remote switch

[olinn]

I don't know whether or not it is appropriate to ask here. I want to programmably remote switch on/off a He compressor cryostat machine. I plan to take apart the front panal of the machine, disconnect the circuit behind the "start" button and insert a programmable remote switch device.

Is it the right way to do the job? Anyone knows the remote switch that has a computer compatible interface. Thank you so much!

 

[itsmoked]

With the little info you have provided it is too large a field to 'guess' into.

What is the voltage across the switch? Is the first tidbit that is required.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[olinn]

sorry for the confusion! I don't know this field at all. I am doing some GPIB control for some electronic devices currently, but find the only thing in my whole setup up I cannot remote control is this cryostat.

The crystat is an old APD cryogenics. it uses a 208V voltage source and I don't the power (I cannot find the manual for it).

I don't turn it on and off very often. so I don't care about the speed. I just want to turn it off automatically when it cool the chamber to a specific temperature which is read from the thermal sensor.

thanks again!

 

[itsmoked]

Well like I say we can't help you until we know what you're trying to switch. If it's line voltages then you need something other than then if it's a logic control.

If you are going to do this then you need to pull the cover and measure the voltage across the contacts when the machine is off and on.

Also it would be good to measure the current across the switch,(while it's off), with an ammeter across it, (which should turn it on).

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[jonesy29847]

Rockwell makes Ethernet Contact outputs we used those where we had to interface with a fire suppression system in onr of our plants. Without knowing what kind of PLC you are using it is not possible to be specific.

Generally speaking if you don't know what voltage you are interfacing with, or if your power supplies are not common, a contact output module of some type will do the job, just be sure you are within the contact current ratings.

Typical voltage ratings are 250 VAC at about 1 A. More likely than not you are dealing with a pilot circuit and you shpuld be OK.

As far as measuring current, you can just get the current ratings of the circuit you are driving from the manufacture.

Itsmoked suggestion might be a little hard to do as the reading will be very transient in nature, you may see the pull in current but then the meter will go to zero. The ammeter should be in series with the circuit you are looking at to get the reading you desire.

Regards

 

[itsmoked]

Across the switch is in series with the circuit!

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[jonesy29847]

Yes you are right, my mistake.

 

[itsmoked]

I think he was electrocuted anyway...

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[jonesy29847]

LOL