Re: Aw: Re: AW: Re: [EVGRAY] Low Lenz in plain sight

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Half Wave Phase Control

thyristor half wave phase control circuit

 

Phase control is the most common form of thyristor AC power control and
a basic AC phase-control circuit can be constructed as shown above. Here
the thyristors Gate voltage is derived from the RC charging circuit via
the trigger diode, D_1 .

During the positive half-cycle when the thyristor is forward biased,
capacitor, C charges up via resistor R_1  following the AC supply
voltage. The Gate is activated only when the voltage at point A has
risen enough to cause the trigger diode D_1 , to conduct and the
capacitor discharges into the Gate of the thyristor turning it “ON”. The
time duration in the positive half of the cycle at which conduction
starts is controlled by RC time constant set by the variable resistor, R_1 .

Increasing the value of R_1  has the effect of delaying the triggering
voltage and current supplied to the thyristors Gate which in turn causes
a lag in the devices conduction time. As a result, the fraction of the
half-cycle over which the device conducts can be controlled between 0
and 180^o , which means that the average power dissipated by the lamp
can be adjusted. However, the thyristor is a unidirectional device so
only a maximum of 50% power can be supplied during each positive half-cycle.

There are a variety of ways to achieve 100% full-wave AC control using
“thyristors”. One way is to include a single thyristor within a diode
bridge rectifier circuit which converts AC to a unidirectional current
through the thyristor while the more common method is to use two
thyristors connected in inverse parallel. A more practical approach is
to use a single *Triac* as this device can be triggered in both
directions, therefore making them suitable for AC switching applications.


On 7/31/2018 9:32 AM, [email protected] [EVGRAY] wrote:
>  
>
> Hi Ole
>
> The sinewave peak detector circui of Ron Pugh I just put up link to
> circuit works on this zero-cossing idea I am pretty sure...he put the
> circuit together from info he found on the net and I think this is the
> same idea you have...here is link again to Rons circuit (which works
> very well...third chip is oscillator to chop it if you want to, bypass
> via J3 wire)
>
> https://sites.google.com/site/alternativeworldenergy/sinewave-peak-coil-shorting-circuits
>
> Kone
>
>
>