کیت فلشر NE555 / CD4017

Specific parameters:


Supply voltage: 3-5V
PCB size: 88*25mm
This kit is mainly composed of a clock generation circuit and a decimal counter circuit
Self-excited multivibrator with NE555 as the core, the power supply charges capacitor C2 through R2, R1, VR1. When C2 starts charging, the 2 pin of U1 is still at low level, so the output pin 3 is high When the power supply is charged to 2/3 of the power supply voltage through R2, R1, VR1 to C2, the level of the output pin 3 goes from high to low, the internal discharge tube of U1 turns on, and the capacitor C2 discharges through 7 pins of VR1, R1, and U1. Until the voltage across C2 is lower than the 1/3 supply voltage, U1's 3-pin level is changed from low to high again. C1 is recharged again, so that the cycle forms oscillation. Charging time is: 0.695(R2+R1+VR1)C2, discharge time is: 0.695(VR1+R1)C2, adjusting VR1 can control the output frequency of the oscillator, U1 clock oscillation signal is continuously added to U2's 14 pin, There are 10 LEDs connected to the 10 output terminals of U2. When the 10 output terminals of U2 generate high level in turn under the action of the clock signal, D1--D10 are turned on one by one, thereby forming a streamer effect.