Three-way flashing light controller

The entire controller consists of four parts: main control circuit, drive circuit, output circuit and power supply. The main control circuit consists of VTI ~
VT3, which are connected to form a three-stage common emitter amplifier. Due to the coupling effect of capacitors C1 ~ C3, strong oscillation occurs.
After the circuit oscillates, the transistors VI'I ~ VT3 are all in the switching state, and are in the conductive state. There is a periodic flipping between the on-state and the off-state
, but at any time there are always two transistors in the on-state and one transistor in the off-state. The drive circuit
consists of VT4~VT6, and the output circuit consists of VS1~VS3.
    In the main control circuit, if a certain transistor such as VT1 is in a cut-off state, its collector outputs a high level. This high level turns on
the driving transistor VT4 through the resistor R7, and the thyristor VSI is triggered to open, and the circuit color The lamp Hi lights up and shines. If
a certain transistor such as VT3 is in the conducting state, its collector outputs a low level, the driving tube VT6 of this road is cut off, and the thyristor
VS3 of this road is in a blocking state because it cannot get the trigger current, and the lantern H3 of this road is also in a blocking state. Then it went out. Since the switching status of the three
transistors of the main control circuit is constantly flipping, the three colored lights H1~H3 will light up and go out in sequence. Each colored light can
be composed of several colored lights. Press it in the space at a certain time. Arranging them in sequence can form a "flowing water". The potentiometer RP is used to adjust
the flipping frequency of the main control circuit, so adjusting the potentiometer RP can adjust the "flow" speed of the lantern
.     The power circuit consists of transformer T, diode VD and capacitor C4. It outputs about 7V DC voltage for the entire circuit
.