I am designing a failsafe system for an Unmanned Aerial Vehicle, and it needs to be able to switch 6 PWM outputs from one source to another. My initial thought was to use a series of logic level relays but they cannot fulfill all the requirements that I have listed below, what are some alternative methods I can use?

  • Survive intense vibration (~.3G at 300-600Hz)
  • Fail safe, in the event of a total loss of power the signals will flow without impediment
  • Listed MTBF or MCBF (hoping for around 1,000,000 Hours or 100,000 Cycles per channel)
  • \$\begingroup\$ Not even latching relays? \$\endgroup\$ – Ignacio Vazquez-Abrams Sep 21 '15 at 19:53
  • \$\begingroup\$ The problem is that if it is latched in the wrong position they won't revert to the Failsafe position after the loss of power \$\endgroup\$ – Mark Omo Sep 21 '15 at 19:55
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    \$\begingroup\$ Ah, now I understand what you mean by "in the event". \$\endgroup\$ – Ignacio Vazquez-Abrams Sep 21 '15 at 19:56
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    \$\begingroup\$ What's generating the PWM when there is no power? Can your switches be powered by the same source for the PWM? \$\endgroup\$ – Arsenal Sep 21 '15 at 19:58
  • \$\begingroup\$ I don't consider 0.3G to be intense vibration. Pretty much any relay on the market today will have absolutely no problem with that level of vibration. \$\endgroup\$ – Dwayne Reid Sep 21 '15 at 20:00

The IXYS LCC120 is a solid-state OptoMOS relay with a Form C (SPDT) contact. It can switch up to 170 mA with a maximum on resistance of 20 Ω (16 Ω typical).

The datasheet has no spec on vibration but I can't believe that would be a problem with solid state relays. Available from Digi-Key.


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