LED electric drive circuit principle diagram, analytic find more straightforward
The capacitor does not communicate through the circuit. It operates only in two processes: charging and discharging.
The transistor E pole and the B pole have an emitter junction and the B has a junction voltage, and the silicon material transistor is 0.5 to 0.7V germanium material transistors with junction voltages of 0.2 to 0.3V. This does not need to be judged by the transistor manual with explicit arguments.
Process control diagram transistor mainly occurred in VT1, the work process is as follows, the capacitor connected to the VT1 on the left base potential basically fixed, when the VT2 is switched on, the capacitor potential decreased, because the capacitor voltage can not have a mutation, so as the drop-down role for VT1 base, this action prompted VT2 more saturated conduction. During the process, the capacitor is charged full, so that the base current of the VT1 is weakened. Then the collector potential of VT2 increased, the trend of the rise of the feedback base potential effect of VT1 capacitor is increased, which led to the rise of VT1 transistor appeared off, it causes the VT2 cut-off cut-off, inductance coil form boost, resulting in two transistor boost completely off, thus completing a shock cycle.
