MENU

【明明綠燈轉眼變成紅燈】第一話 - 555TIMER

0
2571
0

收到一個新委託,要做底部 PLAY-MOBIL COMPATIABLE 嘅紅綠燈一支,會自動轉燈嘅,不如一步步,一齊做!

嚟,睇下個草稿先 : )
rr

今次會用朋友 VP 介紹嘅 555TIMER 做大腦而棄用 ARDUINO,因為係送比細路仔用嘅。
IMG_8990
講兩句 555TIMER 乜料,其實佢係一粒多功能 IC,駁上電源電線就可以用作開關 SCHEDULER,今次只會用佢嘅 ASTABLE MODE,又稱 OSCILLATOR MODE,顧名思義,佢會不停 ON-OFF 咁啦。跟著電路圖駁好線一開火牛,已經見到兩盞燈互閃,正正子!

條算式是咁的:
Time_total = 0.7 * (R1 + 2R2) * C1
Time_high = 0.7 * (R1 + R2) * C1
Time_low = 0.7 * R2 * C1

由於件作品係比小朋友玩嘅,我估總時間大約15秒其實差唔多
咁代返 D數字
我要用嘅 R1係3.1K,R2係10K,C1 係1000uF 總時間計出來係16.17秒,但實制實驗時間係14.68秒,原因係 RESISTOR 有約 5% 誤差,代入計返再對下時間其係係啱咁滯。
Time_total = 0.7*(3.1+2*10)*1.0 = 16.17 (下限誤差*0.95*0.95) = 14.59
Time_high = 0.7*(3.1+10)*1.0 = 9.17 (下限誤差*0.95*0.95) = 8.27
Time_low = 0.7*10*1.0 = 7 (下限誤差*0.95*0.95) = 6.3

要特別嗚謝多一次兩位廢柴逹人級朋友 VP PANG / RADA SUN 成日都教我好多嘢
咁下一步又點呢?黃燈呢?三色喎HI你!回水呀!!!
咪住先,比少少時間大家齊齊諗下 XD
請看下回分解啦!

Leave a Comment!

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>