I got this component from someone clearing out their garage. At first I thought it was a solenoid but the ‘pin’ section doesn’t move and there is no spring on the outside of the component.

I haven’t had a chance to ask a professional or to hook it up to power, but I was hoping it could be identified. The component has no identifiable markings or writing, and after checking the print on the wiring it is specifically about the wire not the component. See pictures attached.

Any help would be appreciated.

item picture 1 item picture 2

  • \$\begingroup\$ Might be a small pump of some kind - the "pin" seems to be a tube, and there is a vent type thing on the other side. Alternatively it could be a solenoid with an actuator inside the tube. \$\endgroup\$ Nov 18, 2017 at 18:21
  • \$\begingroup\$ Have you measured resistance between the two pins? If it seems to be a resistance, you could try connecting it to a single AA battery momentarily and see if anything happens. \$\endgroup\$ Nov 18, 2017 at 18:22
  • \$\begingroup\$ Maybe an electromagnet if the pin is fixed. \$\endgroup\$
    – Trevor_G
    Nov 18, 2017 at 18:30
  • \$\begingroup\$ @TomCarpenter Don’t have a multimeter on me so I just stuck the wires on a battery - nothing happened. At all, no noise, no movement, nothing. Maybe it’s busted or the AA just isn’t enough to get it going? \$\endgroup\$ Nov 18, 2017 at 18:32
  • 2
    \$\begingroup\$ Looks like a shaded pole AC solenoid something like the water pumps used in expresso makers using a spring loaded diode pumped current to make a water pump oscillating at line frequency and very noisy. But given the air intake its possibly an air pump for aquarium tanks. ( Am I close in my guess?) \$\endgroup\$ Nov 18, 2017 at 18:49

1 Answer 1


It's a solenoid air valve, used in blood pressure meters. Here's another example:-

enter image description here

enter image description here


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.