Stepless triac dimmer with a steady light function
Posted on Mar 28, 2007 6639
Circle S2 is stable automatic light switch, when S2 is open, the entire circuit is Subsection II SCR stepless presentation dimmer, simply omit the high-frequency filter circuit
, and the trigger diode switch neon bubble V, adjust potentiometer RP1 may vary depending on the brightness of the lamp is seeking to adjust the heart H, then V can emit red neon glow bubble, can serve as indicator role, this time electric road do not have stable light function. Automatically when needed steady light, you can press the switch S2, at this time the resistance (R2 + RP2 + RG) and capacitance C in parallel with it (RI + RP1) together determine the charging rate of the capacitor C. Charge rate on the one hand by the capacitance C (Rl + RPl) decision, so the resistance is still described as adjusting brightness RPI section H of the lamp; charging rate of capacitor C and by (R2 + RP2 + RG) branch influence, which is RG photoresistor, which changes the size of the resistance by the ambient light intensity changes, when the ambient illuminance is high, RO resistance was low, so the capacitor C charge rate slows down, vs SCR conduction angle becomes small, light H hair brightness is reduced if the ambient illumination is gradually reduced, the slip streaming effect is reduced, so the capacitor C charging rate of speed, vs SCR conduction angle is gradually increased, the brightness of the lamp H also will be increased in order to ensure the illuminated face in light of the stable and unchanging purpose.