Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
Capacitive Sensor addon
- Thread starter DFisch
- Start date
Haven't seen this and could use some more details about your application such as what you are measuring and how but a couple of options:
- Reference capacitor at ambient temp to control for temp at sensor
- Some sort of proximity switch
Are you sure it is in series?
- Reference capacitor at ambient temp to control for temp at sensor
- Some sort of proximity switch
Are you sure it is in series?
- Thread starter
- #3
It is definitely in series - no doubt there.
It may be a solenoid proximity switch, if so not like any I have ever seen.
The application is above an ink tank, the sensor(s) see a high/low level and fill the ink tank back up.
The valve opens up to fill the tank at 50mm from the sensor, and stops filling at 20mm from the sensor.
This makes me think it must be 2 sensor operating here, since a capacitive wouldn't get 50mm distance unless it was far bigger.
Are there any openings or windows on the aluminum block?
Could it be an overflow cutoff switch in case of main sensor error? If this is the case it could be magnetic, thermal, ultrasonic, conductive, etc depending on the properties of your ink. You could test it by submerging it in ink and seeing if anything happens.
Could it be an overflow cutoff switch in case of main sensor error? If this is the case it could be magnetic, thermal, ultrasonic, conductive, etc depending on the properties of your ink. You could test it by submerging it in ink and seeing if anything happens.
- Thread starter
- #5
There are no openings or windows in the block.
This was sent to us by a client, who also does not know what it is, just that it no longer works. I don't have access to the factory, if I did this would be much much easier.
The parameters I was given is that it activates (fills the tank) at 50mm from the sensor(s), and de-activates (stops filling) at 20mm from the sensors.
The arm sits above the tanks.
My first thought was why not have one sensor inside the tank, but this does not work because it is used on different inks, colors, etc.
A capacitive sensor has only 2 states, on or off, so this other little block must be a sensor of some sort - just no idea what.
The capacitive would do the 20mm "top" end of the open tank, so this other sensor would do the lower end, 50mm sensing distance.
I don't think it would be magnetic or thermal. Ultrasonic is a possibility, the sensing distance works, but I don't see how such a closed box could be ultrasonic.
This was sent to us by a client, who also does not know what it is, just that it no longer works. I don't have access to the factory, if I did this would be much much easier.
The parameters I was given is that it activates (fills the tank) at 50mm from the sensor(s), and de-activates (stops filling) at 20mm from the sensors.
The arm sits above the tanks.
My first thought was why not have one sensor inside the tank, but this does not work because it is used on different inks, colors, etc.
A capacitive sensor has only 2 states, on or off, so this other little block must be a sensor of some sort - just no idea what.
The capacitive would do the 20mm "top" end of the open tank, so this other sensor would do the lower end, 50mm sensing distance.
I don't think it would be magnetic or thermal. Ultrasonic is a possibility, the sensing distance works, but I don't see how such a closed box could be ultrasonic.
I'd guess the yellow one is ultrasonic for that distance.
Alternatively, one is an infrared light source and the other is a receiver.
Keith Cress
kcress -
Alternatively, one is an infrared light source and the other is a receiver.
Keith Cress
kcress -
Setting aside the question of what it is, you can accomplish the job of both with a single ultrasonic sensor like one of these:[URL unfurl="true"]http://www.instronics.com/Migatron_RPS401.html[/url]
Is it good enough to replicate the function or has your customer asked you to duplicate the setup?
Is it good enough to replicate the function or has your customer asked you to duplicate the setup?
Looking at all the rest of that hardware are you sure the mystery sensor isn't a proximity sensor that detects metal as the arms maybe fold up? That would tell the system not to do something when folded??
Keith Cress
kcress -
Keith Cress
kcress -
- Thread starter
- #11
- Status
Similar threads
- Locked
- Question
- Locked
- Question
- Locked
- Question
- Locked
- Question