[ARC5] TCS Transmitter Tip

[Scott Robinson]

Another way to speed up the relay is to put a capacitor across the coil. 
You chose the cap value to limit the peak voltage to something safe, by 
measurement. I'd start with 0, 1 uF. Smaller cap = higher voltage = 
faster opening.

I have done this in commercial products fro 30 years; it works fine.

Peace,

Dcott

On 11/25/16 10:15 AM, Dennis Monticelli wrote:
> Decreasing the lag time on break is very easy to accomplish.  Simply
> putting a zener in series with the diode will dramatically reduce the
> lag by rapidly collapsing the magnetic field.
>
> Dennis AE6C
>
> On Fri, Nov 25, 2016 at 8:57 AM, Michael Hanz <aaf-radio-1 at aafradio.org
> <mailto:aaf-radio-1 at aafradio.org>> wrote:
>
>     It depends completely on the systems implications, Wayne.  A
>     straight diode will add a significant time (milliseconds) to the
>     contact break time, depending on the strength of the magnetic field
>     in the pole and the air gap between the pole piece and the moving
>     armature.  If it's just a push to talk function, it might be
>     permissible.  If it's a telegraph key follower, you may be in
>     trouble from a speed standpoint.  There is an  annoying lag-on-break
>     in that case.
>
>     73,
>     Mike  KC4TOS
>
>     On 11/25/2016 10:24 AM, Robert Eleazer wrote:
>>     Isn't it modern practice to put a solid state diode across relay
>>     DC energizing coils?  Given electron tubes' higher voltages and
>>     thus their resistance to spikes do we not need to worry about that?
>>
>
>
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