[GreenKeys] GreenKeys Digest, Vol 110, Issue 61

[John Nagle]

On 3/17/2013 11:10 AM, greenkeys-request at mailman.qth.net wrote:
> In a message dated 3/17/2013 10:08:55 A.M. Mountain Standard Time,  
> gil at baudot.net writes:
> 
> Hey folks:
> 
> 
> I think I finally found a cost-effective gizmo for tty motor power -- the  
> PowerSwitch Tail II
> > Only 26 bucks and worldwide versions available.  Not UL-listed, but
 the
> PCB looks like a safe layout (peek at the kit, but buy it  assembled).
> To get a UL-listed relay like this from a place like russound or xantech  
> will cost about 100 bucks.

   The kit shows an electromechanical relay driven through an
optoisolator.  No sign of strain relief on the power cord.
Only the solder connections to the board hold it on.  The
Tail II, though, is longer, and has visible strain reliefs
on the cords.  (Probably because version 1 shorted out.)

   Solid-state relays are getting cheaper.  See

	http://www.futurlec.com/Relays/SSR10A.shtml

for a standard encapsulated screw terminal hockey puck for
chassis mount.
Manufactured by Xiamen Hongfa Electroacoustic Co., Ltd.,
in Fujian province.  Switches 10A 120VDC.  $9.90 each.
UL approval E133481, and it checks with the UL database.
Mount to a metal chassis for heat dissipation.

Comparable to Crydom CSW2410-10, which is $33.47 from Digi-Key,
or Omron G3NA-210B-DC5-24. at $27.00.  Those are also available
surplus, for lower prices.

   Go with a UL approved part for this.  UL will have tested that
it won't catch fire if shorted.

				John Nagle