Visual fatigue eliminator circuit diagram

Photocoupler

When reading and writing for a long time, the distance between the eyes and the book is too close, and the light is too dark, which is the main cause of the decline in vision. The visual fatigue eliminator described in this example can help eliminate visual fatigue and prevent the occurrence of myopia.
Circuit Operation The visual fatigue eliminator circuit consists of a pulse generator, a counter divider, and an LED display circuit, as shown.

In the circuit, the pulse generator circuit is composed of time base integrated circuit IC 1, resistor R1, R2, diode VD1 and capacitors C1, C2; the counting frequency divider circuit is composed of decimal counting/pulse distributor integrated circuit IC2 and diode VD2 - VD11 The LED display circuit is composed of resistors R3 - R6 and LEDs VLl - V L4. After the pulse generator is energized, the oscillation signal is output from pin 3 of ICl as the count pulse of IC2. After IC2 is powered on and reset, under the action of input pulse, its YO-Y9 end sequentially outputs a high level, driving VL1-VM to illuminate continuously according to a certain law. When the YO terminal, the Y4 terminal, and the Y7 terminal of the IC2 output a high level, the VLI is lit; when the Y1 terminal and the Y6 terminal output a high level, the V L2 is lit; the Y2 terminal, the Y5 terminal, and the Y9 terminal output a high voltage. Normally, V L3 is lit. When the high level is output at the Y3 terminal and the Y8 terminal, V L4 is lit.
The light-emitting diodes VLI-VL4 have a light-emitting sequence of VL1-VL2-L3-VL4-VL1-VL3-VL2-VL1-VL4-VL3-VL1-VL2 which is continuously circulated. Install 4 LEDs (VLI-V) separately at the upper, lower, left and right symmetrical positions of a plane (the distance between the two LEDs corresponding to the upper, lower or left and right sides is about 30mm) . When the eye is tired, the eye rotates continuously with the light-emitting diode (the distance between the eye and the light-emitting diode is 25 - 30cm), so as to eliminate vision fatigue and prevent myopia.
Component selection
Rl-R6 uses 1/4W carbon film resistor or metal film resistor. C1 and C2 use monolithic capacitors or polyester capacitors. VD1-VD11 selects 1 N4148 type silicon switch diode for use. VU-VL4 selects green high-brightness light-emitting diodes with Φ5mm or Φmm. IC 1 selects NE555 type time base integrated circuit; IC2 selects CD4017 type decimal counting/pulse distributor integrated circuit.