how it works. I thought it was going to be pretty straight forward with a motor sucking the air out like a vacuum cleaner - there is a motor with the pipes connected to the vacuum channel (where the bag mouth is placed). However there is also another pipe going from vacuum channel and which splits one end goes into the bottle/jar inlet and then it goes into a mystery component, the pcb marking says "K1". It looks like a motor it has got a small hole. It needs a voltage across its terminals.I have attached some pictures and a rough sketch of the vacuum lines.I hope to understand the mechanics behind how the vacuum sealer works. Thanks in advance.

author: daqq
author_rank: Super Contributor
timestamp: December 16, 2018, 08:33:16 pm
content: Pretty sure that K1 is a simple pressure switch. Not a sensor, just a simple mechanical contact.

author: eb4fbz
author_rank: Regular Contributor
timestamp: December 16, 2018, 08:41:31 pm
content: That's the pressure switch that stops the vacuum pump when it's done.

author: Mr.B
author_rank: Unknown
timestamp: December 16, 2018, 08:44:51 pm
content: Quote from: daqq on December 16, 2018, 08:33:16 pmCorrect.The one I own is almost identical.Once the air is (mostly) removed from the bag, the sensor activates.This turns on the heater elements for a set period of time to seal the bag.After timeout, the heater elements and the pump turn off.My one also has a second time period after this where a red LED stay illuminated for approximately 7 seconds.This 7 seconds is to alow the heater to cool and therefore the sealed bag to cool before attempting to remove.

author: Yamin
author_rank: Frequent Contributor
timestamp: December 16, 2018, 09:27:25 pm
content: Ah I see, thanks for the clarification. Is there anyway to activate the pressure switch manually? - earlier I tried blocking the end of the pipe with my finger to see whether there was a change in the motor, the motor didn't stop.Just thought of some more questions -1.Why is the pressure switch in line with the bottle/jar inlet?2.What happens if a bottle/jar is not connected and when the machine sucks air from the bag wouldn't it also be sucking thorough the bottle/jar inlet? It clearly doesn't but how does it achieve that?Again really appreciate your guys help

author: Mr.B
author_rank: Unknown
timestamp: December 16, 2018, 11:05:57 pm
content: QuoteYou would need to test (with a multimeter or continuity tester) if the switch was normally closed or normally open (when the unit is powered off).If it is normally open, a small push button with short lengths of wire could be added across the switch solder joints.If normally closed, a bit more work is required, but it is fairly easy if you have the right tools.Quote1. To allow it to depressurize the container you connect it to. The *bag lid* must be closed during this procedure.2. In my unit, the bottle/jar connector has a shutoff valve that is only opened by inserting the spigot of the bottle/jar attachment - a separate piece of equipment.