em the fluorescent lamp fl1 would not turn on again as indicated before this was because the arc voltage was reduced by the dimmer means to ensure positive start up the lamp required minimum ignition voltage on power up of the electronic ballast transistor q1 is normally in the off condition thus resistor r8 is in series with the dimmer circuit consisting of the dimmer coil em the electromagnet the potentiometer r5 and load resistor r4 resistor r8 is of such a value that it will restrict the current flowing through the dimmer coil to a value equal to a high level of dimming this will be true regardless of the setting of resistor r5 without any significant dc field being generated by dimming coil em the switching toroids dt 1a and dt 1b in the ballast circuitry will produce a complete duty cycle on time of the power transistors q1 and q2 full power will normally flow to a lamp fl1 after a delay of about one second resistor r8 is by passed by transistor q3 being turned on this results in the dimming circuit being connected as intended thus if the dimmer at resistor r5 is set at some reduced level the lamp fl1 will be appropriately dimmed a resistor r6 in combination with capacitor t5 and resistor r7 are employed to form an rc time delay circuit initially.