1
\$\begingroup\$

I'm selecting some solenoids with my MechE and I noticed something that I didn't have an intuitive explanation for.

We were looking at this solenoid and noticed that at the bottom the forces available were higher when used with intermittent pulsing instead of continuous pulsing. We haven't been able to explain to ourselves why this is the case. Any guidance?

\$\endgroup\$

1 Answer 1

3
\$\begingroup\$

You are missing the fact that the bottom lines are for the two different types.

enter image description here

Figure 1. The yellows are related. The blues are related. [Colouring mine.]

The problem with solenoids is thermal management. The intermittent units have resistances of one quarter that of their continuous counterparts and a power consumption (and dissipation requirement) of four times that of the continuous.

The intermittent solenoid therefore can give a little over three times the force of the continuous units but only for 5 s at a time. 25% duty cycle implies that you'll need to wait 15 s after a 5 s on time before retriggering.

\$\endgroup\$
4
  • \$\begingroup\$ Jesus. That's so obvious. Thank you. I don't know where my head is. Thanks thanks. \$\endgroup\$ Aug 31, 2018 at 15:54
  • \$\begingroup\$ That's not my name. He's a friend of mine. \$\endgroup\$
    – Transistor
    Aug 31, 2018 at 16:37
  • \$\begingroup\$ Furthermore, note the middle two rows are actually the same solenoid. On 12V, you can run it continuously. On 24V it takes 4x the power which is only safe for 5s. But it's not surprising that 24V produces higher force... \$\endgroup\$
    – user16324
    Aug 31, 2018 at 18:30
  • \$\begingroup\$ Thanks, @Brian. I missed that in a case of only seeing what I was looking for. \$\endgroup\$
    – Transistor
    Aug 31, 2018 at 18:32

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.