Power switch on-off Timer?

[OAC]

I've laborate with my pumps over the years and came to the conclusion(which was obvios from the beginning... )that I should let the pump run continously. I can see your point with heat thou...but can't you just install a fan or something to cool it of? I have the opposite problem. I let my pumps run 30min, or so, before pressing to get them warm.

I also did the atmospheric pressaure meassure with Arduino. Since I draw full vacuum thru the whole pass it was just....nerdy.

[sammer]

Easy enough to build one of these.
http://www.joewoodworker.com/veneering/EVS/concept.htm
I bought the controller and used it a few times but I think it developed a leak in the diaphragm or whatever it uses to sense vacuum, stopped working and was a leak in the system so I just went continuous.
Vacuum pump runs 8-12hrs no biggie.
I keep my pump outside and run a hose into the shop, heat is not really an issue.

sam

[dbabicwa]

Thanks guys!

How is not a biggie?! The cost of electricity in the US might be low just like gas, but I live Australia:) Nothing cheap here.

I keep my pump near our bedroom window since live in an apartment. Which is no good since as I understand a fridge pump spits oil in the air we breath:(

All projects doing in laundry on this scorching heat. Hence using slow epoxies. Last fast epoxy almost burned in flames. That is how hot gets here.

Cheers

D.

PS
This is my pump:

[amidnightproject]

Cheers for that!

I would need a power supply = more things to move around etc. Hate to over complicate things, when one even mechanical device can do. But which one? That is a question.

See this little Belkin device: http://www.ilcnsw.asn.au/items/9882

No on/off intervals tho.

I don't think you'll find a strictly mechanical device. It'll need power to run some form of logic.

A power supply isn't a big deal. You can run any of those logic boards for days off a 9volt battery or 4 AA batteries. The total footprint of that little project would be about the size of a credit card and probably 2cm tall. The whole thing would fit inside your nifty pump carry box. Plus you are already running power to your vac pump so you could just run a 5v wall wart to power the logic board.

I think you'll be hard pressed to find something easy and cheap for this. The other option as stated before is to just use a programmable PID and a relay. Bango bongo done.

[sammer]

The controller in the joewoodworker link cycles your vacuum pump on and off.
It's a pressure switch, Strictly mechanical, open and closes the circuit. Wire it to a relay or just inline with your pump.

http://www.veneersupplies.com/products/ ... 8-NPT.html

It's not hard to build, and the controller is relatively cheap (buy two so you have a spare)They are pretty little and mail to OZ wouldn't break the bank.
Joes plans are pretty bomber, he really knows his stuff.

I know about the oil mist from vac pumps that's why mine is outside.
Fridge pumps can run continuously for years if they don't run out of oil.
My old deep freeze (found it in a garbage pile one day) had a buggered thermostat and ran constantly, would still be running today but it seeped enough refrigerant out over the 25+yrs and now it doesn't work. Pump still purrs though.
Probably didn't cost more for electricity than the 3 computers that run 24/7 in my house.

What about keeping your pump inside and venting it outside, A/C in your apartment will keep it cool enough.
Just don't make your vent hose too long or it will affect your vacuum (too much back pressure)

Just some thoughts...

sam

[dbabicwa]

@Amid, thanks, that makes more sense. I was under impression your device needed 12V, hence power supply.
Yeah, might go this route if nothing else.

@Sam, the pump is wired to an micro switch and vac advance mech. device, no probs with that. I can set any vacuum with a switch. Also running a fan sometimes (than it's loud and we can't sleep). Pump is quiet when running but loud when starting, just like any fridge.

Every pump draws more Amps on a startup, even 6+A. An rotary pump can even draw 15A on a startup. That is a lot of power if on/off all the time, like every min or so.

Hence, my vac table has got a one way valve or check valve (no pump running constantly).
Pump would drop a vac sometimes on a quick release connector but vac table would keep it.

A timer would top up a vac once/twice per hour.

[sammer]

dbabicwa...
I'm still not understanding, you lose vacuum and need the pump to run occasionally to get back to full vacuum.
So why would the switch I linked to not work for you? you could adjust it to turn your pump back on when you've dropped 3 or 4 inches of mercury, and when it gets back to 25inhg it will turn off again.
Rather than arbitrarily setting a time you could set a pressure, and keep it there within 1-2inhg.
For that matter why doesn't your vac advance/microswitch system do this already?
Depending on the spring and switch adjustments you should be able to maintain vac within 1-2inhg.
Is it monitoring the line to your table or is it on the table side of the check valve?
Maybe I'm missing something?
When my controller was running, my pump would come on every 1/2hr or so for a minute or so.
I have a pretty big (6cfm) rotary pump and I ran it straight off the switch, was gonna put in a relay but never got around to it.

sam

[dbabicwa]

dbabicwa...
I'm still not understanding, you lose vacuum and need the pump to run occasionally to get back to full vacuum.
So why would the switch I linked to not work for you? you could adjust it to turn your pump back on when you've dropped 3 or 4 inches of mercury, and when it gets back to 25inhg it will turn off again.
Rather than arbitrarily setting a time you could set a pressure, and keep it there within 1-2inhg.
For that matter why doesn't your vac advance/microswitch system do this already?
Depending on the spring and switch adjustments you should be able to maintain vac within 1-2inhg.
Is it monitoring the line to your table or is it on the table side of the check valve?
Maybe I'm missing something?
When my controller was running, my pump would come on every 1/2hr or so for a minute or so.
I have a pretty big (6cfm) rotary pump and I ran it straight off the switch, was gonna put in a relay but never got around to it.

sam

Ok, sorry about the confusion, but it's simple.
Check valve is on a table with a quick release on a hose. Disconnect a quick release and all good on a table, keeps a vac.

But quick release seal is not perfect so the pump side vac drops. Or, a vac advance as you said not sealed. Or pump seal not perfect. Or...

In theory no need for a switch and vac advance ie. vacuum a table which has got a check valve and that is it. If is well sealed, fine. We can vac it with a hand pump:)

But how to top it than on some intervals? As you said every 1/2hr?

Other than flick it on/off manually? That is a problem. If a table is well sealed but a pump is not, it will run every minute. Which draws a power.

[skimann20]

I forgot to respond my info, sorry. This is what you are looking for:

http://www.ebay.com/itm/like/350835467630?lpid=82


Part number is: 06-662-7

[sammer]

If your switch is monitoring your table it will maintain the vac there and run your pump when it needs to.
Sounds like you just need to move the port feeding your switch.

sam

[dbabicwa]

If your switch is monitoring your table it will maintain the vac there and run your pump when it needs to.
Sounds like you just need to move the port feeding your switch.

sam

Whoa!!! Excellent idea! Thanks

[dbabicwa]

I forgot to respond my info, sorry. This is what you are looking for:

http://www.ebay.com/itm/like/350835467630?lpid=82


Part number is: 06-662-7

Thanks! Multiple timers. Even better!