LM317T Voltage Regulator with Pass Transistor

Test for the AC Time Delay circuit using Triacs electroschematics.com The C1 capacitor will charge up gradually through the R1 resistor until the voltage across the capacitor reaches the threshold voltage of the thyristor (Vc1=0.7V). The voltage across the capacitor, Vc1 at any instant in time during the charging period is given as: Vc1 = Vs[1 -- e^(-t/RC) ] Vs= the peak supply voltage If we use 230 Vac, the peak voltage is therefore 230* 1.41, which is about 325 V. Do the math and obtain 70ms time delay. Later the triac turn on for Vc2 = Vgt +Igt*R3 ~ 4V Second time delay ~ 270 ms In theory the total time delay = 70+270= 340ms In practice tested using BT139, TIC206M, TIC216M, TIC226M, BTA16. No succes for TIC226M, BTA16. Time delay for : BT139 ~ 3-4 s TIC206M ~0.3 s TIC216M ~ 0.5-0.6s We have measured the illumination on a work table for the 100W light bulb. Ambient illumination =70 lux, typical illumination for light bulb power supply direct connection =1100 lux. Using BT139 ~300 lux TIC206 ~ 1100 lux TIC216M ~450 lux



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