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Four dimming circuit performance analysis

Published on Mar 15 2011 // Integrated DIY circuits

Four dimming circuit performance analysis.

This dimming of several stochastic analysis of the performance of the circuit.
Called the Stochastic Dimming, that is, when the INPUT Trigger Signal, regardless of the direction of the Supply Voltage, the pressure value of How, immediately Turn the load. In the Zero at the Turn-off. It is by Changing the conduction Angle to SCR Dimming. Figure 1, 2, 3, 4 are Random-type Dimming Circuits.
Figure 1 is a Simple Dimming Circuit. The Advantage is that less Components. Only three. RESISTOR R is the Current limiting to prevent the newly energized, due to a Low resistance on the RP. Damage due to excessive Current Components. Although the Circuit is the most Simple. But the disadvantage is also the most. First, the Selection of RP Circuit. Because different types of SCR, the Trigger Current is also different, especially the different Current SCR, Triggering the Current difference in the times above. When the Trigger Current of the SCR using different Time, RP’s resistance should also be different in order to Obtain a Better Adjustment Range; Second, there is bidirectional Voltage Inconsistencies. This phenomenon appears in more than 50% of the Power Range. Closer to 50% Power at the more apparent. When less than 50% or even a single Wizard-Pass phenomenon. These phenomena are caused by the Silicon itself. Because of its two-Way BI-directional SCR Trigger Current inconsistency of Evil to guide a Small Pass, after the Big Turn, when the Great Evil to the Peak Voltage Turn on Time can not. Became unilateral Connecting. This is a common problem triac, because its can not be consistent Trigger Current, IT is difficult to overcome the shortcomings; Third Flicker. At 50% Power at the Serious Flashes. This is because the Trigger Current to the Big Jesus, only to Turn the Voltage Peak. Fluctuations in the Electric Smell of Mutton, Subtle changes occur SCR Trigger Current instability factor, the SCR off when a Forward Pass result. There are also Flashes in Low Light. Figure 1 also has the Advantage Enough that the resistance is large when the RP, no need for the Power Switch, Turn off the Lights when the Dark until the Light Goes Far raised the most out SO . The Circuit in Figure 2 can be Smaller RP.
In addition to more Foreign Components in Figure 3. Its Advantages and disadvantages as shown in Figure 1. Components of the Circuit Parameters to Meet the appropriate order to Obtain Better Results. When you CHANGE the Parameters of one of the Components, Components of the other Parameters to be adjusted, is the Production of the most difficult Circuits. The Circuit, such as Silicon with one-Way (from full-Wave Rectifier Power Supply), you can reduce the Voltage Dual Wizard Wizard inconsistent or single-Pass phenomenon, only Light in Low-Pass Wizard with a single phenomenon, the phenomenon is not caused by SCR, but caused by the Circuit itself. Because of the load Voltage is Always in the K Pole. K is equivalent to a Great Series resistance, SO that the trigger voltage increases.
Because of the circuit through the phenomenon of a single guide, so not suitable for speed control.
Figure 4 is the Ideal Circuit. It does not Flash, there is no single guide or two-way asymmetric links (unless DB3 trigger voltage asymmetry.) The circuit performance, the most stable. So commonly used in speed. It does not exist select SCR problems, so it can be different from current SCR. Unless the trigger current is too great, to provide the instantaneous capacitor current can not make it turn, and if so, can only increase the capacitance to increase the trigger current (RP should be reduced, so as not to affect the adjustment range.)