{"product_id":"yidab-soldering-practice-kit-diy-plug-in-flowing-water-light-soldering-kit-with-cd4017-and-nj5655-ideal-for-beginners-st","title":"Yidab Soldering Practice Kit DIY Plug - in Flowing Water Light Soldering Kit - with CD4017 and NJ5655 - Ideal for Beginners \u0026 ST","description":"\u003cp\u003eThis kit is mainly composed of a clock generation circuit and a decimal counter circuit. It consists of a self-excited multivibrator with the NE555 as the core. The power supply charges the capacitor C1 through resistors R2, R3 and R4. When C1 just starts to be charged, pin 2 of the NE555 is still at a low level, so pin 3 (the output terminal) is at a high level. When the power supply charges C1 through R2, R3 and R4 to two-thirds of the power supply voltage, the level of pin 3 of the output terminal changes from high to low, and the internal discharge tube of the NE555 turns on. Then the capacitor C1 discharges through R4, R3 and pin 7 of the NE555. Until the voltage across C1 is lower than one-third of the power supply voltage, the level of pin 3 of the NE555 changes from low level to high level again, and C1 is charged again. In this way, oscillation is formed in a cycle. The charging time is 0.695  (R2 + R3 + R4)  C1, and the discharging time is 0.695  (R4 + R3)  C1. Adjusting R4 can control the output frequency of the oscillator. The clock oscillation signal of the NE555 is continuously applied to pin 14 of the CD4017. There are 10 LEDs connected to the 10 output terminals of the CD4017. When the 10 output terminals of the CD4017 alternately generate high levels under the action of the clock signal, D1 - D10 are lit up in turn, thus forming a flowing light effect. Adjusting R4 can adjust the flowing speed of the LEDs.\u003c\/p\u003e","brand":"Yidab","offers":[{"title":"Default Title","offer_id":45183181389939,"sku":"WBHDWB0BNPXBWHM","price":10.49,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0643\/1958\/6419\/files\/71XnZWKGvML.jpg?v=1783411236","url":"https:\/\/slickpurchase.com\/products\/yidab-soldering-practice-kit-diy-plug-in-flowing-water-light-soldering-kit-with-cd4017-and-nj5655-ideal-for-beginners-st","provider":"Slickpurchase","version":"1.0","type":"link"}