Improved Triac circuit

* Theoretical analysis: up to 6:14min
* Practical analysis with oscilloscope: 6:14 to 13:09.
In this video, we discuss how the phase shift between the input voltage and the timing capacitor introduces a hysteresis when the circuit operates at high phase angles (lowest dimming settings). This can cause flickering as the phase angle timing may be wrong or missed. In addition, when the dimmer is started, a 'pop' effect is often seen, where the circuit does not start until the phase angle is reduced and then increased again, for example where a bulb brightness must first be increased at turn on, before it can be reduced to the lowest settings.
The circuit comprises a method to remove any residual charge from the timing capacitor at each zero crossing, so as to give the circuit an accurate starting time base, at every phase angle of operation
The Video covers the detailed explanation of the circuit, together with a practical overview of the produced waveforms, including a comparison between the generic circuit and the new improved version.

[@sumitbiswas1078]

Thanks for you

[@carmelpule6954]

This is an excellent circuit, The Diodes seem to cater for the peak of the 120 Volt supply and 600 Volts is being extra safe.
The capacitor C! at 7:42 is shown as an electrolytic but this C1 has to accept both polarities.
A good idea and it provides a great improvement to the unit.

[@eugenepohjola258]

Howdy.
Absolutely great.
Regards.

[@luisrojo6338]

Excelente, saludos from México

[@kattaylor5741]

Although not explicitly indicated with a + sign, the capacitor symbol shown is typical of a polarized capacitor.

[@tommymorton4939]

Where can I see the final schema?
Also can it be adopted for 230V mains?

[@chbonnici]

But what about with 240Vac input

[@alilatifovic1628]

Electrolytic cap charged to -20v ? On your pcb can't see the c1 (electrolytic one)

[@dinhcao7528]

Which circuit can be used for 240v?

[@alexanderzohrens2945]

Which threshold-value does D5 have?

[@drewhalliday8531]

Does it matter where you put the load?

[@computermaster360]

It sure does, just ask your dad

[@computermaster360]

Now to answer your question in seriousness, no it does not. You can put it at the "top", as shown at 3:57 (conected to the resistors R2, R4 and R3), or at the "bottom" (connected to D2, C1 and D4). It also does not matter whether the top AC terminal is live and bottom is neutral or vice versa, since the input is (typically) just a symmetrical sinusoidal AC wave.