(function(){
let w = window.innerWidth;
function setHeaderCssVar() {
const headerEle = document.getElementById('shoplaza-section-header');
if(!headerEle){ return };
document.body.style.setProperty('--window-height', `${window.innerHeight}px`);
document.body.style.setProperty('--header-height', `${headerEle.clientHeight}px`);
const mdScorllHideEle = headerEle.querySelector('.header__mobile .header__scroll_hide');
if (mdScorllHideEle) {
document.body.style.setProperty('--header-scroll-hide-height-md', `${mdScorllHideEle.clientHeight}px`);
}
const pcScorllHideEle = headerEle.querySelector('.header__desktop .header__scroll_hide');
if (pcScorllHideEle) {
document.body.style.setProperty('--header-scroll-hide-height-pc', `${pcScorllHideEle.clientHeight}px`);
}
}
function handlResize() {
if(w == window.innerWidth){return};
w = window.innerWidth;
setHeaderCssVar();
};
function init(){
setHeaderCssVar();
window.removeEventListener('resize', window._theme_header_listener)
window._theme_header_listener = handlResize;
window.addEventListener('resize', window._theme_header_listener);
}
init();
})();
${data.index + 1}/6
Description
Basketball Game 24 Seconds Digital Countdown Timer Circuit Electronic Parts Kit DIY Electronic Trainer Kit
Product Description
The circuit consists of 5 parts: second pulse generator, counter, decoder, display circuit and alarm circuit. The counter decrements from 24 to 0 in seconds, and finally pauses from 0 to 24. When the start button is pressed, it enters the next countdown count.
Specification
item
value
Power supply voltage
DC 3-5V, remember that the voltage cannot be greater than 5V, otherwise the digital tube will be burned out, 4.5V is recommended
Board size
6.5*8.5cm
Installation Instructions
Button definition
Start: Start the button, after the countdown is over, press this button to start the counter Begin counting down. Reset: When this key is pressed, no matter what working state it is working in, the counter will immediately reset to the preset value of 24 seconds. Pause: When this button is kept pressed, the counter pauses counting. After the button is released, the timing continues. Reminder: If the buzzer is quiet or does not sound, you can directly use the cut pins to short-circuit and solder R7. The display may be messy after power-on, just press the reset button.
Welding tips
Pay attention to the positive and negative poles of the power supply, the resistance value should correspond to the one on the board, the chip model is inserted in the corresponding position, and the chip notch direction is all upwards. Both LEDs and electrolytic capacitors have long pins that are positive.
