Lighting delay circuit using single-junction transistor Part 2b

(2) Lighting delay-off circuit 2 using single - junction transistor The     circuit is shown in Figure 2-42. Figure 2-42 (a) uses a capacitor to step down the voltage, and the transistor VT2 is of the PNP type; Figure 2-42 (b) uses a transformer to step down the voltage (safer), and the transistors VTz and VT3 are of the NPN type.