MOTM

I'm looking over the schematic of the MOTM-800 and wonder if a
problematic situation could arise if:

1. Something is jacked into gate defeating the false gate of R15,
 but itself not providing a gate, which would leave the release leg of
the 4066 on.

2. Attack and Release set to 0.

3. A trigger pulse occurs

It seems as though this would set up a fairly low resistance path from
15 volts to ground through the attack and release legs of the 4066.  Is
this not so?  Or is the voltage at C9 and Th provided by the divider
made up of the 2 legs enough to then turn off the attack leg via the 555?

Dave Moylan

The only path to ground is through U1A.  For this switch to be on, the 
control must be high and hence the gate must be low.  If the gate is 
low, the 555 is reset, so Q is low and U1C and U1D are off.  The gate 
low also disables U1B.  There is no source, just sink, and trigger 
won't do anything since the 555 is reset.

Dave

--- In motm@yahoogroups.com, David Moylan <dave@...> wrote:
>
> I'm looking over the schematic of the MOTM-800 and wonder if a
> problematic situation could arise if:
> 
> 1. Something is jacked into gate defeating the false gate of R15,
>  but itself not providing a gate, which would leave the release leg 
of
> the 4066 on.
> 
> 2. Attack and Release set to 0.
> 
> 3. A trigger pulse occurs
> 
> It seems as though this would set up a fairly low resistance path 
from
> 15 volts to ground through the attack and release legs of the 4066.  
Is
> this not so?  Or is the voltage at C9 and Th provided by the divider
> made up of the 2 legs enough to then turn off the attack leg via the 
555?

> 
> Dave Moylan
>

That's what I was missing.  Thanks Dave.

Dave

djbrow54 wrote:

> 
> 
> The only path to ground is through U1A. For this switch to be on, the
> control must be high and hence the gate must be low. If the gate is
> low, the 555 is reset, so Q is low and U1C and U1D are off. The gate
> low also disables U1B. There is no source, just sink, and trigger
> won't do anything since the 555 is reset.
> 
> Dave
> 
> --- In motm@yahoogroups.com <mailto:motm%40yahoogroups.com>, David
> Moylan <dave@...> wrote:
>>
>> I'm looking over the schematic of the MOTM-800 and wonder if a
>> problematic situation could arise if:
>>
>> 1. Something is jacked into gate defeating the false gate of R15,
>> but itself not providing a gate, which would leave the release leg
> of
>> the 4066 on.
>>
>> 2. Attack and Release set to 0.
>>
>> 3. A trigger pulse occurs
>>
>> It seems as though this would set up a fairly low resistance path
> from
>> 15 volts to ground through the attack and release legs of the 4066.
> Is
>> this not so? Or is the voltage at C9 and Th provided by the divider
>> made up of the 2 legs enough to then turn off the attack leg via the
> 555?
>>
>> Dave Moylan
>>
> 
>