[Hallicrafters] vibrator how it works

[Gary]

If you have access to a few old Sams photofacts with car radios, the
vibrator circuits are pretty simple to understand.
Gary...WZ1M
----- Original Message ----- 
From: "William L Howard" <wlhoward at verizon.net>
To: <hallicrafters at mailman.qth.net>
Sent: Sunday, April 15, 2007 3:41 PM
Subject: [Hallicrafters] vibrator how it works


> vibrator how it works
>
> For anyone who wants to make a demonstration vibrator unit, I took a Radio
> Shack 12 volt relay and wired one set of contacts to act like a door
buzzer
> and the other set was wired to the secondary of a Radio Shack Transformer.
> This vibrates too fast for the second contact to make contact with the NO
> position so I added a capacitor across the relay coil winding which holds
it
> closed long enough to make contact with both sets of contacts. The
> transformers 115 volt primary, now being used as a secondary puts out an
AC
> current much higher than the original 12 volt input. I then ran this
through
> a voltage doubling circuit.
>
> Be prepared for some very strange voltage readings!
>
> Bill Howard
>
> ______________________________________________________________
> Hallicrafters mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hallicrafters
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:Hallicrafters at mailman.qth.net
> ----
> List Administrator: Duane Fischer, W8DBF **for assistance**
> dfischer at usol.com
> ----
> Hallicrafters Collectors International: http://www.w9wze.org
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.446 / Virus Database: 269.4.0/761 - Release Date: 4/14/2007
9:36 PM
>
>