why are centrifugal switches used by Sentry?

[justie1220]

I know that they are used for Sentry's single phased units but why when ASC and Federals single phased units old and new never had to? Is there a benefit for using them or is it how their single phase sirens are made? :crazy:

[JasonC]

Sentry uses capacitor-start motors. New Federal's and ASC sirens actually have DC motors that have a rectifier in their controllers to convert the AC into DC. Model 2 sirens have universal motors (hence the brushes) and many older sirens used the repulsion type motors (which aren't really made anymore).

Read this for a good comparison of AC motors:

http://en.wikipedia.org/wiki/AC_motor

[Tyler]

Sentry uses capacitor-start motors. New Federal's and ASC sirens actually have DC motors that have a rectifier in their controllers to convert the AC into DC. Model 2 sirens have universal motors (hence the brushes) and many older sirens used the repulsion type motors (which aren't really made anymore).

Read this for a good comparison of AC motors:

http://en.wikipedia.org/wiki/AC_motor

That reminds me, does the B Series Thunderbolt use a repulsion motor?

[Antiwhoknows]

The B Series used a universal series motor too, but was enclosed and more streamlined. Here's a picture from the siren projects part of the ARS website.

[holler]

The old single phase ACA sirens used an external voltage sensing relay for the start winding.

[justie1220]

That answers my questions thanks guys!

[Tyler]

The B Series used a universal series motor too, but was enclosed and more streamlined. Here's a picture from the siren projects part of the ARS website.

Ok my second question. Which was better in the Thunderbolt Repulsion or Universal.

[Antiwhoknows]

They were all universal motors for Thunderbolt chopper motors and Model 2s. Universal motors are similar to repulsion motors (they both use commutators and brushes) but can work on AC or DC power. Repulsion motors only work with AC.

[Tyler]

Oh ok.