Roadblock flashing warning light circuit (3)

The roadblock flashing warning light is made of the H1.9811 single-can flash light control integrated circuit produced by Wuxi Aixinke Microelectronics Co., Ltd.
The HL9811 integrates an RC oscillator, frequency divider, output
buffer amplifier, shaping circuit, Power output circuit, etc. HL9811 has
two types . This circuit adopts T()-92 package. Its ① pin is the negative terminal v,, of the power supply; ② pin is the flash output terminal () LT;
③Pin is the power terminal V... After
    the 220v alternating current
is rectified by VDl-VD4, one
channel is directly used as the power supply for the lamp E
, and the other channel is passed through R to step down,
current limit, vs stabilize the voltage and (1. Filter
output 12V DC voltage supplies power for
light control circuits, flash integrated circuits
, etc. VT1 and VT2
form a Darlington tube, which, together with the photoresistor
Rl and the resistor R, forms a light power switch, RI during the day. It shows low resistance when exposed to light, so The Darlington
tubes (i.e. VT1, VT2) are cut off, the power switch is turned off, the subsequent circuit does not operate due to power loss, the thyristor VT4
is also turned off, and the warning light E lights up. When night falls, the resistance of R1J gradually increases, VTI The potential of the substrate also
increases. When the growth reaches a certain value, the Darlington tube composed of Vri and VT2 is turned on, which provides the necessary 12V DC voltage for subsequent circuits to work. When H1.9811 obtains the normal necessary DC voltage , its output terminal outputs a square wave pulse signal, which is amplified by the diode VT3 and then added to the fJ of the thyristor VT4, causing the gap of VT4 to open and close, thus causing the warning light E to flash.     The flashing rate of the lamp H is affected by the integrated block H1.98 is controlled by the internal oscillator. The oscillation frequency is in the range of 0.5~2Hz and cannot be adjusted by external components. If you feel that the oscillation frequency is not suitable, you can "request the manufacturer to customize it. " 600V small plastic one-way gate tubes such as MCR100-8, etc. F is a red incandescent light bulb below 100W.