[sdiy] Saw vs Triangle Sync

[Magnus Danielson]

John Mahoney wrote:
> 
>> AH-HA!!  So, "soft sync" is Tricore sync, and "hard sync" is Sawcore 
>> sync.
>>
>> It is all crystal clear now!  (This has been confusing me for a year!)
> 
> There was a lack of clarity in my post, apparently. Pardon me while I 
> shatter your crystal:
> 
> Nope!
> 
> Soft sync is like hard sync with one key difference. Hard sync restarts 
> the wave whenever there is a sync signal, period. Soft sync, however, 
> requires the slave osc to be within a certain (variable) range of 
> resetting, anyway. The result is that soft sync tends to act only when 
> the slave's frequency is harmonically related to the master osc's 
> frequency. Somebody posted pictures once, wish I could point you to them.
> 
> I would guess that soft sync can work with either saw or tri core.

Soft-sync (in this sense) rather requires the proximity in phase of the 
oscillator to be synced to allow the sync pulse to spring into action. 
This will under certain circumstances only force some of the sync pulses 
to cause the syncing operation. It forms a very poor form of PLL action 
such that 3:2 frequency locks is achieved for instance.

A similar effect can be attained by insering the lock-in signal into the 
integrator and thus causing injection locking, which is the lock-in 
mechanism closest in relevance to the soft/hard sync.

Cheers,
Magnus - who most of the time works on keeping things in sync